.

qwen/nodejs/node_modules/eslint/lib/linter/apply-disable-directives.js

@@ -0,0 +1,465 @@
+/**
+ * @fileoverview A module that filters reported problems based on `eslint-disable` and `eslint-enable` comments
+ * @author Teddy Katz
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Typedefs
+//------------------------------------------------------------------------------
+
+/** @typedef {import("../shared/types").LintMessage} LintMessage */
+
+//------------------------------------------------------------------------------
+// Module Definition
+//------------------------------------------------------------------------------
+
+const escapeRegExp = require("escape-string-regexp");
+
+/**
+ * Compares the locations of two objects in a source file
+ * @param {{line: number, column: number}} itemA The first object
+ * @param {{line: number, column: number}} itemB The second object
+ * @returns {number} A value less than 1 if itemA appears before itemB in the source file, greater than 1 if
+ * itemA appears after itemB in the source file, or 0 if itemA and itemB have the same location.
+ */
+function compareLocations(itemA, itemB) {
+    return itemA.line - itemB.line || itemA.column - itemB.column;
+}
+
+/**
+ * Groups a set of directives into sub-arrays by their parent comment.
+ * @param {Iterable<Directive>} directives Unused directives to be removed.
+ * @returns {Directive[][]} Directives grouped by their parent comment.
+ */
+function groupByParentComment(directives) {
+    const groups = new Map();
+
+    for (const directive of directives) {
+        const { unprocessedDirective: { parentComment } } = directive;
+
+        if (groups.has(parentComment)) {
+            groups.get(parentComment).push(directive);
+        } else {
+            groups.set(parentComment, [directive]);
+        }
+    }
+
+    return [...groups.values()];
+}
+
+/**
+ * Creates removal details for a set of directives within the same comment.
+ * @param {Directive[]} directives Unused directives to be removed.
+ * @param {Token} commentToken The backing Comment token.
+ * @returns {{ description, fix, unprocessedDirective }[]} Details for later creation of output Problems.
+ */
+function createIndividualDirectivesRemoval(directives, commentToken) {
+
+    /*
+     * `commentToken.value` starts right after `//` or `/*`.
+     * All calculated offsets will be relative to this index.
+     */
+    const commentValueStart = commentToken.range[0] + "//".length;
+
+    // Find where the list of rules starts. `\S+` matches with the directive name (e.g. `eslint-disable-line`)
+    const listStartOffset = /^\s*\S+\s+/u.exec(commentToken.value)[0].length;
+
+    /*
+     * Get the list text without any surrounding whitespace. In order to preserve the original
+     * formatting, we don't want to change that whitespace.
+     *
+     *     // eslint-disable-line rule-one , rule-two , rule-three -- comment
+     *                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+     */
+    const listText = commentToken.value
+        .slice(listStartOffset) // remove directive name and all whitespace before the list
+        .split(/\s-{2,}\s/u)[0] // remove `-- comment`, if it exists
+        .trimEnd(); // remove all whitespace after the list
+
+    /*
+     * We can assume that `listText` contains multiple elements.
+     * Otherwise, this function wouldn't be called - if there is
+     * only one rule in the list, then the whole comment must be removed.
+     */
+
+    return directives.map(directive => {
+        const { ruleId } = directive;
+
+        const regex = new RegExp(String.raw`(?:^|\s*,\s*)(?<quote>['"]?)${escapeRegExp(ruleId)}\k<quote>(?:\s*,\s*|$)`, "u");
+        const match = regex.exec(listText);
+        const matchedText = match[0];
+        const matchStartOffset = listStartOffset + match.index;
+        const matchEndOffset = matchStartOffset + matchedText.length;
+
+        const firstIndexOfComma = matchedText.indexOf(",");
+        const lastIndexOfComma = matchedText.lastIndexOf(",");
+
+        let removalStartOffset, removalEndOffset;
+
+        if (firstIndexOfComma !== lastIndexOfComma) {
+
+            /*
+             * Since there are two commas, this must one of the elements in the middle of the list.
+             * Matched range starts where the previous rule name ends, and ends where the next rule name starts.
+             *
+             *     // eslint-disable-line rule-one , rule-two , rule-three -- comment
+             *                                    ^^^^^^^^^^^^^^
+             *
+             * We want to remove only the content between the two commas, and also one of the commas.
+             *
+             *     // eslint-disable-line rule-one , rule-two , rule-three -- comment
+             *                                     ^^^^^^^^^^^
+             */
+            removalStartOffset = matchStartOffset + firstIndexOfComma;
+            removalEndOffset = matchStartOffset + lastIndexOfComma;
+
+        } else {
+
+            /*
+             * This is either the first element or the last element.
+             *
+             * If this is the first element, matched range starts where the first rule name starts
+             * and ends where the second rule name starts. This is exactly the range we want
+             * to remove so that the second rule name will start where the first one was starting
+             * and thus preserve the original formatting.
+             *
+             *     // eslint-disable-line rule-one , rule-two , rule-three -- comment
+             *                            ^^^^^^^^^^^
+             *
+             * Similarly, if this is the last element, we've already matched the range we want to
+             * remove. The previous rule name will end where the last one was ending, relative
+             * to the content on the right side.
+             *
+             *     // eslint-disable-line rule-one , rule-two , rule-three -- comment
+             *                                               ^^^^^^^^^^^^^
+             */
+            removalStartOffset = matchStartOffset;
+            removalEndOffset = matchEndOffset;
+        }
+
+        return {
+            description: `'${ruleId}'`,
+            fix: {
+                range: [
+                    commentValueStart + removalStartOffset,
+                    commentValueStart + removalEndOffset
+                ],
+                text: ""
+            },
+            unprocessedDirective: directive.unprocessedDirective
+        };
+    });
+}
+
+/**
+ * Creates a description of deleting an entire unused disable comment.
+ * @param {Directive[]} directives Unused directives to be removed.
+ * @param {Token} commentToken The backing Comment token.
+ * @returns {{ description, fix, unprocessedDirective }} Details for later creation of an output Problem.
+ */
+function createCommentRemoval(directives, commentToken) {
+    const { range } = commentToken;
+    const ruleIds = directives.filter(directive => directive.ruleId).map(directive => `'${directive.ruleId}'`);
+
+    return {
+        description: ruleIds.length <= 2
+            ? ruleIds.join(" or ")
+            : `${ruleIds.slice(0, ruleIds.length - 1).join(", ")}, or ${ruleIds[ruleIds.length - 1]}`,
+        fix: {
+            range,
+            text: " "
+        },
+        unprocessedDirective: directives[0].unprocessedDirective
+    };
+}
+
+/**
+ * Parses details from directives to create output Problems.
+ * @param {Iterable<Directive>} allDirectives Unused directives to be removed.
+ * @returns {{ description, fix, unprocessedDirective }[]} Details for later creation of output Problems.
+ */
+function processUnusedDirectives(allDirectives) {
+    const directiveGroups = groupByParentComment(allDirectives);
+
+    return directiveGroups.flatMap(
+        directives => {
+            const { parentComment } = directives[0].unprocessedDirective;
+            const remainingRuleIds = new Set(parentComment.ruleIds);
+
+            for (const directive of directives) {
+                remainingRuleIds.delete(directive.ruleId);
+            }
+
+            return remainingRuleIds.size
+                ? createIndividualDirectivesRemoval(directives, parentComment.commentToken)
+                : [createCommentRemoval(directives, parentComment.commentToken)];
+        }
+    );
+}
+
+/**
+ * Collect eslint-enable comments that are removing suppressions by eslint-disable comments.
+ * @param {Directive[]} directives The directives to check.
+ * @returns {Set<Directive>} The used eslint-enable comments
+ */
+function collectUsedEnableDirectives(directives) {
+
+    /**
+     * A Map of `eslint-enable` keyed by ruleIds that may be marked as used.
+     * If `eslint-enable` does not have a ruleId, the key will be `null`.
+     * @type {Map<string|null, Directive>}
+     */
+    const enabledRules = new Map();
+
+    /**
+     * A Set of `eslint-enable` marked as used.
+     * It is also the return value of `collectUsedEnableDirectives` function.
+     * @type {Set<Directive>}
+     */
+    const usedEnableDirectives = new Set();
+
+    /*
+     * Checks the directives backwards to see if the encountered `eslint-enable` is used by the previous `eslint-disable`,
+     * and if so, stores the `eslint-enable` in `usedEnableDirectives`.
+     */
+    for (let index = directives.length - 1; index >= 0; index--) {
+        const directive = directives[index];
+
+        if (directive.type === "disable") {
+            if (enabledRules.size === 0) {
+                continue;
+            }
+            if (directive.ruleId === null) {
+
+                // If encounter `eslint-disable` without ruleId,
+                // mark all `eslint-enable` currently held in enabledRules as used.
+                // e.g.
+                //    /* eslint-disable */ <- current directive
+                //    /* eslint-enable rule-id1 */ <- used
+                //    /* eslint-enable rule-id2 */ <- used
+                //    /* eslint-enable */ <- used
+                for (const enableDirective of enabledRules.values()) {
+                    usedEnableDirectives.add(enableDirective);
+                }
+                enabledRules.clear();
+            } else {
+                const enableDirective = enabledRules.get(directive.ruleId);
+
+                if (enableDirective) {
+
+                    // If encounter `eslint-disable` with ruleId, and there is an `eslint-enable` with the same ruleId in enabledRules,
+                    // mark `eslint-enable` with ruleId as used.
+                    // e.g.
+                    //    /* eslint-disable rule-id */ <- current directive
+                    //    /* eslint-enable rule-id */ <- used
+                    usedEnableDirectives.add(enableDirective);
+                } else {
+                    const enabledDirectiveWithoutRuleId = enabledRules.get(null);
+
+                    if (enabledDirectiveWithoutRuleId) {
+
+                        // If encounter `eslint-disable` with ruleId, and there is no `eslint-enable` with the same ruleId in enabledRules,
+                        // mark `eslint-enable` without ruleId as used.
+                        // e.g.
+                        //    /* eslint-disable rule-id */ <- current directive
+                        //    /* eslint-enable */ <- used
+                        usedEnableDirectives.add(enabledDirectiveWithoutRuleId);
+                    }
+                }
+            }
+        } else if (directive.type === "enable") {
+            if (directive.ruleId === null) {
+
+                // If encounter `eslint-enable` without ruleId, the `eslint-enable` that follows it are unused.
+                // So clear enabledRules.
+                // e.g.
+                //    /* eslint-enable */ <- current directive
+                //    /* eslint-enable rule-id *// <- unused
+                //    /* eslint-enable */ <- unused
+                enabledRules.clear();
+                enabledRules.set(null, directive);
+            } else {
+                enabledRules.set(directive.ruleId, directive);
+            }
+        }
+    }
+    return usedEnableDirectives;
+}
+
+/**
+ * This is the same as the exported function, except that it
+ * doesn't handle disable-line and disable-next-line directives, and it always reports unused
+ * disable directives.
+ * @param {Object} options options for applying directives. This is the same as the options
+ * for the exported function, except that `reportUnusedDisableDirectives` is not supported
+ * (this function always reports unused disable directives).
+ * @returns {{problems: LintMessage[], unusedDirectives: LintMessage[]}} An object with a list
+ * of problems (including suppressed ones) and unused eslint-disable directives
+ */
+function applyDirectives(options) {
+    const problems = [];
+    const usedDisableDirectives = new Set();
+
+    for (const problem of options.problems) {
+        let disableDirectivesForProblem = [];
+        let nextDirectiveIndex = 0;
+
+        while (
+            nextDirectiveIndex < options.directives.length &&
+            compareLocations(options.directives[nextDirectiveIndex], problem) <= 0
+        ) {
+            const directive = options.directives[nextDirectiveIndex++];
+
+            if (directive.ruleId === null || directive.ruleId === problem.ruleId) {
+                switch (directive.type) {
+                    case "disable":
+                        disableDirectivesForProblem.push(directive);
+                        break;
+
+                    case "enable":
+                        disableDirectivesForProblem = [];
+                        break;
+
+                    // no default
+                }
+            }
+        }
+
+        if (disableDirectivesForProblem.length > 0) {
+            const suppressions = disableDirectivesForProblem.map(directive => ({
+                kind: "directive",
+                justification: directive.unprocessedDirective.justification
+            }));
+
+            if (problem.suppressions) {
+                problem.suppressions = problem.suppressions.concat(suppressions);
+            } else {
+                problem.suppressions = suppressions;
+                usedDisableDirectives.add(disableDirectivesForProblem[disableDirectivesForProblem.length - 1]);
+            }
+        }
+
+        problems.push(problem);
+    }
+
+    const unusedDisableDirectivesToReport = options.directives
+        .filter(directive => directive.type === "disable" && !usedDisableDirectives.has(directive));
+
+
+    const unusedEnableDirectivesToReport = new Set(
+        options.directives.filter(directive => directive.unprocessedDirective.type === "enable")
+    );
+
+    /*
+     * If directives has the eslint-enable directive,
+     * check whether the eslint-enable comment is used.
+     */
+    if (unusedEnableDirectivesToReport.size > 0) {
+        for (const directive of collectUsedEnableDirectives(options.directives)) {
+            unusedEnableDirectivesToReport.delete(directive);
+        }
+    }
+
+    const processed = processUnusedDirectives(unusedDisableDirectivesToReport)
+        .concat(processUnusedDirectives(unusedEnableDirectivesToReport));
+
+    const unusedDirectives = processed
+        .map(({ description, fix, unprocessedDirective }) => {
+            const { parentComment, type, line, column } = unprocessedDirective;
+
+            let message;
+
+            if (type === "enable") {
+                message = description
+                    ? `Unused eslint-enable directive (no matching eslint-disable directives were found for ${description}).`
+                    : "Unused eslint-enable directive (no matching eslint-disable directives were found).";
+            } else {
+                message = description
+                    ? `Unused eslint-disable directive (no problems were reported from ${description}).`
+                    : "Unused eslint-disable directive (no problems were reported).";
+            }
+            return {
+                ruleId: null,
+                message,
+                line: type === "disable-next-line" ? parentComment.commentToken.loc.start.line : line,
+                column: type === "disable-next-line" ? parentComment.commentToken.loc.start.column + 1 : column,
+                severity: options.reportUnusedDisableDirectives === "warn" ? 1 : 2,
+                nodeType: null,
+                ...options.disableFixes ? {} : { fix }
+            };
+        });
+
+    return { problems, unusedDirectives };
+}
+
+/**
+ * Given a list of directive comments (i.e. metadata about eslint-disable and eslint-enable comments) and a list
+ * of reported problems, adds the suppression information to the problems.
+ * @param {Object} options Information about directives and problems
+ * @param {{
+ *      type: ("disable"|"enable"|"disable-line"|"disable-next-line"),
+ *      ruleId: (string|null),
+ *      line: number,
+ *      column: number,
+ *      justification: string
+ * }} options.directives Directive comments found in the file, with one-based columns.
+ * Two directive comments can only have the same location if they also have the same type (e.g. a single eslint-disable
+ * comment for two different rules is represented as two directives).
+ * @param {{ruleId: (string|null), line: number, column: number}[]} options.problems
+ * A list of problems reported by rules, sorted by increasing location in the file, with one-based columns.
+ * @param {"off" | "warn" | "error"} options.reportUnusedDisableDirectives If `"warn"` or `"error"`, adds additional problems for unused directives
+ * @param {boolean} options.disableFixes If true, it doesn't make `fix` properties.
+ * @returns {{ruleId: (string|null), line: number, column: number, suppressions?: {kind: string, justification: string}}[]}
+ * An object with a list of reported problems, the suppressed of which contain the suppression information.
+ */
+module.exports = ({ directives, disableFixes, problems, reportUnusedDisableDirectives = "off" }) => {
+    const blockDirectives = directives
+        .filter(directive => directive.type === "disable" || directive.type === "enable")
+        .map(directive => Object.assign({}, directive, { unprocessedDirective: directive }))
+        .sort(compareLocations);
+
+    const lineDirectives = directives.flatMap(directive => {
+        switch (directive.type) {
+            case "disable":
+            case "enable":
+                return [];
+
+            case "disable-line":
+                return [
+                    { type: "disable", line: directive.line, column: 1, ruleId: directive.ruleId, unprocessedDirective: directive },
+                    { type: "enable", line: directive.line + 1, column: 0, ruleId: directive.ruleId, unprocessedDirective: directive }
+                ];
+
+            case "disable-next-line":
+                return [
+                    { type: "disable", line: directive.line + 1, column: 1, ruleId: directive.ruleId, unprocessedDirective: directive },
+                    { type: "enable", line: directive.line + 2, column: 0, ruleId: directive.ruleId, unprocessedDirective: directive }
+                ];
+
+            default:
+                throw new TypeError(`Unrecognized directive type '${directive.type}'`);
+        }
+    }).sort(compareLocations);
+
+    const blockDirectivesResult = applyDirectives({
+        problems,
+        directives: blockDirectives,
+        disableFixes,
+        reportUnusedDisableDirectives
+    });
+    const lineDirectivesResult = applyDirectives({
+        problems: blockDirectivesResult.problems,
+        directives: lineDirectives,
+        disableFixes,
+        reportUnusedDisableDirectives
+    });
+
+    return reportUnusedDisableDirectives !== "off"
+        ? lineDirectivesResult.problems
+            .concat(blockDirectivesResult.unusedDirectives)
+            .concat(lineDirectivesResult.unusedDirectives)
+            .sort(compareLocations)
+        : lineDirectivesResult.problems;
+};

