.
This commit is contained in:
		
							
								
								
									
										718
									
								
								qwen/nodejs/node_modules/eslint/lib/rules/no-unused-vars.js
									
									
									
										generated
									
									
										vendored
									
									
										Normal file
									
								
							
							
						
						
									
										718
									
								
								qwen/nodejs/node_modules/eslint/lib/rules/no-unused-vars.js
									
									
									
										generated
									
									
										vendored
									
									
										Normal file
									
								
							@@ -0,0 +1,718 @@
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		||||
/**
 | 
			
		||||
 * @fileoverview Rule to flag declared but unused variables
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		||||
 * @author Ilya Volodin
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		||||
 */
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		||||
 | 
			
		||||
"use strict";
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		||||
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		||||
//------------------------------------------------------------------------------
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		||||
// Requirements
 | 
			
		||||
//------------------------------------------------------------------------------
 | 
			
		||||
 | 
			
		||||
const astUtils = require("./utils/ast-utils");
 | 
			
		||||
 | 
			
		||||
//------------------------------------------------------------------------------
 | 
			
		||||
// Typedefs
 | 
			
		||||
//------------------------------------------------------------------------------
 | 
			
		||||
 | 
			
		||||
/**
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		||||
 * Bag of data used for formatting the `unusedVar` lint message.
 | 
			
		||||
 * @typedef {Object} UnusedVarMessageData
 | 
			
		||||
 * @property {string} varName The name of the unused var.
 | 
			
		||||
 * @property {'defined'|'assigned a value'} action Description of the vars state.
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		||||
 * @property {string} additional Any additional info to be appended at the end.
 | 
			
		||||
 */
 | 
			
		||||
 | 
			
		||||
//------------------------------------------------------------------------------
 | 
			
		||||
// Rule Definition
 | 
			
		||||
//------------------------------------------------------------------------------
 | 
			
		||||
 | 
			
		||||
/** @type {import('../shared/types').Rule} */
 | 
			
		||||
module.exports = {
 | 
			
		||||
    meta: {
 | 
			
		||||
        type: "problem",
 | 
			
		||||
 | 
			
		||||
        docs: {
 | 
			
		||||
            description: "Disallow unused variables",
 | 
			
		||||
            recommended: true,
 | 
			
		||||
            url: "https://eslint.org/docs/latest/rules/no-unused-vars"
 | 
			
		||||
        },
 | 
			
		||||
 | 
			
		||||
        schema: [
 | 
			
		||||
            {
 | 
			
		||||
                oneOf: [
 | 
			
		||||
                    {
 | 
			
		||||
                        enum: ["all", "local"]
 | 
			
		||||
                    },
 | 
			
		||||
                    {
 | 
			
		||||
                        type: "object",
 | 
			
		||||
                        properties: {
 | 
			
		||||
                            vars: {
 | 
			
		||||
                                enum: ["all", "local"]
 | 
			
		||||
                            },
 | 
			
		||||
                            varsIgnorePattern: {
 | 
			
		||||
                                type: "string"
 | 
			
		||||
                            },
 | 
			
		||||
                            args: {
 | 
			
		||||
                                enum: ["all", "after-used", "none"]
 | 
			
		||||
                            },
 | 
			
		||||
                            ignoreRestSiblings: {
 | 
			
		||||
                                type: "boolean"
 | 
			
		||||
                            },
 | 
			
		||||
                            argsIgnorePattern: {
 | 
			
		||||
                                type: "string"
 | 
			
		||||
                            },
 | 
			
		||||
                            caughtErrors: {
 | 
			
		||||
                                enum: ["all", "none"]
 | 
			
		||||
                            },
 | 
			
		||||
                            caughtErrorsIgnorePattern: {
 | 
			
		||||
                                type: "string"
 | 
			
		||||
                            },
 | 
			
		||||
                            destructuredArrayIgnorePattern: {
 | 
			
		||||
                                type: "string"
 | 
			
		||||
                            }
 | 
			
		||||
                        },
 | 
			
		||||
                        additionalProperties: false
 | 
			
		||||
                    }
 | 
			
		||||
                ]
 | 
			
		||||
            }
 | 
			
		||||
        ],
 | 
			
		||||
 | 
			
		||||
        messages: {
 | 
			
		||||
            unusedVar: "'{{varName}}' is {{action}} but never used{{additional}}."
 | 
			
		||||
        }
 | 
			
		||||
    },
 | 
			
		||||
 | 
			
		||||
    create(context) {
 | 
			
		||||
        const sourceCode = context.sourceCode;
 | 
			
		||||
 | 
			
		||||
        const REST_PROPERTY_TYPE = /^(?:RestElement|(?:Experimental)?RestProperty)$/u;
 | 
			
		||||
 | 
			
		||||
        const config = {
 | 
			
		||||
            vars: "all",
 | 
			
		||||
            args: "after-used",
 | 
			
		||||
            ignoreRestSiblings: false,
 | 
			
		||||
            caughtErrors: "none"
 | 
			
		||||
        };
 | 
			
		||||
 | 
			
		||||
        const firstOption = context.options[0];
 | 
			
		||||
 | 
			
		||||
        if (firstOption) {
 | 
			
		||||
            if (typeof firstOption === "string") {
 | 
			
		||||
                config.vars = firstOption;
 | 
			
		||||
            } else {
 | 
			
		||||
                config.vars = firstOption.vars || config.vars;
 | 
			
		||||
                config.args = firstOption.args || config.args;
 | 
			
		||||
                config.ignoreRestSiblings = firstOption.ignoreRestSiblings || config.ignoreRestSiblings;
 | 
			
		||||
                config.caughtErrors = firstOption.caughtErrors || config.caughtErrors;
 | 
			
		||||
 | 
			
		||||
                if (firstOption.varsIgnorePattern) {
 | 
			
		||||
                    config.varsIgnorePattern = new RegExp(firstOption.varsIgnorePattern, "u");
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                if (firstOption.argsIgnorePattern) {
 | 
			
		||||
                    config.argsIgnorePattern = new RegExp(firstOption.argsIgnorePattern, "u");
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                if (firstOption.caughtErrorsIgnorePattern) {
 | 
			
		||||
                    config.caughtErrorsIgnorePattern = new RegExp(firstOption.caughtErrorsIgnorePattern, "u");
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                if (firstOption.destructuredArrayIgnorePattern) {
 | 
			
		||||
                    config.destructuredArrayIgnorePattern = new RegExp(firstOption.destructuredArrayIgnorePattern, "u");
 | 
			
		||||
                }
 | 
			
		||||
            }
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Generates the message data about the variable being defined and unused,
 | 
			
		||||
         * including the ignore pattern if configured.
 | 
			
		||||
         * @param {Variable} unusedVar eslint-scope variable object.
 | 
			
		||||
         * @returns {UnusedVarMessageData} The message data to be used with this unused variable.
 | 
			
		||||
         */
 | 
			
		||||
        function getDefinedMessageData