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/code-path-analyzer.js

@@ -0,0 +1,852 @@
+/**
+ * @fileoverview A class of the code path analyzer.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const assert = require("assert"),
+    { breakableTypePattern } = require("../../shared/ast-utils"),
+    CodePath = require("./code-path"),
+    CodePathSegment = require("./code-path-segment"),
+    IdGenerator = require("./id-generator"),
+    debug = require("./debug-helpers");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Checks whether or not a given node is a `case` node (not `default` node).
+ * @param {ASTNode} node A `SwitchCase` node to check.
+ * @returns {boolean} `true` if the node is a `case` node (not `default` node).
+ */
+function isCaseNode(node) {
+    return Boolean(node.test);
+}
+
+/**
+ * Checks if a given node appears as the value of a PropertyDefinition node.
+ * @param {ASTNode} node THe node to check.
+ * @returns {boolean} `true` if the node is a PropertyDefinition value,
+ *      false if not.
+ */
+function isPropertyDefinitionValue(node) {
+    const parent = node.parent;
+
+    return parent && parent.type === "PropertyDefinition" && parent.value === node;
+}
+
+/**
+ * Checks whether the given logical operator is taken into account for the code
+ * path analysis.
+ * @param {string} operator The operator found in the LogicalExpression node
+ * @returns {boolean} `true` if the operator is "&&" or "||" or "??"
+ */
+function isHandledLogicalOperator(operator) {
+    return operator === "&&" || operator === "||" || operator === "??";
+}
+
+/**
+ * Checks whether the given assignment operator is a logical assignment operator.
+ * Logical assignments are taken into account for the code path analysis
+ * because of their short-circuiting semantics.
+ * @param {string} operator The operator found in the AssignmentExpression node
+ * @returns {boolean} `true` if the operator is "&&=" or "||=" or "??="
+ */
+function isLogicalAssignmentOperator(operator) {
+    return operator === "&&=" || operator === "||=" || operator === "??=";
+}
+
+/**
+ * Gets the label if the parent node of a given node is a LabeledStatement.
+ * @param {ASTNode} node A node to get.
+ * @returns {string|null} The label or `null`.
+ */
+function getLabel(node) {
+    if (node.parent.type === "LabeledStatement") {
+        return node.parent.label.name;
+    }
+    return null;
+}
+
+/**
+ * Checks whether or not a given logical expression node goes different path
+ * between the `true` case and the `false` case.
+ * @param {ASTNode} node A node to check.
+ * @returns {boolean} `true` if the node is a test of a choice statement.
+ */
+function isForkingByTrueOrFalse(node) {
+    const parent = node.parent;
+
+    switch (parent.type) {
+        case "ConditionalExpression":
+        case "IfStatement":
+        case "WhileStatement":
+        case "DoWhileStatement":
+        case "ForStatement":
+            return parent.test === node;
+
+        case "LogicalExpression":
+            return isHandledLogicalOperator(parent.operator);
+
+        case "AssignmentExpression":
+            return isLogicalAssignmentOperator(parent.operator);
+
+        default:
+            return false;
+    }
+}
+
+/**
+ * Gets the boolean value of a given literal node.
+ *
+ * This is used to detect infinity loops (e.g. `while (true) {}`).
+ * Statements preceded by an infinity loop are unreachable if the loop didn't
+ * have any `break` statement.
+ * @param {ASTNode} node A node to get.
+ * @returns {boolean|undefined} a boolean value if the node is a Literal node,
+ *   otherwise `undefined`.
+ */
+function getBooleanValueIfSimpleConstant(node) {
+    if (node.type === "Literal") {
+        return Boolean(node.value);
+    }
+    return void 0;
+}
+
+/**
+ * Checks that a given identifier node is a reference or not.
+ *
+ * This is used to detect the first throwable node in a `try` block.
+ * @param {ASTNode} node An Identifier node to check.
+ * @returns {boolean} `true` if the node is a reference.
+ */
+function isIdentifierReference(node) {
+    const parent = node.parent;
+
+    switch (parent.type) {
+        case "LabeledStatement":
+        case "BreakStatement":
+        case "ContinueStatement":
+        case "ArrayPattern":
+        case "RestElement":
+        case "ImportSpecifier":
+        case "ImportDefaultSpecifier":
+        case "ImportNamespaceSpecifier":
+        case "CatchClause":
+            return false;
+
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "ArrowFunctionExpression":
+        case "ClassDeclaration":
+        case "ClassExpression":
+        case "VariableDeclarator":
+            return parent.id !== node;
+
+        case "Property":
+        case "PropertyDefinition":
+        case "MethodDefinition":
+            return (
+                parent.key !== node ||
+                parent.computed ||
+                parent.shorthand
+            );
+
+        case "AssignmentPattern":
+            return parent.key !== node;
+
+        default:
+            return true;
+    }
+}
+
+/**
+ * Updates the current segment with the head segment.
+ * This is similar to local branches and tracking branches of git.
+ *
+ * To separate the current and the head is in order to not make useless segments.
+ *
+ * In this process, both "onCodePathSegmentStart" and "onCodePathSegmentEnd"
+ * events are fired.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function forwardCurrentToHead(analyzer, node) {
+    const codePath = analyzer.codePath;
+    const state = CodePath.getState(codePath);
+    const currentSegments = state.currentSegments;
+    const headSegments = state.headSegments;
+    const end = Math.max(currentSegments.length, headSegments.length);
+    let i, currentSegment, headSegment;
+
+    // Fires leaving events.
+    for (i = 0; i < end; ++i) {
+        currentSegment = currentSegments[i];
+        headSegment = headSegments[i];
+
+        if (currentSegment !== headSegment && currentSegment) {
+
+            const eventName = currentSegment.reachable
+                ? "onCodePathSegmentEnd"
+                : "onUnreachableCodePathSegmentEnd";
+
+            debug.dump(`${eventName} ${currentSegment.id}`);
+
+            analyzer.emitter.emit(
+                eventName,
+                currentSegment,
+                node
+            );
+        }
+    }
+
+    // Update state.
+    state.currentSegments = headSegments;
+
+    // Fires entering events.
+    for (i = 0; i < end; ++i) {
+        currentSegment = currentSegments[i];
+        headSegment = headSegments[i];
+
+        if (currentSegment !== headSegment && headSegment) {
+
+            const eventName = headSegment.reachable
+                ? "onCodePathSegmentStart"
+                : "onUnreachableCodePathSegmentStart";
+
+            debug.dump(`${eventName} ${headSegment.id}`);
+
+            CodePathSegment.markUsed(headSegment);
+            analyzer.emitter.emit(
+                eventName,
+                headSegment,
+                node
+            );
+        }
+    }
+
+}
+
+/**
+ * Updates the current segment with empty.
+ * This is called at the last of functions or the program.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function leaveFromCurrentSegment(analyzer, node) {
+    const state = CodePath.getState(analyzer.codePath);
+    const currentSegments = state.currentSegments;
+
+    for (let i = 0; i < currentSegments.length; ++i) {
+        const currentSegment = currentSegments[i];
+        const eventName = currentSegment.reachable
+            ? "onCodePathSegmentEnd"
+            : "onUnreachableCodePathSegmentEnd";
+
+        debug.dump(`${eventName} ${currentSegment.id}`);
+
+        analyzer.emitter.emit(
+            eventName,
+            currentSegment,
+            node
+        );
+    }
+
+    state.currentSegments = [];
+}
+
+/**
+ * Updates the code path due to the position of a given node in the parent node
+ * thereof.
+ *
+ * For example, if the node is `parent.consequent`, this creates a fork from the
+ * current path.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function preprocess(analyzer, node) {
+    const codePath = analyzer.codePath;
+    const state = CodePath.getState(codePath);
+    const parent = node.parent;
+
+    switch (parent.type) {
+
+        // The `arguments.length == 0` case is in `postprocess` function.
+        case "CallExpression":
+            if (parent.optional === true && parent.arguments.length >= 1 && parent.arguments[0] === node) {
+                state.makeOptionalRight();
+            }
+            break;
+        case "MemberExpression":
+            if (parent.optional === true && parent.property === node) {
+                state.makeOptionalRight();
+            }
+            break;
+
+        case "LogicalExpression":
+            if (
+                parent.right === node &&
+                isHandledLogicalOperator(parent.operator)
+            ) {
+                state.makeLogicalRight();
+            }
+            break;
+
+        case "AssignmentExpression":
+            if (
+                parent.right === node &&
+                isLogicalAssignmentOperator(parent.operator)
+            ) {
+                state.makeLogicalRight();
+            }
+            break;
+
+        case "ConditionalExpression":
+        case "IfStatement":
+
+            /*
+             * Fork if this node is at `consequent`/`alternate`.
+             * `popForkContext()` exists at `IfStatement:exit` and
+             * `ConditionalExpression:exit`.
+             */
+            if (parent.consequent === node) {
+                state.makeIfConsequent();
+            } else if (parent.alternate === node) {
+                state.makeIfAlternate();
+            }
+            break;
+
+        case "SwitchCase":
+            if (parent.consequent[0] === node) {
+                state.makeSwitchCaseBody(false, !parent.test);
+            }
+            break;
+
+        case "TryStatement":
+            if (parent.handler === node) {
+                state.makeCatchBlock();
+            } else if (parent.finalizer === node) {
+                state.makeFinallyBlock();
+            }
+            break;
+
+        case "WhileStatement":
+            if (parent.test === node) {
+                state.makeWhileTest(getBooleanValueIfSimpleConstant(node));
+            } else {
+                assert(parent.body === node);
+                state.makeWhileBody();
+            }
+            break;
+
+        case "DoWhileStatement":
+            if (parent.body === node) {
+                state.makeDoWhileBody();
+            } else {
+                assert(parent.test === node);
+                state.makeDoWhileTest(getBooleanValueIfSimpleConstant(node));
+            }
+            break;
+
+        case "ForStatement":
+            if (parent.test === node) {
+                state.makeForTest(getBooleanValueIfSimpleConstant(node));
+            } else if (parent.update === node) {
+                state.makeForUpdate();
+            } else if (parent.body === node) {
+                state.makeForBody();
+            }
+            break;
+
+        case "ForInStatement":
+        case "ForOfStatement":
+            if (parent.left === node) {
+                state.makeForInOfLeft();
+            } else if (parent.right === node) {
+                state.makeForInOfRight();
+            } else {
+                assert(parent.body === node);
+                state.makeForInOfBody();
+            }
+            break;
+
+        case "AssignmentPattern":
+
+            /*
+             * Fork if this node is at `right`.
+             * `left` is executed always, so it uses the current path.
+             * `popForkContext()` exists at `AssignmentPattern:exit`.
+             */
+            if (parent.right === node) {
+                state.pushForkContext();
+                state.forkBypassPath();
+                state.forkPath();
+            }
+            break;
+
+        default:
+            break;
+    }
+}
+
+/**
+ * Updates the code path due to the type of a given node in entering.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function processCodePathToEnter(analyzer, node) {
+    let codePath = analyzer.codePath;
+    let state = codePath && CodePath.getState(codePath);
+    const parent = node.parent;
+
+    /**
+     * Creates a new code path and trigger the onCodePathStart event
+     * based on the currently selected node.
+     * @param {string} origin The reason the code path was started.
+     * @returns {void}
+     */
+    function startCodePath(origin) {
+        if (codePath) {
+
+            // Emits onCodePathSegmentStart events if updated.
+            forwardCurrentToHead(analyzer, node);
+            debug.dumpState(node, state, false);
+        }
+
+        // Create the code path of this scope.
+        codePath = analyzer.codePath = new CodePath({
+            id: analyzer.idGenerator.next(),
+            origin,
+            upper: codePath,
+            onLooped: analyzer.onLooped
+        });
+        state = CodePath.getState(codePath);
+
+        // Emits onCodePathStart events.
+        debug.dump(`onCodePathStart ${codePath.id}`);
+        analyzer.emitter.emit("onCodePathStart", codePath, node);
+    }
+
+    /*
+     * Special case: The right side of class field initializer is considered
+     * to be its own function, so we need to start a new code path in this
+     * case.
+     */
+    if (isPropertyDefinitionValue(node)) {
+        startCodePath("class-field-initializer");
+
+        /*
+         * Intentional fall through because `node` needs to also be
+         * processed by the code below. For example, if we have:
+         *
+         * class Foo {
+         *     a = () => {}
+         * }
+         *
+         * In this case, we also need start a second code path.
+         */
+
+    }
+
+    switch (node.type) {
+        case "Program":
+            startCodePath("program");
+            break;
+
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "ArrowFunctionExpression":
+            startCodePath("function");
+            break;
+
+        case "StaticBlock":
+            startCodePath("class-static-block");
+            break;
+
+        case "ChainExpression":
+            state.pushChainContext();
+            break;
+        case "CallExpression":
+            if (node.optional === true) {
+                state.makeOptionalNode();
+            }
+            break;
+        case "MemberExpression":
+            if (node.optional === true) {
+                state.makeOptionalNode();
+            }
+            break;
+
+        case "LogicalExpression":
+            if (isHandledLogicalOperator(node.operator)) {
+                state.pushChoiceContext(
+                    node.operator,
+                    isForkingByTrueOrFalse(node)
+                );
+            }
+            break;
+
+        case "AssignmentExpression":
+            if (isLogicalAssignmentOperator(node.operator)) {
+                state.pushChoiceContext(
+                    node.operator.slice(0, -1), // removes `=` from the end
+                    isForkingByTrueOrFalse(node)
+                );
+            }
+            break;
+
+        case "ConditionalExpression":
+        case "IfStatement":
+            state.pushChoiceContext("test", false);
+            break;
+
+        case "SwitchStatement":
+            state.pushSwitchContext(
+                node.cases.some(isCaseNode),
+                getLabel(node)
+            );
+            break;
+
+        case "TryStatement":
+            state.pushTryContext(Boolean(node.finalizer));
+            break;
+
+        case "SwitchCase":
+
+            /*
+             * Fork if this node is after the 2st node in `cases`.
+             * It's similar to `else` blocks.
+             * The next `test` node is processed in this path.
+             */
+            if (parent.discriminant !== node && parent.cases[0] !== node) {
+                state.forkPath();
+            }
+            break;
+
+        case "WhileStatement":
+        case "DoWhileStatement":
+        case "ForStatement":
+        case "ForInStatement":
+        case "ForOfStatement":
+            state.pushLoopContext(node.type, getLabel(node));
+            break;
+
+        case "LabeledStatement":
+            if (!breakableTypePattern.test(node.body.type)) {
+                state.pushBreakContext(false, node.label.name);
+            }
+            break;
+
+        default:
+            break;
+    }
+
+    // Emits onCodePathSegmentStart events if updated.
+    forwardCurrentToHead(analyzer, node);
+    debug.dumpState(node, state, false);
+}
+
+/**
+ * Updates the code path due to the type of a given node in leaving.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function processCodePathToExit(analyzer, node) {
+
+    const codePath = analyzer.codePath;
+    const state = CodePath.getState(codePath);
+    let dontForward = false;
+
+    switch (node.type) {
+        case "ChainExpression":
+            state.popChainContext();
+            break;
+
+        case "IfStatement":
+        case "ConditionalExpression":
+            state.popChoiceContext();
+            break;
+
+        case "LogicalExpression":
+            if (isHandledLogicalOperator(node.operator)) {
+                state.popChoiceContext();
+            }
+            break;
+
+        case "AssignmentExpression":
+            if (isLogicalAssignmentOperator(node.operator)) {
+                state.popChoiceContext();
+            }
+            break;
+
+        case "SwitchStatement":
+            state.popSwitchContext();
+            break;
+
+        case "SwitchCase":
+
+            /*
+             * This is the same as the process at the 1st `consequent` node in
+             * `preprocess` function.
+             * Must do if this `consequent` is empty.
+             */
+            if (node.consequent.length === 0) {
+                state.makeSwitchCaseBody(true, !node.test);
+            }
+            if (state.forkContext.reachable) {
+                dontForward = true;
+            }
+            break;
+
+        case "TryStatement":
+            state.popTryContext();
+            break;
+
+        case "BreakStatement":
+            forwardCurrentToHead(analyzer, node);
+            state.makeBreak(node.label && node.label.name);
+            dontForward = true;
+            break;
+
+        case "ContinueStatement":
+            forwardCurrentToHead(analyzer, node);
+            state.makeContinue(node.label && node.label.name);
+            dontForward = true;
+            break;
+
+        case "ReturnStatement":
+            forwardCurrentToHead(analyzer, node);
+            state.makeReturn();
+            dontForward = true;
+            break;
+
+        case "ThrowStatement":
+            forwardCurrentToHead(analyzer, node);
+            state.makeThrow();
+            dontForward = true;
+            break;
+
+        case "Identifier":
+            if (isIdentifierReference(node)) {
+                state.makeFirstThrowablePathInTryBlock();
+                dontForward = true;
+            }
+            break;
+
+        case "CallExpression":
+        case "ImportExpression":
+        case "MemberExpression":
+        case "NewExpression":
+        case "YieldExpression":
+            state.makeFirstThrowablePathInTryBlock();
+            break;
+
+        case "WhileStatement":
+        case "DoWhileStatement":
+        case "ForStatement":
+        case "ForInStatement":
+        case "ForOfStatement":
+            state.popLoopContext();
+            break;
+
+        case "AssignmentPattern":
+            state.popForkContext();
+            break;
+
+        case "LabeledStatement":
+            if (!breakableTypePattern.test(node.body.type)) {
+                state.popBreakContext();
+            }
+            break;
+
+        default:
+            break;
+    }
+
+    // Emits onCodePathSegmentStart events if updated.
+    if (!dontForward) {
+        forwardCurrentToHead(analyzer, node);
+    }
+    debug.dumpState(node, state, true);
+}
+
+/**
+ * Updates the code path to finalize the current code path.
+ * @param {CodePathAnalyzer} analyzer The instance.
+ * @param {ASTNode} node The current AST node.
+ * @returns {void}
+ */
+function postprocess(analyzer, node) {
+
+    /**
+     * Ends the code path for the current node.
+     * @returns {void}
+     */
+    function endCodePath() {
+        let codePath = analyzer.codePath;
+
+        // Mark the current path as the final node.
+        CodePath.getState(codePath).makeFinal();
+
+        // Emits onCodePathSegmentEnd event of the current segments.
+        leaveFromCurrentSegment(analyzer, node);
+
+        // Emits onCodePathEnd event of this code path.
+        debug.dump(`onCodePathEnd ${codePath.id}`);
+        analyzer.emitter.emit("onCodePathEnd", codePath, node);
+        debug.dumpDot(codePath);
+
+        codePath = analyzer.codePath = analyzer.codePath.upper;
+        if (codePath) {
+            debug.dumpState(node, CodePath.getState(codePath), true);
+        }
+
+    }
+
+    switch (node.type) {
+        case "Program":
+        case "FunctionDeclaration":
+        case "FunctionExpression":
+        case "ArrowFunctionExpression":
+        case "StaticBlock": {
+            endCodePath();
+            break;
+        }
+
+        // The `arguments.length >= 1` case is in `preprocess` function.
+        case "CallExpression":
+            if (node.optional === true && node.arguments.length === 0) {
+                CodePath.getState(analyzer.codePath).makeOptionalRight();
+            }
+            break;
+
+        default:
+            break;
+    }
+
+    /*
+     * Special case: The right side of class field initializer is considered
+     * to be its own function, so we need to end a code path in this
+     * case.
+     *
+     * We need to check after the other checks in order to close the
+     * code paths in the correct order for code like this:
+     *
+     *
+     * class Foo {
+     *     a = () => {}
+     * }
+     *
+     * In this case, The ArrowFunctionExpression code path is closed first
+     * and then we need to close the code path for the PropertyDefinition
+     * value.
+     */
+    if (isPropertyDefinitionValue(node)) {
+        endCodePath();
+    }
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * The class to analyze code paths.
+ * This class implements the EventGenerator interface.
+ */
+class CodePathAnalyzer {
+
+    /**
+     * @param {EventGenerator} eventGenerator An event generator to wrap.
+     */
+    constructor(eventGenerator) {
+        this.original = eventGenerator;
+        this.emitter = eventGenerator.emitter;
+        this.codePath = null;
+        this.idGenerator = new IdGenerator("s");
+        this.currentNode = null;
+        this.onLooped = this.onLooped.bind(this);
+    }
+
+    /**
+     * Does the process to enter a given AST node.
+     * This updates state of analysis and calls `enterNode` of the wrapped.
+     * @param {ASTNode} node A node which is entering.
+     * @returns {void}
+     */
+    enterNode(node) {
+        this.currentNode = node;
+
+        // Updates the code path due to node's position in its parent node.
+        if (node.parent) {
+            preprocess(this, node);
+        }
+
+        /*
+         * Updates the code path.
+         * And emits onCodePathStart/onCodePathSegmentStart events.
+         */
+        processCodePathToEnter(this, node);
+
+        // Emits node events.
+        this.original.enterNode(node);
+
+        this.currentNode = null;
+    }
+
+    /**
+     * Does the process to leave a given AST node.
+     * This updates state of analysis and calls `leaveNode` of the wrapped.
+     * @param {ASTNode} node A node which is leaving.
+     * @returns {void}
+     */
+    leaveNode(node) {
+        this.currentNode = node;
+
+        /*
+         * Updates the code path.
+         * And emits onCodePathStart/onCodePathSegmentStart events.
+         */
+        processCodePathToExit(this, node);
+
+        // Emits node events.
+        this.original.leaveNode(node);
+
+        // Emits the last onCodePathStart/onCodePathSegmentStart events.
+        postprocess(this, node);
+
+        this.currentNode = null;
+    }
+
+    /**
+     * This is called on a code path looped.
+     * Then this raises a looped event.
+     * @param {CodePathSegment} fromSegment A segment of prev.
+     * @param {CodePathSegment} toSegment A segment of next.
+     * @returns {void}
+     */
+    onLooped(fromSegment, toSegment) {
+        if (fromSegment.reachable && toSegment.reachable) {
+            debug.dump(`onCodePathSegmentLoop ${fromSegment.id} -> ${toSegment.id}`);
+            this.emitter.emit(
+                "onCodePathSegmentLoop",
+                fromSegment,
+                toSegment,
+                this.currentNode
+            );
+        }
+    }
+}
+
+module.exports = CodePathAnalyzer;

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/code-path-segment.js

@@ -0,0 +1,263 @@
+/**
+ * @fileoverview The CodePathSegment class.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const debug = require("./debug-helpers");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Checks whether or not a given segment is reachable.
+ * @param {CodePathSegment} segment A segment to check.
+ * @returns {boolean} `true` if the segment is reachable.
+ */
+function isReachable(segment) {
+    return segment.reachable;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * A code path segment.
+ *
+ * Each segment is arranged in a series of linked lists (implemented by arrays)
+ * that keep track of the previous and next segments in a code path. In this way,
+ * you can navigate between all segments in any code path so long as you have a
+ * reference to any segment in that code path.
+ *
+ * When first created, the segment is in a detached state, meaning that it knows the
+ * segments that came before it but those segments don't know that this new segment
+ * follows it. Only when `CodePathSegment#markUsed()` is called on a segment does it
+ * officially become part of the code path by updating the previous segments to know
+ * that this new segment follows.
+ */
+class CodePathSegment {
+
+    /**
+     * Creates a new instance.
+     * @param {string} id An identifier.
+     * @param {CodePathSegment[]} allPrevSegments An array of the previous segments.
+     *   This array includes unreachable segments.
+     * @param {boolean} reachable A flag which shows this is reachable.
+     */
+    constructor(id, allPrevSegments, reachable) {
+
+        /**
+         * The identifier of this code path.
+         * Rules use it to store additional information of each rule.
+         * @type {string}
+         */
+        this.id = id;
+
+        /**
+         * An array of the next reachable segments.
+         * @type {CodePathSegment[]}
+         */
+        this.nextSegments = [];
+
+        /**
+         * An array of the previous reachable segments.
+         * @type {CodePathSegment[]}
+         */
+        this.prevSegments = allPrevSegments.filter(isReachable);
+
+        /**
+         * An array of all next segments including reachable and unreachable.
+         * @type {CodePathSegment[]}
+         */
+        this.allNextSegments = [];
+
+        /**
+         * An array of all previous segments including reachable and unreachable.
+         * @type {CodePathSegment[]}
+         */
+        this.allPrevSegments = allPrevSegments;
+
+        /**
+         * A flag which shows this is reachable.
+         * @type {boolean}
+         */
+        this.reachable = reachable;
+
+        // Internal data.
+        Object.defineProperty(this, "internal", {
+            value: {
+
+                // determines if the segment has been attached to the code path
+                used: false,
+
+                // array of previous segments coming from the end of a loop
+                loopedPrevSegments: []
+            }
+        });
+
+        /* c8 ignore start */
+        if (debug.enabled) {
+            this.internal.nodes = [];
+        }/* c8 ignore stop */
+    }
+
+    /**
+     * Checks a given previous segment is coming from the end of a loop.
+     * @param {CodePathSegment} segment A previous segment to check.
+     * @returns {boolean} `true` if the segment is coming from the end of a loop.
+     */
+    isLoopedPrevSegment(segment) {
+        return this.internal.loopedPrevSegments.includes(segment);
+    }
+
+    /**
+     * Creates the root segment.
+     * @param {string} id An identifier.
+     * @returns {CodePathSegment} The created segment.
+     */
+    static newRoot(id) {
+        return new CodePathSegment(id, [], true);
+    }
+
+    /**
+     * Creates a new segment and appends it after the given segments.
+     * @param {string} id An identifier.
+     * @param {CodePathSegment[]} allPrevSegments An array of the previous segments
+     *      to append to.
+     * @returns {CodePathSegment} The created segment.
+     */
+    static newNext(id, allPrevSegments) {
+        return new CodePathSegment(
+            id,
+            CodePathSegment.flattenUnusedSegments(allPrevSegments),
+            allPrevSegments.some(isReachable)
+        );
+    }
+
+    /**
+     * Creates an unreachable segment and appends it after the given segments.
+     * @param {string} id An identifier.
+     * @param {CodePathSegment[]} allPrevSegments An array of the previous segments.
+     * @returns {CodePathSegment} The created segment.
+     */
+    static newUnreachable(id, allPrevSegments) {
+        const segment = new CodePathSegment(id, CodePathSegment.flattenUnusedSegments(allPrevSegments), false);
+
+        /*
+         * In `if (a) return a; foo();` case, the unreachable segment preceded by
+         * the return statement is not used but must not be removed.
+         */
+        CodePathSegment.markUsed(segment);
+
+        return segment;
+    }
+
+    /**
+     * Creates a segment that follows given segments.
+     * This factory method does not connect with `allPrevSegments`.
+     * But this inherits `reachable` flag.
+     * @param {string} id An identifier.
+     * @param {CodePathSegment[]} allPrevSegments An array of the previous segments.
+     * @returns {CodePathSegment} The created segment.
+     */
+    static newDisconnected(id, allPrevSegments) {
+        return new CodePathSegment(id, [], allPrevSegments.some(isReachable));
+    }
+
+    /**
+     * Marks a given segment as used.
+     *
+     * And this function registers the segment into the previous segments as a next.
+     * @param {CodePathSegment} segment A segment to mark.
+     * @returns {void}
+     */
+    static markUsed(segment) {
+        if (segment.internal.used) {
+            return;
+        }
+        segment.internal.used = true;
+
+        let i;
+
+        if (segment.reachable) {
+
+            /*
+             * If the segment is reachable, then it's officially part of the
+             * code path. This loops through all previous segments to update
+             * their list of next segments. Because the segment is reachable,
+             * it's added to both `nextSegments` and `allNextSegments`.
+             */
+            for (i = 0; i < segment.allPrevSegments.length; ++i) {
+                const prevSegment = segment.allPrevSegments[i];
+
+                prevSegment.allNextSegments.push(segment);
+                prevSegment.nextSegments.push(segment);
+            }
+        } else {
+
+            /*
+             * If the segment is not reachable, then it's not officially part of the
+             * code path. This loops through all previous segments to update
+             * their list of next segments. Because the segment is not reachable,
+             * it's added only to `allNextSegments`.
+             */
+            for (i = 0; i < segment.allPrevSegments.length; ++i) {
+                segment.allPrevSegments[i].allNextSegments.push(segment);
+            }
+        }
+    }
+
+    /**
+     * Marks a previous segment as looped.
+     * @param {CodePathSegment} segment A segment.
+     * @param {CodePathSegment} prevSegment A previous segment to mark.
+     * @returns {void}
+     */
+    static markPrevSegmentAsLooped(segment, prevSegment) {
+        segment.internal.loopedPrevSegments.push(prevSegment);
+    }
+
+    /**
+     * Creates a new array based on an array of segments. If any segment in the
+     * array is unused, then it is replaced by all of its previous segments.
+     * All used segments are returned as-is without replacement.
+     * @param {CodePathSegment[]} segments The array of segments to flatten.
+     * @returns {CodePathSegment[]} The flattened array.
+     */
+    static flattenUnusedSegments(segments) {
+        const done = new Set();
+
+        for (let i = 0; i < segments.length; ++i) {
+            const segment = segments[i];
+
+            // Ignores duplicated.
+            if (done.has(segment)) {
+                continue;
+            }
+
+            // Use previous segments if unused.
+            if (!segment.internal.used) {
+                for (let j = 0; j < segment.allPrevSegments.length; ++j) {
+                    const prevSegment = segment.allPrevSegments[j];
+
+                    if (!done.has(prevSegment)) {
+                        done.add(prevSegment);
+                    }
+                }
+            } else {
+                done.add(segment);
+            }
+        }
+
+        return [...done];
+    }
+}
+
+module.exports = CodePathSegment;

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/code-path.js

@@ -0,0 +1,342 @@
+/**
+ * @fileoverview A class of the code path.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const CodePathState = require("./code-path-state");
+const IdGenerator = require("./id-generator");
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * A code path.
+ */
+class CodePath {
+
+    /**
+     * Creates a new instance.
+     * @param {Object} options Options for the function (see below).
+     * @param {string} options.id An identifier.
+     * @param {string} options.origin The type of code path origin.
+     * @param {CodePath|null} options.upper The code path of the upper function scope.
+     * @param {Function} options.onLooped A callback function to notify looping.
+     */
+    constructor({ id, origin, upper, onLooped }) {
+
+        /**
+         * The identifier of this code path.
+         * Rules use it to store additional information of each rule.
+         * @type {string}
+         */
+        this.id = id;
+
+        /**
+         * The reason that this code path was started. May be "program",
+         * "function", "class-field-initializer", or "class-static-block".
+         * @type {string}
+         */
+        this.origin = origin;
+
+        /**
+         * The code path of the upper function scope.
+         * @type {CodePath|null}
+         */
+        this.upper = upper;
+
+        /**
+         * The code paths of nested function scopes.
+         * @type {CodePath[]}
+         */
+        this.childCodePaths = [];
+
+        // Initializes internal state.
+        Object.defineProperty(
+            this,
+            "internal",
+            { value: new CodePathState(new IdGenerator(`${id}_`), onLooped) }
+        );
+
+        // Adds this into `childCodePaths` of `upper`.
+        if (upper) {
+            upper.childCodePaths.push(this);
+        }
+    }
+
+    /**
+     * Gets the state of a given code path.
+     * @param {CodePath} codePath A code path to get.
+     * @returns {CodePathState} The state of the code path.
+     */
+    static getState(codePath) {
+        return codePath.internal;
+    }
+
+    /**
+     * The initial code path segment. This is the segment that is at the head
+     * of the code path.
+     * This is a passthrough to the underlying `CodePathState`.
+     * @type {CodePathSegment}
+     */
+    get initialSegment() {
+        return this.internal.initialSegment;
+    }
+
+    /**
+     * Final code path segments. These are the terminal (tail) segments in the
+     * code path, which is the combination of `returnedSegments` and `thrownSegments`.
+     * All segments in this array are reachable.
+     * This is a passthrough to the underlying `CodePathState`.
+     * @type {CodePathSegment[]}
+     */
+    get finalSegments() {
+        return this.internal.finalSegments;
+    }
+
+    /**
+     * Final code path segments that represent normal completion of the code path.
+     * For functions, this means both explicit `return` statements and implicit returns,
+     * such as the last reachable segment in a function that does not have an
+     * explicit `return` as this implicitly returns `undefined`. For scripts,
+     * modules, class field initializers, and class static blocks, this means
+     * all lines of code have been executed.
+     * These segments are also present in `finalSegments`.
+     * This is a passthrough to the underlying `CodePathState`.
+     * @type {CodePathSegment[]}
+     */
+    get returnedSegments() {
+        return this.internal.returnedForkContext;
+    }
+
+    /**
+     * Final code path segments that represent `throw` statements.
+     * This is a passthrough to the underlying `CodePathState`.
+     * These segments are also present in `finalSegments`.
+     * @type {CodePathSegment[]}
+     */
+    get thrownSegments() {
+        return this.internal.thrownForkContext;
+    }
+
+    /**
+     * Tracks the traversal of the code path through each segment. This array
+     * starts empty and segments are added or removed as the code path is
+     * traversed. This array always ends up empty at the end of a code path
+     * traversal. The `CodePathState` uses this to track its progress through
+     * the code path.
+     * This is a passthrough to the underlying `CodePathState`.
+     * @type {CodePathSegment[]}
+     * @deprecated
+     */
+    get currentSegments() {
+        return this.internal.currentSegments;
+    }
+
+    /**
+     * Traverses all segments in this code path.
+     *
+     *     codePath.traverseSegments((segment, controller) => {
+     *         // do something.
+     *     });
+     *
+     * This method enumerates segments in order from the head.
+     *
+     * The `controller` argument has two methods:
+     *
+     * - `skip()` - skips the following segments in this branch
+     * - `break()` - skips all following segments in the traversal
+     *
+     * A note on the parameters: the `options` argument is optional. This means
+     * the first argument might be an options object or the callback function.
+     * @param {Object} [optionsOrCallback] Optional first and last segments to traverse.
+     * @param {CodePathSegment} [optionsOrCallback.first] The first segment to traverse.
+     * @param {CodePathSegment} [optionsOrCallback.last] The last segment to traverse.
+     * @param {Function} callback A callback function.
+     * @returns {void}
+     */
+    traverseSegments(optionsOrCallback, callback) {
+
+        // normalize the arguments into a callback and options
+        let resolvedOptions;
+        let resolvedCallback;
+
+        if (typeof optionsOrCallback === "function") {
+            resolvedCallback = optionsOrCallback;
+            resolvedOptions = {};
+        } else {
+            resolvedOptions = optionsOrCallback || {};
+            resolvedCallback = callback;
+        }
+
+        // determine where to start traversing from based on the options
+        const startSegment = resolvedOptions.first || this.internal.initialSegment;
+        const lastSegment = resolvedOptions.last;
+
+        // set up initial location information
+        let record = null;
+        let index = 0;
+        let end = 0;
+        let segment = null;
+
+        // segments that have already been visited during traversal
+        const visited = new Set();
+
+        // tracks the traversal steps
+        const stack = [[startSegment, 0]];
+
+        // tracks the last skipped segment during traversal
+        let skippedSegment = null;
+
+        // indicates if we exited early from the traversal
+        let broken = false;
+
+        /**
+         * Maintains traversal state.
+         */
+        const controller = {
+
+            /**
+             * Skip the following segments in this branch.
+             * @returns {void}
+             */
+            skip() {
+                if (stack.length <= 1) {
+                    broken = true;
+                } else {
+                    skippedSegment = stack[stack.length - 2][0];
+                }
+            },
+
+            /**
+             * Stop traversal completely - do not traverse to any
+             * other segments.
+             * @returns {void}
+             */
+            break() {
+                broken = true;
+            }
+        };
+
+        /**
+         * Checks if a given previous segment has been visited.
+         * @param {CodePathSegment} prevSegment A previous segment to check.
+         * @returns {boolean} `true` if the segment has been visited.
+         */
+        function isVisited(prevSegment) {
+            return (
+                visited.has(prevSegment) ||
+                segment.isLoopedPrevSegment(prevSegment)
+            );
+        }
+
+        // the traversal
+        while (stack.length > 0) {
+
+            /*
+             * This isn't a pure stack. We use the top record all the time
+             * but don't always pop it off. The record is popped only if
+             * one of the following is true:
+             *
+             * 1) We have already visited the segment.
+             * 2) We have not visited *all* of the previous segments.
+             * 3) We have traversed past the available next segments.
+             *
+             * Otherwise, we just read the value and sometimes modify the
+             * record as we traverse.
+             */
+            record = stack[stack.length - 1];
+            segment = record[0];
+            index = record[1];
+
+            if (index === 0) {
+
+                // Skip if this segment has been visited already.
+                if (visited.has(segment)) {
+                    stack.pop();
+                    continue;
+                }
+
+                // Skip if all previous segments have not been visited.
+                if (segment !== startSegment &&
+                    segment.prevSegments.length > 0 &&
+                    !segment.prevSegments.every(isVisited)
+                ) {
+                    stack.pop();
+                    continue;
+                }
+
+                // Reset the skipping flag if all branches have been skipped.
+                if (skippedSegment && segment.prevSegments.includes(skippedSegment)) {
+                    skippedSegment = null;
+                }
+                visited.add(segment);
+
+                /*
+                 * If the most recent segment hasn't been skipped, then we call
+                 * the callback, passing in the segment and the controller.
+                 */
+                if (!skippedSegment) {
+                    resolvedCallback.call(this, segment, controller);
+
+                    // exit if we're at the last segment
+                    if (segment === lastSegment) {
+                        controller.skip();
+                    }
+
+                    /*
+                     * If the previous statement was executed, or if the callback
+                     * called a method on the controller, we might need to exit the
+                     * loop, so check for that and break accordingly.
+                     */
+                    if (broken) {
+                        break;
+                    }
+                }
+            }
+
+            // Update the stack.
+            end = segment.nextSegments.length - 1;
+            if (index < end) {
+
+                /*
+                 * If we haven't yet visited all of the next segments, update
+                 * the current top record on the stack to the next index to visit
+                 * and then push a record for the current segment on top.
+                 *
+                 * Setting the current top record's index lets us know how many
+                 * times we've been here and ensures that the segment won't be
+                 * reprocessed (because we only process segments with an index
+                 * of 0).
+                 */
+                record[1] += 1;
+                stack.push([segment.nextSegments[index], 0]);
+            } else if (index === end) {
+
+                /*
+                 * If we are at the last next segment, then reset the top record
+                 * in the stack to next segment and set its index to 0 so it will
+                 * be processed next.
+                 */
+                record[0] = segment.nextSegments[index];
+                record[1] = 0;
+            } else {
+
+                /*
+                 * If index > end, that means we have no more segments that need
+                 * processing. So, we pop that record off of the stack in order to
+                 * continue traversing at the next level up.
+                 */
+                stack.pop();
+            }
+        }
+    }
+}
+
+module.exports = CodePath;

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/debug-helpers.js

@@ -0,0 +1,203 @@
+/**
+ * @fileoverview Helpers to debug for code path analysis.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const debug = require("debug")("eslint:code-path");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Gets id of a given segment.
+ * @param {CodePathSegment} segment A segment to get.
+ * @returns {string} Id of the segment.
+ */
+/* c8 ignore next */
+function getId(segment) { // eslint-disable-line jsdoc/require-jsdoc -- Ignoring
+    return segment.id + (segment.reachable ? "" : "!");
+}
+
+/**
+ * Get string for the given node and operation.
+ * @param {ASTNode} node The node to convert.
+ * @param {"enter" | "exit" | undefined} label The operation label.
+ * @returns {string} The string representation.
+ */
+function nodeToString(node, label) {
+    const suffix = label ? `:${label}` : "";
+
+    switch (node.type) {
+        case "Identifier": return `${node.type}${suffix} (${node.name})`;
+        case "Literal": return `${node.type}${suffix} (${node.value})`;
+        default: return `${node.type}${suffix}`;
+    }
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = {
+
+    /**
+     * A flag that debug dumping is enabled or not.
+     * @type {boolean}
+     */
+    enabled: debug.enabled,
+
+    /**
+     * Dumps given objects.
+     * @param {...any} args objects to dump.
+     * @returns {void}
+     */
+    dump: debug,
+
+    /**
+     * Dumps the current analyzing state.
+     * @param {ASTNode} node A node to dump.
+     * @param {CodePathState} state A state to dump.
+     * @param {boolean} leaving A flag whether or not it's leaving
+     * @returns {void}
+     */
+    dumpState: !debug.enabled ? debug : /* c8 ignore next */ function(node, state, leaving) {
+        for (let i = 0; i < state.currentSegments.length; ++i) {
+            const segInternal = state.currentSegments[i].internal;
+
+            if (leaving) {
+                const last = segInternal.nodes.length - 1;
+
+                if (last >= 0 && segInternal.nodes[last] === nodeToString(node, "enter")) {
+                    segInternal.nodes[last] = nodeToString(node, void 0);
+                } else {
+                    segInternal.nodes.push(nodeToString(node, "exit"));
+                }
+            } else {
+                segInternal.nodes.push(nodeToString(node, "enter"));
+            }
+        }
+
+        debug([
+            `${state.currentSegments.map(getId).join(",")})`,
+            `${node.type}${leaving ? ":exit" : ""}`
+        ].join(" "));
+    },
+
+    /**
+     * Dumps a DOT code of a given code path.
+     * The DOT code can be visualized with Graphvis.
+     * @param {CodePath} codePath A code path to dump.
+     * @returns {void}
+     * @see http://www.graphviz.org
+     * @see http://www.webgraphviz.com
+     */
+    dumpDot: !debug.enabled ? debug : /* c8 ignore next */ function(codePath) {
+        let text =
+            "\n" +
+            "digraph {\n" +
+            "node[shape=box,style=\"rounded,filled\",fillcolor=white];\n" +
+            "initial[label=\"\",shape=circle,style=filled,fillcolor=black,width=0.25,height=0.25];\n";
+
+        if (codePath.returnedSegments.length > 0) {
+            text += "final[label=\"\",shape=doublecircle,style=filled,fillcolor=black,width=0.25,height=0.25];\n";
+        }
+        if (codePath.thrownSegments.length > 0) {
+            text += "thrown[label=\"✘\",shape=circle,width=0.3,height=0.3,fixedsize=true];\n";
+        }
+
+        const traceMap = Object.create(null);
+        const arrows = this.makeDotArrows(codePath, traceMap);
+
+        for (const id in traceMap) { // eslint-disable-line guard-for-in -- Want ability to traverse prototype
+            const segment = traceMap[id];
+
+            text += `${id}[`;
+
+            if (segment.reachable) {
+                text += "label=\"";
+            } else {
+                text += "style=\"rounded,dashed,filled\",fillcolor=\"#FF9800\",label=\"<<unreachable>>\\n";
+            }
+
+            if (segment.internal.nodes.length > 0) {
+                text += segment.internal.nodes.join("\\n");
+            } else {
+                text += "????";
+            }
+
+            text += "\"];\n";
+        }
+
+        text += `${arrows}\n`;
+        text += "}";
+        debug("DOT", text);
+    },
+
+    /**
+     * Makes a DOT code of a given code path.
+     * The DOT code can be visualized with Graphvis.
+     * @param {CodePath} codePath A code path to make DOT.
+     * @param {Object} traceMap Optional. A map to check whether or not segments had been done.
+     * @returns {string} A DOT code of the code path.
+     */
+    makeDotArrows(codePath, traceMap) {
+        const stack = [[codePath.initialSegment, 0]];
+        const done = traceMap || Object.create(null);
+        let lastId = codePath.initialSegment.id;
+        let text = `initial->${codePath.initialSegment.id}`;
+
+        while (stack.length > 0) {
+            const item = stack.pop();
+            const segment = item[0];
+            const index = item[1];
+
+            if (done[segment.id] && index === 0) {
+                continue;
+            }
+            done[segment.id] = segment;
+
+            const nextSegment = segment.allNextSegments[index];
+
+            if (!nextSegment) {
+                continue;
+            }
+
+            if (lastId === segment.id) {
+                text += `->${nextSegment.id}`;
+            } else {
+                text += `;\n${segment.id}->${nextSegment.id}`;
+            }
+            lastId = nextSegment.id;
+
+            stack.unshift([segment, 1 + index]);
+            stack.push([nextSegment, 0]);
+        }
+
+        codePath.returnedSegments.forEach(finalSegment => {
+            if (lastId === finalSegment.id) {
+                text += "->final";
+            } else {
+                text += `;\n${finalSegment.id}->final`;
+            }
+            lastId = null;
+        });
+
+        codePath.thrownSegments.forEach(finalSegment => {
+            if (lastId === finalSegment.id) {
+                text += "->thrown";
+            } else {
+                text += `;\n${finalSegment.id}->thrown`;
+            }
+            lastId = null;
+        });
+
+        return `${text};`;
+    }
+};

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/fork-context.js

@@ -0,0 +1,349 @@
+/**
+ * @fileoverview A class to operate forking.
+ *
+ * This is state of forking.
+ * This has a fork list and manages it.
+ *
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const assert = require("assert"),
+    CodePathSegment = require("./code-path-segment");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Determines whether or not a given segment is reachable.
+ * @param {CodePathSegment} segment The segment to check.
+ * @returns {boolean} `true` if the segment is reachable.
+ */
+function isReachable(segment) {
+    return segment.reachable;
+}
+
+/**
+ * Creates a new segment for each fork in the given context and appends it
+ * to the end of the specified range of segments. Ultimately, this ends up calling
+ * `new CodePathSegment()` for each of the forks using the `create` argument
+ * as a wrapper around special behavior.
+ *
+ * The `startIndex` and `endIndex` arguments specify a range of segments in
+ * `context` that should become `allPrevSegments` for the newly created
+ * `CodePathSegment` objects.
+ *
+ * When `context.segmentsList` is `[[a, b], [c, d], [e, f]]`, `begin` is `0`, and
+ * `end` is `-1`, this creates two new segments, `[g, h]`. This `g` is appended to
+ * the end of the path from `a`, `c`, and `e`. This `h` is appended to the end of
+ * `b`, `d`, and `f`.
+ * @param {ForkContext} context An instance from which the previous segments
+ *      will be obtained.
+ * @param {number} startIndex The index of the first segment in the context
+ *      that should be specified as previous segments for the newly created segments.
+ * @param {number} endIndex The index of the last segment in the context
+ *      that should be specified as previous segments for the newly created segments.
+ * @param {Function} create A function that creates new `CodePathSegment`
+ *      instances in a particular way. See the `CodePathSegment.new*` methods.
+ * @returns {Array<CodePathSegment>} An array of the newly-created segments.
+ */
+function createSegments(context, startIndex, endIndex, create) {
+
+    /** @type {Array<Array<CodePathSegment>>} */
+    const list = context.segmentsList;
+
+    /*
+     * Both `startIndex` and `endIndex` work the same way: if the number is zero
+     * or more, then the number is used as-is. If the number is negative,
+     * then that number is added to the length of the segments list to
+     * determine the index to use. That means -1 for either argument
+     * is the last element, -2 is the second to last, and so on.
+     *
+     * So if `startIndex` is 0, `endIndex` is -1, and `list.length` is 3, the
+     * effective `startIndex` is 0 and the effective `endIndex` is 2, so this function
+     * will include items at indices 0, 1, and 2.
+     *
+     * Therefore, if `startIndex` is -1 and `endIndex` is -1, that means we'll only
+     * be using the last segment in `list`.
+     */
+    const normalizedBegin = startIndex >= 0 ? startIndex : list.length + startIndex;
+    const normalizedEnd = endIndex >= 0 ? endIndex : list.length + endIndex;
+
+    /** @type {Array<CodePathSegment>} */
+    const segments = [];
+
+    for (let i = 0; i < context.count; ++i) {
+
+        // this is passed into `new CodePathSegment` to add to code path.
+        const allPrevSegments = [];
+
+        for (let j = normalizedBegin; j <= normalizedEnd; ++j) {
+            allPrevSegments.push(list[j][i]);
+        }
+
+        // note: `create` is just a wrapper that augments `new CodePathSegment`.
+        segments.push(create(context.idGenerator.next(), allPrevSegments));
+    }
+
+    return segments;
+}
+
+/**
+ * Inside of a `finally` block we end up with two parallel paths. If the code path
+ * exits by a control statement (such as `break` or `continue`) from the `finally`
+ * block, then we need to merge the remaining parallel paths back into one.
+ * @param {ForkContext} context The fork context to work on.
+ * @param {Array<CodePathSegment>} segments Segments to merge.
+ * @returns {Array<CodePathSegment>} The merged segments.
+ */
+function mergeExtraSegments(context, segments) {
+    let currentSegments = segments;
+
+    /*
+     * We need to ensure that the array returned from this function contains no more
+     * than the number of segments that the context allows. `context.count` indicates
+     * how many items should be in the returned array to ensure that the new segment
+     * entries will line up with the already existing segment entries.
+     */
+    while (currentSegments.length > context.count) {
+        const merged = [];
+
+        /*
+         * Because `context.count` is a factor of 2 inside of a `finally` block,
+         * we can divide the segment count by 2 to merge the paths together.
+         * This loops through each segment in the list and creates a new `CodePathSegment`
+         * that has the segment and the segment two slots away as previous segments.
+         *
+         * If `currentSegments` is [a,b,c,d], this will create new segments e and f, such
+         * that:
+         *
+         * When `i` is 0:
+         * a->e
+         * c->e
+         *
+         * When `i` is 1:
+         * b->f
+         * d->f
+         */
+        for (let i = 0, length = Math.floor(currentSegments.length / 2); i < length; ++i) {
+            merged.push(CodePathSegment.newNext(
+                context.idGenerator.next(),
+                [currentSegments[i], currentSegments[i + length]]
+            ));
+        }
+
+        /*
+         * Go through the loop condition one more time to see if we have the
+         * number of segments for the context. If not, we'll keep merging paths
+         * of the merged segments until we get there.
+         */
+        currentSegments = merged;
+    }
+
+    return currentSegments;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Manages the forking of code paths.
+ */
+class ForkContext {
+
+    /**
+     * Creates a new instance.
+     * @param {IdGenerator} idGenerator An identifier generator for segments.
+     * @param {ForkContext|null} upper The preceding fork context.
+     * @param {number} count The number of parallel segments in each element
+     *      of `segmentsList`.
+     */
+    constructor(idGenerator, upper, count) {
+
+        /**
+         * The ID generator that will generate segment IDs for any new
+         * segments that are created.
+         * @type {IdGenerator}
+         */
+        this.idGenerator = idGenerator;
+
+        /**
+         * The preceding fork context.
+         * @type {ForkContext|null}
+         */
+        this.upper = upper;
+
+        /**
+         * The number of elements in each element of `segmentsList`. In most
+         * cases, this is 1 but can be 2 when there is a `finally` present,
+         * which forks the code path outside of normal flow. In the case of nested
+         * `finally` blocks, this can be a multiple of 2.
+         * @type {number}
+         */
+        this.count = count;
+
+        /**
+         * The segments within this context. Each element in this array has
+         * `count` elements that represent one step in each fork. For example,
+         * when `segmentsList` is `[[a, b], [c, d], [e, f]]`, there is one path
+         * a->c->e and one path b->d->f, and `count` is 2 because each element
+         * is an array with two elements.
+         * @type {Array<Array<CodePathSegment>>}
+         */
+        this.segmentsList = [];
+    }
+
+    /**
+     * The segments that begin this fork context.
+     * @type {Array<CodePathSegment>}
+     */
+    get head() {
+        const list = this.segmentsList;
+
+        return list.length === 0 ? [] : list[list.length - 1];
+    }
+
+    /**
+     * Indicates if the context contains no segments.
+     * @type {boolean}
+     */
+    get empty() {
+        return this.segmentsList.length === 0;
+    }
+
+    /**
+     * Indicates if there are any segments that are reachable.
+     * @type {boolean}
+     */
+    get reachable() {
+        const segments = this.head;
+
+        return segments.length > 0 && segments.some(isReachable);
+    }
+
+    /**
+     * Creates new segments in this context and appends them to the end of the
+     * already existing `CodePathSegment`s specified by `startIndex` and
+     * `endIndex`.
+     * @param {number} startIndex The index of the first segment in the context
+     *      that should be specified as previous segments for the newly created segments.
+     * @param {number} endIndex The index of the last segment in the context
+     *      that should be specified as previous segments for the newly created segments.
+     * @returns {Array<CodePathSegment>} An array of the newly created segments.
+     */
+    makeNext(startIndex, endIndex) {
+        return createSegments(this, startIndex, endIndex, CodePathSegment.newNext);
+    }
+
+    /**
+     * Creates new unreachable segments in this context and appends them to the end of the
+     * already existing `CodePathSegment`s specified by `startIndex` and
+     * `endIndex`.
+     * @param {number} startIndex The index of the first segment in the context
+     *      that should be specified as previous segments for the newly created segments.
+     * @param {number} endIndex The index of the last segment in the context
+     *      that should be specified as previous segments for the newly created segments.
+     * @returns {Array<CodePathSegment>} An array of the newly created segments.
+     */
+    makeUnreachable(startIndex, endIndex) {
+        return createSegments(this, startIndex, endIndex, CodePathSegment.newUnreachable);
+    }
+
+    /**
+     * Creates new segments in this context and does not append them to the end
+     *  of the already existing `CodePathSegment`s specified by `startIndex` and
+     * `endIndex`. The `startIndex` and `endIndex` are only used to determine if
+     * the new segments should be reachable. If any of the segments in this range
+     * are reachable then the new segments are also reachable; otherwise, the new
+     * segments are unreachable.
+     * @param {number} startIndex The index of the first segment in the context
+     *      that should be considered for reachability.
+     * @param {number} endIndex The index of the last segment in the context
+     *      that should be considered for reachability.
+     * @returns {Array<CodePathSegment>} An array of the newly created segments.
+     */
+    makeDisconnected(startIndex, endIndex) {
+        return createSegments(this, startIndex, endIndex, CodePathSegment.newDisconnected);
+    }
+
+    /**
+     * Adds segments to the head of this context.
+     * @param {Array<CodePathSegment>} segments The segments to add.
+     * @returns {void}
+     */
+    add(segments) {
+        assert(segments.length >= this.count, `${segments.length} >= ${this.count}`);
+        this.segmentsList.push(mergeExtraSegments(this, segments));
+    }
+
+    /**
+     * Replaces the head segments with the given segments.
+     * The current head segments are removed.
+     * @param {Array<CodePathSegment>} replacementHeadSegments The new head segments.
+     * @returns {void}
+     */
+    replaceHead(replacementHeadSegments) {
+        assert(
+            replacementHeadSegments.length >= this.count,
+            `${replacementHeadSegments.length} >= ${this.count}`
+        );
+        this.segmentsList.splice(-1, 1, mergeExtraSegments(this, replacementHeadSegments));
+    }
+
+    /**
+     * Adds all segments of a given fork context into this context.
+     * @param {ForkContext} otherForkContext The fork context to add from.
+     * @returns {void}
+     */
+    addAll(otherForkContext) {
+        assert(otherForkContext.count === this.count);
+        this.segmentsList.push(...otherForkContext.segmentsList);
+    }
+
+    /**
+     * Clears all segments in this context.
+     * @returns {void}
+     */
+    clear() {
+        this.segmentsList = [];
+    }
+
+    /**
+     * Creates a new root context, meaning that there are no parent
+     * fork contexts.
+     * @param {IdGenerator} idGenerator An identifier generator for segments.
+     * @returns {ForkContext} New fork context.
+     */
+    static newRoot(idGenerator) {
+        const context = new ForkContext(idGenerator, null, 1);
+
+        context.add([CodePathSegment.newRoot(idGenerator.next())]);
+
+        return context;
+    }
+
+    /**
+     * Creates an empty fork context preceded by a given context.
+     * @param {ForkContext} parentContext The parent fork context.
+     * @param {boolean} shouldForkLeavingPath Indicates that we are inside of
+     *      a `finally` block and should therefore fork the path that leaves
+     *      `finally`.
+     * @returns {ForkContext} New fork context.
+     */
+    static newEmpty(parentContext, shouldForkLeavingPath) {
+        return new ForkContext(
+            parentContext.idGenerator,
+            parentContext,
+            (shouldForkLeavingPath ? 2 : 1) * parentContext.count
+        );
+    }
+}
+
+module.exports = ForkContext;

qwen/nodejs/node_modules/eslint/lib/linter/code-path-analysis/id-generator.js

@@ -0,0 +1,45 @@
+/**
+ * @fileoverview A class of identifiers generator for code path segments.
+ *
+ * Each rule uses the identifier of code path segments to store additional
+ * information of the code path.
+ *
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * A generator for unique ids.
+ */
+class IdGenerator {
+
+    /**
+     * @param {string} prefix Optional. A prefix of generated ids.
+     */
+    constructor(prefix) {
+        this.prefix = String(prefix);
+        this.n = 0;
+    }
+
+    /**
+     * Generates id.
+     * @returns {string} A generated id.
+     */
+    next() {
+        this.n = 1 + this.n | 0;
+
+        /* c8 ignore start */
+        if (this.n < 0) {
+            this.n = 1;
+        }/* c8 ignore stop */
+
+        return this.prefix + this.n;
+    }
+}
+
+module.exports = IdGenerator;

qwen/nodejs/node_modules/eslint/lib/linter/config-comment-parser.js

@@ -0,0 +1,185 @@
+/**
+ * @fileoverview Config Comment Parser
+ * @author Nicholas C. Zakas
+ */
+
+/* eslint class-methods-use-this: off -- Methods desired on instance */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const levn = require("levn"),
+    {
+        Legacy: {
+            ConfigOps
+        }
+    } = require("@eslint/eslintrc/universal"),
+    {
+        directivesPattern
+    } = require("../shared/directives");
+
+const debug = require("debug")("eslint:config-comment-parser");
+
+//------------------------------------------------------------------------------
+// Typedefs
+//------------------------------------------------------------------------------
+
+/** @typedef {import("../shared/types").LintMessage} LintMessage */
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Object to parse ESLint configuration comments inside JavaScript files.
+ * @name ConfigCommentParser
+ */
+module.exports = class ConfigCommentParser {
+
+    /**
+     * Parses a list of "name:string_value" or/and "name" options divided by comma or
+     * whitespace. Used for "global" and "exported" comments.
+     * @param {string} string The string to parse.
+     * @param {Comment} comment The comment node which has the string.
+     * @returns {Object} Result map object of names and string values, or null values if no value was provided
+     */
+    parseStringConfig(string, comment) {
+        debug("Parsing String config");
+
+        const items = {};
+
+        // Collapse whitespace around `:` and `,` to make parsing easier
+        const trimmedString = string.replace(/\s*([:,])\s*/gu, "$1");
+
+        trimmedString.split(/\s|,+/u).forEach(name => {
+            if (!name) {
+                return;
+            }
+
+            // value defaults to null (if not provided), e.g: "foo" => ["foo", null]
+            const [key, value = null] = name.split(":");
+
+            items[key] = { value, comment };
+        });
+        return items;
+    }
+
+    /**
+     * Parses a JSON-like config.
+     * @param {string} string The string to parse.
+     * @param {Object} location Start line and column of comments for potential error message.
+     * @returns {({success: true, config: Object}|{success: false, error: LintMessage})} Result map object
+     */
+    parseJsonConfig(string, location) {
+        debug("Parsing JSON config");
+
+        let items = {};
+
+        // Parses a JSON-like comment by the same way as parsing CLI option.
+        try {
+            items = levn.parse("Object", string) || {};
+
+            // Some tests say that it should ignore invalid comments such as `/*eslint no-alert:abc*/`.
+            // Also, commaless notations have invalid severity:
+            //     "no-alert: 2 no-console: 2" --> {"no-alert": "2 no-console: 2"}
+            // Should ignore that case as well.
+            if (ConfigOps.isEverySeverityValid(items)) {
+                return {
+                    success: true,
+                    config: items
+                };
+            }
+        } catch {
+
+            debug("Levn parsing failed; falling back to manual parsing.");
+
+            // ignore to parse the string by a fallback.
+        }
+
+        /*
+         * Optionator cannot parse commaless notations.
+         * But we are supporting that. So this is a fallback for that.
+         */
+        items = {};
+        const normalizedString = string.replace(/([-a-zA-Z0-9/]+):/gu, "\"$1\":").replace(/(\]|[0-9])\s+(?=")/u, "$1,");
+
+        try {
+            items = JSON.parse(`{${normalizedString}}`);
+        } catch (ex) {
+            debug("Manual parsing failed.");
+
+            return {
+                success: false,
+                error: {
+                    ruleId: null,
+                    fatal: true,
+                    severity: 2,
+                    message: `Failed to parse JSON from '${normalizedString}': ${ex.message}`,
+                    line: location.start.line,
+                    column: location.start.column + 1,
+                    nodeType: null
+                }
+            };
+
+        }
+
+        return {
+            success: true,
+            config: items
+        };
+    }
+
+    /**
+     * Parses a config of values separated by comma.
+     * @param {string} string The string to parse.
+     * @returns {Object} Result map of values and true values
+     */
+    parseListConfig(string) {
+        debug("Parsing list config");
+
+        const items = {};
+
+        string.split(",").forEach(name => {
+            const trimmedName = name.trim().replace(/^(?<quote>['"]?)(?<ruleId>.*)\k<quote>$/us, "$<ruleId>");
+
+            if (trimmedName) {
+                items[trimmedName] = true;
+            }
+        });
+        return items;
+    }
+
+    /**
+     * Extract the directive and the justification from a given directive comment and trim them.
+     * @param {string} value The comment text to extract.
+     * @returns {{directivePart: string, justificationPart: string}} The extracted directive and justification.
+     */
+    extractDirectiveComment(value) {
+        const match = /\s-{2,}\s/u.exec(value);
+
+        if (!match) {
+            return { directivePart: value.trim(), justificationPart: "" };
+        }
+
+        const directive = value.slice(0, match.index).trim();
+        const justification = value.slice(match.index + match[0].length).trim();
+
+        return { directivePart: directive, justificationPart: justification };
+    }
+
+    /**
+     * Parses a directive comment into directive text and value.
+     * @param {Comment} comment The comment node with the directive to be parsed.
+     * @returns {{directiveText: string, directiveValue: string}} The directive text and value.
+     */
+    parseDirective(comment) {
+        const { directivePart } = this.extractDirectiveComment(comment.value);
+        const match = directivesPattern.exec(directivePart);
+        const directiveText = match[1];
+        const directiveValue = directivePart.slice(match.index + directiveText.length);
+
+        return { directiveText, directiveValue };
+    }
+};

qwen/nodejs/node_modules/eslint/lib/linter/index.js

@@ -0,0 +1,13 @@
+"use strict";
+
+const { Linter } = require("./linter");
+const interpolate = require("./interpolate");
+const SourceCodeFixer = require("./source-code-fixer");
+
+module.exports = {
+    Linter,
+
+    // For testers.
+    SourceCodeFixer,
+    interpolate
+};

qwen/nodejs/node_modules/eslint/lib/linter/interpolate.js

@@ -0,0 +1,28 @@
+/**
+ * @fileoverview Interpolate keys from an object into a string with {{ }} markers.
+ * @author Jed Fox
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = (text, data) => {
+    if (!data) {
+        return text;
+    }
+
+    // Substitution content for any {{ }} markers.
+    return text.replace(/\{\{([^{}]+?)\}\}/gu, (fullMatch, termWithWhitespace) => {
+        const term = termWithWhitespace.trim();
+
+        if (term in data) {
+            return data[term];
+        }
+
+        // Preserve old behavior: If parameter name not provided, don't replace it.
+        return fullMatch;
+    });
+};

qwen/nodejs/node_modules/eslint/lib/linter/node-event-generator.js

@@ -0,0 +1,354 @@
+/**
+ * @fileoverview The event generator for AST nodes.
+ * @author Toru Nagashima
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const esquery = require("esquery");
+
+//------------------------------------------------------------------------------
+// Typedefs
+//------------------------------------------------------------------------------
+
+/**
+ * An object describing an AST selector
+ * @typedef {Object} ASTSelector
+ * @property {string} rawSelector The string that was parsed into this selector
+ * @property {boolean} isExit `true` if this should be emitted when exiting the node rather than when entering
+ * @property {Object} parsedSelector An object (from esquery) describing the matching behavior of the selector
+ * @property {string[]|null} listenerTypes A list of node types that could possibly cause the selector to match,
+ * or `null` if all node types could cause a match
+ * @property {number} attributeCount The total number of classes, pseudo-classes, and attribute queries in this selector
+ * @property {number} identifierCount The total number of identifier queries in this selector
+ */
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Computes the union of one or more arrays
+ * @param {...any[]} arrays One or more arrays to union
+ * @returns {any[]} The union of the input arrays
+ */
+function union(...arrays) {
+    return [...new Set(arrays.flat())];
+}
+
+/**
+ * Computes the intersection of one or more arrays
+ * @param {...any[]} arrays One or more arrays to intersect
+ * @returns {any[]} The intersection of the input arrays
+ */
+function intersection(...arrays) {
+    if (arrays.length === 0) {
+        return [];
+    }
+
+    let result = [...new Set(arrays[0])];
+
+    for (const array of arrays.slice(1)) {
+        result = result.filter(x => array.includes(x));
+    }
+    return result;
+}
+
+/**
+ * Gets the possible types of a selector
+ * @param {Object} parsedSelector An object (from esquery) describing the matching behavior of the selector
+ * @returns {string[]|null} The node types that could possibly trigger this selector, or `null` if all node types could trigger it
+ */
+function getPossibleTypes(parsedSelector) {
+    switch (parsedSelector.type) {
+        case "identifier":
+            return [parsedSelector.value];
+
+        case "matches": {
+            const typesForComponents = parsedSelector.selectors.map(getPossibleTypes);
+
+            if (typesForComponents.every(Boolean)) {
+                return union(...typesForComponents);
+            }
+            return null;
+        }
+
+        case "compound": {
+            const typesForComponents = parsedSelector.selectors.map(getPossibleTypes).filter(typesForComponent => typesForComponent);
+
+            // If all of the components could match any type, then the compound could also match any type.
+            if (!typesForComponents.length) {
+                return null;
+            }
+
+            /*
+             * If at least one of the components could only match a particular type, the compound could only match
+             * the intersection of those types.
+             */
+            return intersection(...typesForComponents);
+        }
+
+        case "child":
+        case "descendant":
+        case "sibling":
+        case "adjacent":
+            return getPossibleTypes(parsedSelector.right);
+
+        case "class":
+            if (parsedSelector.name === "function") {
+                return ["FunctionDeclaration", "FunctionExpression", "ArrowFunctionExpression"];
+            }
+
+            return null;
+
+        default:
+            return null;
+
+    }
+}
+
+/**
+ * Counts the number of class, pseudo-class, and attribute queries in this selector
+ * @param {Object} parsedSelector An object (from esquery) describing the selector's matching behavior
+ * @returns {number} The number of class, pseudo-class, and attribute queries in this selector
+ */
+function countClassAttributes(parsedSelector) {
+    switch (parsedSelector.type) {
+        case "child":
+        case "descendant":
+        case "sibling":
+        case "adjacent":
+            return countClassAttributes(parsedSelector.left) + countClassAttributes(parsedSelector.right);
+
+        case "compound":
+        case "not":
+        case "matches":
+            return parsedSelector.selectors.reduce((sum, childSelector) => sum + countClassAttributes(childSelector), 0);
+
+        case "attribute":
+        case "field":
+        case "nth-child":
+        case "nth-last-child":
+            return 1;
+
+        default:
+            return 0;
+    }
+}
+
+/**
+ * Counts the number of identifier queries in this selector
+ * @param {Object} parsedSelector An object (from esquery) describing the selector's matching behavior
+ * @returns {number} The number of identifier queries
+ */
+function countIdentifiers(parsedSelector) {
+    switch (parsedSelector.type) {
+        case "child":
+        case "descendant":
+        case "sibling":
+        case "adjacent":
+            return countIdentifiers(parsedSelector.left) + countIdentifiers(parsedSelector.right);
+
+        case "compound":
+        case "not":
+        case "matches":
+            return parsedSelector.selectors.reduce((sum, childSelector) => sum + countIdentifiers(childSelector), 0);
+
+        case "identifier":
+            return 1;
+
+        default:
+            return 0;
+    }
+}
+
+/**
+ * Compares the specificity of two selector objects, with CSS-like rules.
+ * @param {ASTSelector} selectorA An AST selector descriptor
+ * @param {ASTSelector} selectorB Another AST selector descriptor
+ * @returns {number}
+ * a value less than 0 if selectorA is less specific than selectorB
+ * a value greater than 0 if selectorA is more specific than selectorB
+ * a value less than 0 if selectorA and selectorB have the same specificity, and selectorA <= selectorB alphabetically
+ * a value greater than 0 if selectorA and selectorB have the same specificity, and selectorA > selectorB alphabetically
+ */
+function compareSpecificity(selectorA, selectorB) {
+    return selectorA.attributeCount - selectorB.attributeCount ||
+        selectorA.identifierCount - selectorB.identifierCount ||
+        (selectorA.rawSelector <= selectorB.rawSelector ? -1 : 1);
+}
+
+/**
+ * Parses a raw selector string, and throws a useful error if parsing fails.
+ * @param {string} rawSelector A raw AST selector
+ * @returns {Object} An object (from esquery) describing the matching behavior of this selector
+ * @throws {Error} An error if the selector is invalid
+ */
+function tryParseSelector(rawSelector) {
+    try {
+        return esquery.parse(rawSelector.replace(/:exit$/u, ""));
+    } catch (err) {
+        if (err.location && err.location.start && typeof err.location.start.offset === "number") {
+            throw new SyntaxError(`Syntax error in selector "${rawSelector}" at position ${err.location.start.offset}: ${err.message}`);
+        }
+        throw err;
+    }
+}
+
+const selectorCache = new Map();
+
+/**
+ * Parses a raw selector string, and returns the parsed selector along with specificity and type information.
+ * @param {string} rawSelector A raw AST selector
+ * @returns {ASTSelector} A selector descriptor
+ */
+function parseSelector(rawSelector) {
+    if (selectorCache.has(rawSelector)) {
+        return selectorCache.get(rawSelector);
+    }
+
+    const parsedSelector = tryParseSelector(rawSelector);
+
+    const result = {
+        rawSelector,
+        isExit: rawSelector.endsWith(":exit"),
+        parsedSelector,
+        listenerTypes: getPossibleTypes(parsedSelector),
+        attributeCount: countClassAttributes(parsedSelector),
+        identifierCount: countIdentifiers(parsedSelector)
+    };
+
+    selectorCache.set(rawSelector, result);
+    return result;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * The event generator for AST nodes.
+ * This implements below interface.
+ *
+ * ```ts
+ * interface EventGenerator {
+ *     emitter: SafeEmitter;
+ *     enterNode(node: ASTNode): void;
+ *     leaveNode(node: ASTNode): void;
+ * }
+ * ```
+ */
+class NodeEventGenerator {
+
+    /**
+     * @param {SafeEmitter} emitter
+     * An SafeEmitter which is the destination of events. This emitter must already
+     * have registered listeners for all of the events that it needs to listen for.
+     * (See lib/linter/safe-emitter.js for more details on `SafeEmitter`.)
+     * @param {ESQueryOptions} esqueryOptions `esquery` options for traversing custom nodes.
+     * @returns {NodeEventGenerator} new instance
+     */
+    constructor(emitter, esqueryOptions) {
+        this.emitter = emitter;
+        this.esqueryOptions = esqueryOptions;
+        this.currentAncestry = [];
+        this.enterSelectorsByNodeType = new Map();
+        this.exitSelectorsByNodeType = new Map();
+        this.anyTypeEnterSelectors = [];
+        this.anyTypeExitSelectors = [];
+
+        emitter.eventNames().forEach(rawSelector => {
+            const selector = parseSelector(rawSelector);
+
+            if (selector.listenerTypes) {
+                const typeMap = selector.isExit ? this.exitSelectorsByNodeType : this.enterSelectorsByNodeType;
+
+                selector.listenerTypes.forEach(nodeType => {
+                    if (!typeMap.has(nodeType)) {
+                        typeMap.set(nodeType, []);
+                    }
+                    typeMap.get(nodeType).push(selector);
+                });
+                return;
+            }
+            const selectors = selector.isExit ? this.anyTypeExitSelectors : this.anyTypeEnterSelectors;
+
+            selectors.push(selector);
+        });
+
+        this.anyTypeEnterSelectors.sort(compareSpecificity);
+        this.anyTypeExitSelectors.sort(compareSpecificity);
+        this.enterSelectorsByNodeType.forEach(selectorList => selectorList.sort(compareSpecificity));
+        this.exitSelectorsByNodeType.forEach(selectorList => selectorList.sort(compareSpecificity));
+    }
+
+    /**
+     * Checks a selector against a node, and emits it if it matches
+     * @param {ASTNode} node The node to check
+     * @param {ASTSelector} selector An AST selector descriptor
+     * @returns {void}
+     */
+    applySelector(node, selector) {
+        if (esquery.matches(node, selector.parsedSelector, this.currentAncestry, this.esqueryOptions)) {
+            this.emitter.emit(selector.rawSelector, node);
+        }
+    }
+
+    /**
+     * Applies all appropriate selectors to a node, in specificity order
+     * @param {ASTNode} node The node to check
+     * @param {boolean} isExit `false` if the node is currently being entered, `true` if it's currently being exited
+     * @returns {void}
+     */
+    applySelectors(node, isExit) {
+        const selectorsByNodeType = (isExit ? this.exitSelectorsByNodeType : this.enterSelectorsByNodeType).get(node.type) || [];
+        const anyTypeSelectors = isExit ? this.anyTypeExitSelectors : this.anyTypeEnterSelectors;
+
+        /*
+         * selectorsByNodeType and anyTypeSelectors were already sorted by specificity in the constructor.
+         * Iterate through each of them, applying selectors in the right order.
+         */
+        let selectorsByTypeIndex = 0;
+        let anyTypeSelectorsIndex = 0;
+
+        while (selectorsByTypeIndex < selectorsByNodeType.length || anyTypeSelectorsIndex < anyTypeSelectors.length) {
+            if (
+                selectorsByTypeIndex >= selectorsByNodeType.length ||
+                anyTypeSelectorsIndex < anyTypeSelectors.length &&
+                compareSpecificity(anyTypeSelectors[anyTypeSelectorsIndex], selectorsByNodeType[selectorsByTypeIndex]) < 0
+            ) {
+                this.applySelector(node, anyTypeSelectors[anyTypeSelectorsIndex++]);
+            } else {
+                this.applySelector(node, selectorsByNodeType[selectorsByTypeIndex++]);
+            }
+        }
+    }
+
+    /**
+     * Emits an event of entering AST node.
+     * @param {ASTNode} node A node which was entered.
+     * @returns {void}
+     */
+    enterNode(node) {
+        if (node.parent) {
+            this.currentAncestry.unshift(node.parent);
+        }
+        this.applySelectors(node, false);
+    }
+
+    /**
+     * Emits an event of leaving AST node.
+     * @param {ASTNode} node A node which was left.
+     * @returns {void}
+     */
+    leaveNode(node) {
+        this.applySelectors(node, true);
+        this.currentAncestry.shift();
+    }
+}
+
+module.exports = NodeEventGenerator;

qwen/nodejs/node_modules/eslint/lib/linter/report-translator.js

@@ -0,0 +1,369 @@
+/**
+ * @fileoverview A helper that translates context.report() calls from the rule API into generic problem objects
+ * @author Teddy Katz
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const assert = require("assert");
+const ruleFixer = require("./rule-fixer");
+const interpolate = require("./interpolate");
+
+//------------------------------------------------------------------------------
+// Typedefs
+//------------------------------------------------------------------------------
+
+/** @typedef {import("../shared/types").LintMessage} LintMessage */
+
+/**
+ * An error message description
+ * @typedef {Object} MessageDescriptor
+ * @property {ASTNode} [node] The reported node
+ * @property {Location} loc The location of the problem.
+ * @property {string} message The problem message.
+ * @property {Object} [data] Optional data to use to fill in placeholders in the
+ *      message.
+ * @property {Function} [fix] The function to call that creates a fix command.
+ * @property {Array<{desc?: string, messageId?: string, fix: Function}>} suggest Suggestion descriptions and functions to create a the associated fixes.
+ */
+
+//------------------------------------------------------------------------------
+// Module Definition
+//------------------------------------------------------------------------------
+
+
+/**
+ * Translates a multi-argument context.report() call into a single object argument call
+ * @param {...*} args A list of arguments passed to `context.report`
+ * @returns {MessageDescriptor} A normalized object containing report information
+ */
+function normalizeMultiArgReportCall(...args) {
+
+    // If there is one argument, it is considered to be a new-style call already.
+    if (args.length === 1) {
+
+        // Shallow clone the object to avoid surprises if reusing the descriptor
+        return Object.assign({}, args[0]);
+    }
+
+    // If the second argument is a string, the arguments are interpreted as [node, message, data, fix].
+    if (typeof args[1] === "string") {
+        return {
+            node: args[0],
+            message: args[1],
+            data: args[2],
+            fix: args[3]
+        };
+    }
+
+    // Otherwise, the arguments are interpreted as [node, loc, message, data, fix].
+    return {
+        node: args[0],
+        loc: args[1],
+        message: args[2],
+        data: args[3],
+        fix: args[4]
+    };
+}
+
+/**
+ * Asserts that either a loc or a node was provided, and the node is valid if it was provided.
+ * @param {MessageDescriptor} descriptor A descriptor to validate
+ * @returns {void}
+ * @throws AssertionError if neither a node nor a loc was provided, or if the node is not an object
+ */
+function assertValidNodeInfo(descriptor) {
+    if (descriptor.node) {
+        assert(typeof descriptor.node === "object", "Node must be an object");
+    } else {
+        assert(descriptor.loc, "Node must be provided when reporting error if location is not provided");
+    }
+}
+
+/**
+ * Normalizes a MessageDescriptor to always have a `loc` with `start` and `end` properties
+ * @param {MessageDescriptor} descriptor A descriptor for the report from a rule.
+ * @returns {{start: Location, end: (Location|null)}} An updated location that infers the `start` and `end` properties
+ * from the `node` of the original descriptor, or infers the `start` from the `loc` of the original descriptor.
+ */
+function normalizeReportLoc(descriptor) {
+    if (descriptor.loc) {
+        if (descriptor.loc.start) {
+            return descriptor.loc;
+        }
+        return { start: descriptor.loc, end: null };
+    }
+    return descriptor.node.loc;
+}
+
+/**
+ * Clones the given fix object.
+ * @param {Fix|null} fix The fix to clone.
+ * @returns {Fix|null} Deep cloned fix object or `null` if `null` or `undefined` was passed in.
+ */
+function cloneFix(fix) {
+    if (!fix) {
+        return null;
+    }
+
+    return {
+        range: [fix.range[0], fix.range[1]],
+        text: fix.text
+    };
+}
+
+/**
+ * Check that a fix has a valid range.
+ * @param {Fix|null} fix The fix to validate.
+ * @returns {void}
+ */
+function assertValidFix(fix) {
+    if (fix) {
+        assert(fix.range && typeof fix.range[0] === "number" && typeof fix.range[1] === "number", `Fix has invalid range: ${JSON.stringify(fix, null, 2)}`);
+    }
+}
+
+/**
+ * Compares items in a fixes array by range.
+ * @param {Fix} a The first message.
+ * @param {Fix} b The second message.
+ * @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
+ * @private
+ */
+function compareFixesByRange(a, b) {
+    return a.range[0] - b.range[0] || a.range[1] - b.range[1];
+}
+
+/**
+ * Merges the given fixes array into one.
+ * @param {Fix[]} fixes The fixes to merge.
+ * @param {SourceCode} sourceCode The source code object to get the text between fixes.
+ * @returns {{text: string, range: number[]}} The merged fixes
+ */
+function mergeFixes(fixes, sourceCode) {
+    for (const fix of fixes) {
+        assertValidFix(fix);
+    }
+
+    if (fixes.length === 0) {
+        return null;
+    }
+    if (fixes.length === 1) {
+        return cloneFix(fixes[0]);
+    }
+
+    fixes.sort(compareFixesByRange);
+
+    const originalText = sourceCode.text;
+    const start = fixes[0].range[0];
+    const end = fixes[fixes.length - 1].range[1];
+    let text = "";
+    let lastPos = Number.MIN_SAFE_INTEGER;
+
+    for (const fix of fixes) {
+        assert(fix.range[0] >= lastPos, "Fix objects must not be overlapped in a report.");
+
+        if (fix.range[0] >= 0) {
+            text += originalText.slice(Math.max(0, start, lastPos), fix.range[0]);
+        }
+        text += fix.text;
+        lastPos = fix.range[1];
+    }
+    text += originalText.slice(Math.max(0, start, lastPos), end);
+
+    return { range: [start, end], text };
+}
+
+/**
+ * Gets one fix object from the given descriptor.
+ * If the descriptor retrieves multiple fixes, this merges those to one.
+ * @param {MessageDescriptor} descriptor The report descriptor.
+ * @param {SourceCode} sourceCode The source code object to get text between fixes.
+ * @returns {({text: string, range: number[]}|null)} The fix for the descriptor
+ */
+function normalizeFixes(descriptor, sourceCode) {
+    if (typeof descriptor.fix !== "function") {
+        return null;
+    }
+
+    // @type {null | Fix | Fix[] | IterableIterator<Fix>}
+    const fix = descriptor.fix(ruleFixer);
+
+    // Merge to one.
+    if (fix && Symbol.iterator in fix) {
+        return mergeFixes(Array.from(fix), sourceCode);
+    }
+
+    assertValidFix(fix);
+    return cloneFix(fix);
+}
+
+/**
+ * Gets an array of suggestion objects from the given descriptor.
+ * @param {MessageDescriptor} descriptor The report descriptor.
+ * @param {SourceCode} sourceCode The source code object to get text between fixes.
+ * @param {Object} messages Object of meta messages for the rule.
+ * @returns {Array<SuggestionResult>} The suggestions for the descriptor
+ */
+function mapSuggestions(descriptor, sourceCode, messages) {
+    if (!descriptor.suggest || !Array.isArray(descriptor.suggest)) {
+        return [];
+    }
+
+    return descriptor.suggest
+        .map(suggestInfo => {
+            const computedDesc = suggestInfo.desc || messages[suggestInfo.messageId];
+
+            return {
+                ...suggestInfo,
+                desc: interpolate(computedDesc, suggestInfo.data),
+                fix: normalizeFixes(suggestInfo, sourceCode)
+            };
+        })
+
+        // Remove suggestions that didn't provide a fix
+        .filter(({ fix }) => fix);
+}
+
+/**
+ * Creates information about the report from a descriptor
+ * @param {Object} options Information about the problem
+ * @param {string} options.ruleId Rule ID
+ * @param {(0|1|2)} options.severity Rule severity
+ * @param {(ASTNode|null)} options.node Node
+ * @param {string} options.message Error message
+ * @param {string} [options.messageId] The error message ID.
+ * @param {{start: SourceLocation, end: (SourceLocation|null)}} options.loc Start and end location
+ * @param {{text: string, range: (number[]|null)}} options.fix The fix object
+ * @param {Array<{text: string, range: (number[]|null)}>} options.suggestions The array of suggestions objects
+ * @returns {LintMessage} Information about the report
+ */
+function createProblem(options) {
+    const problem = {
+        ruleId: options.ruleId,
+        severity: options.severity,
+        message: options.message,
+        line: options.loc.start.line,
+        column: options.loc.start.column + 1,
+        nodeType: options.node && options.node.type || null
+    };
+
+    /*
+     * If this isn’t in the conditional, some of the tests fail
+     * because `messageId` is present in the problem object
+     */
+    if (options.messageId) {
+        problem.messageId = options.messageId;
+    }
+
+    if (options.loc.end) {
+        problem.endLine = options.loc.end.line;
+        problem.endColumn = options.loc.end.column + 1;
+    }
+
+    if (options.fix) {
+        problem.fix = options.fix;
+    }
+
+    if (options.suggestions && options.suggestions.length > 0) {
+        problem.suggestions = options.suggestions;
+    }
+
+    return problem;
+}
+
+/**
+ * Validates that suggestions are properly defined. Throws if an error is detected.
+ * @param {Array<{ desc?: string, messageId?: string }>} suggest The incoming suggest data.
+ * @param {Object} messages Object of meta messages for the rule.
+ * @returns {void}
+ */
+function validateSuggestions(suggest, messages) {
+    if (suggest && Array.isArray(suggest)) {
+        suggest.forEach(suggestion => {
+            if (suggestion.messageId) {
+                const { messageId } = suggestion;
+
+                if (!messages) {
+                    throw new TypeError(`context.report() called with a suggest option with a messageId '${messageId}', but no messages were present in the rule metadata.`);
+                }
+
+                if (!messages[messageId]) {
+                    throw new TypeError(`context.report() called with a suggest option with a messageId '${messageId}' which is not present in the 'messages' config: ${JSON.stringify(messages, null, 2)}`);
+                }
+
+                if (suggestion.desc) {
+                    throw new TypeError("context.report() called with a suggest option that defines both a 'messageId' and an 'desc'. Please only pass one.");
+                }
+            } else if (!suggestion.desc) {
+                throw new TypeError("context.report() called with a suggest option that doesn't have either a `desc` or `messageId`");
+            }
+
+            if (typeof suggestion.fix !== "function") {
+                throw new TypeError(`context.report() called with a suggest option without a fix function. See: ${suggestion}`);
+            }
+        });
+    }
+}
+
+/**
+ * Returns a function that converts the arguments of a `context.report` call from a rule into a reported
+ * problem for the Node.js API.
+ * @param {{ruleId: string, severity: number, sourceCode: SourceCode, messageIds: Object, disableFixes: boolean}} metadata Metadata for the reported problem
+ * @param {SourceCode} sourceCode The `SourceCode` instance for the text being linted
+ * @returns {function(...args): LintMessage} Function that returns information about the report
+ */
+
+module.exports = function createReportTranslator(metadata) {
+
+    /*
+     * `createReportTranslator` gets called once per enabled rule per file. It needs to be very performant.
+     * The report translator itself (i.e. the function that `createReportTranslator` returns) gets
+     * called every time a rule reports a problem, which happens much less frequently (usually, the vast
+     * majority of rules don't report any problems for a given file).
+     */
+    return (...args) => {
+        const descriptor = normalizeMultiArgReportCall(...args);
+        const messages = metadata.messageIds;
+
+        assertValidNodeInfo(descriptor);
+
+        let computedMessage;
+
+        if (descriptor.messageId) {
+            if (!messages) {
+                throw new TypeError("context.report() called with a messageId, but no messages were present in the rule metadata.");
+            }
+            const id = descriptor.messageId;
+
+            if (descriptor.message) {
+                throw new TypeError("context.report() called with a message and a messageId. Please only pass one.");
+            }
+            if (!messages || !Object.prototype.hasOwnProperty.call(messages, id)) {
+                throw new TypeError(`context.report() called with a messageId of '${id}' which is not present in the 'messages' config: ${JSON.stringify(messages, null, 2)}`);
+            }
+            computedMessage = messages[id];
+        } else if (descriptor.message) {
+            computedMessage = descriptor.message;
+        } else {
+            throw new TypeError("Missing `message` property in report() call; add a message that describes the linting problem.");
+        }
+
+        validateSuggestions(descriptor.suggest, messages);
+
+        return createProblem({
+            ruleId: metadata.ruleId,
+            severity: metadata.severity,
+            node: descriptor.node,
+            message: interpolate(computedMessage, descriptor.data),
+            messageId: descriptor.messageId,
+            loc: normalizeReportLoc(descriptor),
+            fix: metadata.disableFixes ? null : normalizeFixes(descriptor, metadata.sourceCode),
+            suggestions: metadata.disableFixes ? [] : mapSuggestions(descriptor, metadata.sourceCode, messages)
+        });
+    };
+};

qwen/nodejs/node_modules/eslint/lib/linter/rule-fixer.js

@@ -0,0 +1,140 @@
+/**
+ * @fileoverview An object that creates fix commands for rules.
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+// none!
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Creates a fix command that inserts text at the specified index in the source text.
+ * @param {int} index The 0-based index at which to insert the new text.
+ * @param {string} text The text to insert.
+ * @returns {Object} The fix command.
+ * @private
+ */
+function insertTextAt(index, text) {
+    return {
+        range: [index, index],
+        text
+    };
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Creates code fixing commands for rules.
+ */
+
+const ruleFixer = Object.freeze({
+
+    /**
+     * Creates a fix command that inserts text after the given node or token.
+     * The fix is not applied until applyFixes() is called.
+     * @param {ASTNode|Token} nodeOrToken The node or token to insert after.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    insertTextAfter(nodeOrToken, text) {
+        return this.insertTextAfterRange(nodeOrToken.range, text);
+    },
+
+    /**
+     * Creates a fix command that inserts text after the specified range in the source text.
+     * The fix is not applied until applyFixes() is called.
+     * @param {int[]} range The range to replace, first item is start of range, second
+     *      is end of range.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    insertTextAfterRange(range, text) {
+        return insertTextAt(range[1], text);
+    },
+
+    /**
+     * Creates a fix command that inserts text before the given node or token.
+     * The fix is not applied until applyFixes() is called.
+     * @param {ASTNode|Token} nodeOrToken The node or token to insert before.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    insertTextBefore(nodeOrToken, text) {
+        return this.insertTextBeforeRange(nodeOrToken.range, text);
+    },
+
+    /**
+     * Creates a fix command that inserts text before the specified range in the source text.
+     * The fix is not applied until applyFixes() is called.
+     * @param {int[]} range The range to replace, first item is start of range, second
+     *      is end of range.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    insertTextBeforeRange(range, text) {
+        return insertTextAt(range[0], text);
+    },
+
+    /**
+     * Creates a fix command that replaces text at the node or token.
+     * The fix is not applied until applyFixes() is called.
+     * @param {ASTNode|Token} nodeOrToken The node or token to remove.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    replaceText(nodeOrToken, text) {
+        return this.replaceTextRange(nodeOrToken.range, text);
+    },
+
+    /**
+     * Creates a fix command that replaces text at the specified range in the source text.
+     * The fix is not applied until applyFixes() is called.
+     * @param {int[]} range The range to replace, first item is start of range, second
+     *      is end of range.
+     * @param {string} text The text to insert.
+     * @returns {Object} The fix command.
+     */
+    replaceTextRange(range, text) {
+        return {
+            range,
+            text
+        };
+    },
+
+    /**
+     * Creates a fix command that removes the node or token from the source.
+     * The fix is not applied until applyFixes() is called.
+     * @param {ASTNode|Token} nodeOrToken The node or token to remove.
+     * @returns {Object} The fix command.
+     */
+    remove(nodeOrToken) {
+        return this.removeRange(nodeOrToken.range);
+    },
+
+    /**
+     * Creates a fix command that removes the specified range of text from the source.
+     * The fix is not applied until applyFixes() is called.
+     * @param {int[]} range The range to remove, first item is start of range, second
+     *      is end of range.
+     * @returns {Object} The fix command.
+     */
+    removeRange(range) {
+        return {
+            range,
+            text: ""
+        };
+    }
+
+});
+
+
+module.exports = ruleFixer;

qwen/nodejs/node_modules/eslint/lib/linter/rules.js

@@ -0,0 +1,80 @@
+/**
+ * @fileoverview Defines a storage for rules.
+ * @author Nicholas C. Zakas
+ * @author aladdin-add
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const builtInRules = require("../rules");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Normalizes a rule module to the new-style API
+ * @param {(Function|{create: Function})} rule A rule object, which can either be a function
+ * ("old-style") or an object with a `create` method ("new-style")
+ * @returns {{create: Function}} A new-style rule.
+ */
+function normalizeRule(rule) {
+    return typeof rule === "function" ? Object.assign({ create: rule }, rule) : rule;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * A storage for rules.
+ */
+class Rules {
+    constructor() {
+        this._rules = Object.create(null);
+    }
+
+    /**
+     * Registers a rule module for rule id in storage.
+     * @param {string} ruleId Rule id (file name).
+     * @param {Function} ruleModule Rule handler.
+     * @returns {void}
+     */
+    define(ruleId, ruleModule) {
+        this._rules[ruleId] = normalizeRule(ruleModule);
+    }
+
+    /**
+     * Access rule handler by id (file name).
+     * @param {string} ruleId Rule id (file name).
+     * @returns {{create: Function, schema: JsonSchema[]}}
+     * A rule. This is normalized to always have the new-style shape with a `create` method.
+     */
+    get(ruleId) {
+        if (typeof this._rules[ruleId] === "string") {
+            this.define(ruleId, require(this._rules[ruleId]));
+        }
+        if (this._rules[ruleId]) {
+            return this._rules[ruleId];
+        }
+        if (builtInRules.has(ruleId)) {
+            return builtInRules.get(ruleId);
+        }
+
+        return null;
+    }
+
+    *[Symbol.iterator]() {
+        yield* builtInRules;
+
+        for (const ruleId of Object.keys(this._rules)) {
+            yield [ruleId, this.get(ruleId)];
+        }
+    }
+}
+
+module.exports = Rules;

qwen/nodejs/node_modules/eslint/lib/linter/safe-emitter.js

@@ -0,0 +1,52 @@
+/**
+ * @fileoverview A variant of EventEmitter which does not give listeners information about each other
+ * @author Teddy Katz
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Typedefs
+//------------------------------------------------------------------------------
+
+/**
+ * An event emitter
+ * @typedef {Object} SafeEmitter
+ * @property {(eventName: string, listenerFunc: Function) => void} on Adds a listener for a given event name
+ * @property {(eventName: string, arg1?: any, arg2?: any, arg3?: any) => void} emit Emits an event with a given name.
+ * This calls all the listeners that were listening for that name, with `arg1`, `arg2`, and `arg3` as arguments.
+ * @property {function(): string[]} eventNames Gets the list of event names that have registered listeners.
+ */
+
+/**
+ * Creates an object which can listen for and emit events.
+ * This is similar to the EventEmitter API in Node's standard library, but it has a few differences.
+ * The goal is to allow multiple modules to attach arbitrary listeners to the same emitter, without
+ * letting the modules know about each other at all.
+ * 1. It has no special keys like `error` and `newListener`, which would allow modules to detect when
+ * another module throws an error or registers a listener.
+ * 2. It calls listener functions without any `this` value. (`EventEmitter` calls listeners with a
+ * `this` value of the emitter instance, which would give listeners access to other listeners.)
+ * @returns {SafeEmitter} An emitter
+ */
+module.exports = () => {
+    const listeners = Object.create(null);
+
+    return Object.freeze({
+        on(eventName, listener) {
+            if (eventName in listeners) {
+                listeners[eventName].push(listener);
+            } else {
+                listeners[eventName] = [listener];
+            }
+        },
+        emit(eventName, ...args) {
+            if (eventName in listeners) {
+                listeners[eventName].forEach(listener => listener(...args));
+            }
+        },
+        eventNames() {
+            return Object.keys(listeners);
+        }
+    });
+};

qwen/nodejs/node_modules/eslint/lib/linter/source-code-fixer.js

@@ -0,0 +1,152 @@
+/**
+ * @fileoverview An object that caches and applies source code fixes.
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const debug = require("debug")("eslint:source-code-fixer");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+const BOM = "\uFEFF";
+
+/**
+ * Compares items in a messages array by range.
+ * @param {Message} a The first message.
+ * @param {Message} b The second message.
+ * @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
+ * @private
+ */
+function compareMessagesByFixRange(a, b) {
+    return a.fix.range[0] - b.fix.range[0] || a.fix.range[1] - b.fix.range[1];
+}
+
+/**
+ * Compares items in a messages array by line and column.
+ * @param {Message} a The first message.
+ * @param {Message} b The second message.
+ * @returns {int} -1 if a comes before b, 1 if a comes after b, 0 if equal.
+ * @private
+ */
+function compareMessagesByLocation(a, b) {
+    return a.line - b.line || a.column - b.column;
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Utility for apply fixes to source code.
+ * @constructor
+ */
+function SourceCodeFixer() {
+    Object.freeze(this);
+}
+
+/**
+ * Applies the fixes specified by the messages to the given text. Tries to be
+ * smart about the fixes and won't apply fixes over the same area in the text.
+ * @param {string} sourceText The text to apply the changes to.
+ * @param {Message[]} messages The array of messages reported by ESLint.
+ * @param {boolean|Function} [shouldFix=true] Determines whether each message should be fixed
+ * @returns {Object} An object containing the fixed text and any unfixed messages.
+ */
+SourceCodeFixer.applyFixes = function(sourceText, messages, shouldFix) {
+    debug("Applying fixes");
+
+    if (shouldFix === false) {
+        debug("shouldFix parameter was false, not attempting fixes");
+        return {
+            fixed: false,
+            messages,
+            output: sourceText
+        };
+    }
+
+    // clone the array
+    const remainingMessages = [],
+        fixes = [],
+        bom = sourceText.startsWith(BOM) ? BOM : "",
+        text = bom ? sourceText.slice(1) : sourceText;
+    let lastPos = Number.NEGATIVE_INFINITY,
+        output = bom;
+
+    /**
+     * Try to use the 'fix' from a problem.
+     * @param {Message} problem The message object to apply fixes from
+     * @returns {boolean} Whether fix was successfully applied
+     */
+    function attemptFix(problem) {
+        const fix = problem.fix;
+        const start = fix.range[0];
+        const end = fix.range[1];
+
+        // Remain it as a problem if it's overlapped or it's a negative range
+        if (lastPos >= start || start > end) {
+            remainingMessages.push(problem);
+            return false;
+        }
+
+        // Remove BOM.
+        if ((start < 0 && end >= 0) || (start === 0 && fix.text.startsWith(BOM))) {
+            output = "";
+        }
+
+        // Make output to this fix.
+        output += text.slice(Math.max(0, lastPos), Math.max(0, start));
+        output += fix.text;
+        lastPos = end;
+        return true;
+    }
+
+    messages.forEach(problem => {
+        if (Object.prototype.hasOwnProperty.call(problem, "fix")) {
+            fixes.push(problem);
+        } else {
+            remainingMessages.push(problem);
+        }
+    });
+
+    if (fixes.length) {
+        debug("Found fixes to apply");
+        let fixesWereApplied = false;
+
+        for (const problem of fixes.sort(compareMessagesByFixRange)) {
+            if (typeof shouldFix !== "function" || shouldFix(problem)) {
+                attemptFix(problem);
+
+                /*
+                 * The only time attemptFix will fail is if a previous fix was
+                 * applied which conflicts with it.  So we can mark this as true.
+                 */
+                fixesWereApplied = true;
+            } else {
+                remainingMessages.push(problem);
+            }
+        }
+        output += text.slice(Math.max(0, lastPos));
+
+        return {
+            fixed: fixesWereApplied,
+            messages: remainingMessages.sort(compareMessagesByLocation),
+            output
+        };
+    }
+
+    debug("No fixes to apply");
+    return {
+        fixed: false,
+        messages,
+        output: bom + text
+    };
+
+};
+
+module.exports = SourceCodeFixer;

qwen/nodejs/node_modules/eslint/lib/linter/timing.js

@@ -0,0 +1,161 @@
+/**
+ * @fileoverview Tracks performance of individual rules.
+ * @author Brandon Mills
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/* c8 ignore next */
+/**
+ * Align the string to left
+ * @param {string} str string to evaluate
+ * @param {int} len length of the string
+ * @param {string} ch delimiter character
+ * @returns {string} modified string
+ * @private
+ */
+function alignLeft(str, len, ch) {
+    return str + new Array(len - str.length + 1).join(ch || " ");
+}
+
+/* c8 ignore next */
+/**
+ * Align the string to right
+ * @param {string} str string to evaluate
+ * @param {int} len length of the string
+ * @param {string} ch delimiter character
+ * @returns {string} modified string
+ * @private
+ */
+function alignRight(str, len, ch) {
+    return new Array(len - str.length + 1).join(ch || " ") + str;
+}
+
+//------------------------------------------------------------------------------
+// Module definition
+//------------------------------------------------------------------------------
+
+const enabled = !!process.env.TIMING;
+
+const HEADERS = ["Rule", "Time (ms)", "Relative"];
+const ALIGN = [alignLeft, alignRight, alignRight];
+
+/**
+ * Decide how many rules to show in the output list.
+ * @returns {number} the number of rules to show
+ */
+function getListSize() {
+    const MINIMUM_SIZE = 10;
+
+    if (typeof process.env.TIMING !== "string") {
+        return MINIMUM_SIZE;
+    }
+
+    if (process.env.TIMING.toLowerCase() === "all") {
+        return Number.POSITIVE_INFINITY;
+    }
+
+    const TIMING_ENV_VAR_AS_INTEGER = Number.parseInt(process.env.TIMING, 10);
+
+    return TIMING_ENV_VAR_AS_INTEGER > 10 ? TIMING_ENV_VAR_AS_INTEGER : MINIMUM_SIZE;
+}
+
+/* c8 ignore next */
+/**
+ * display the data
+ * @param {Object} data Data object to be displayed
+ * @returns {void} prints modified string with console.log
+ * @private
+ */
+function display(data) {
+    let total = 0;
+    const rows = Object.keys(data)
+        .map(key => {
+            const time = data[key];
+
+            total += time;
+            return [key, time];
+        })
+        .sort((a, b) => b[1] - a[1])
+        .slice(0, getListSize());
+
+    rows.forEach(row => {
+        row.push(`${(row[1] * 100 / total).toFixed(1)}%`);
+        row[1] = row[1].toFixed(3);
+    });
+
+    rows.unshift(HEADERS);
+
+    const widths = [];
+
+    rows.forEach(row => {
+        const len = row.length;
+
+        for (let i = 0; i < len; i++) {
+            const n = row[i].length;
+
+            if (!widths[i] || n > widths[i]) {
+                widths[i] = n;
+            }
+        }
+    });
+
+    const table = rows.map(row => (
+        row
+            .map((cell, index) => ALIGN[index](cell, widths[index]))
+            .join(" | ")
+    ));
+
+    table.splice(1, 0, widths.map((width, index) => {
+        const extraAlignment = index !== 0 && index !== widths.length - 1 ? 2 : 1;
+
+        return ALIGN[index](":", width + extraAlignment, "-");
+    }).join("|"));
+
+    console.log(table.join("\n")); // eslint-disable-line no-console -- Debugging function
+}
+
+/* c8 ignore next */
+module.exports = (function() {
+
+    const data = Object.create(null);
+
+    /**
+     * Time the run
+     * @param {any} key key from the data object
+     * @param {Function} fn function to be called
+     * @returns {Function} function to be executed
+     * @private
+     */
+    function time(key, fn) {
+        if (typeof data[key] === "undefined") {
+            data[key] = 0;
+        }
+
+        return function(...args) {
+            let t = process.hrtime();
+            const result = fn(...args);
+
+            t = process.hrtime(t);
+            data[key] += t[0] * 1e3 + t[1] / 1e6;
+            return result;
+        };
+    }
+
+    if (enabled) {
+        process.on("exit", () => {
+            display(data);
+        });
+    }
+
+    return {
+        time,
+        enabled,
+        getListSize
+    };
+
+}());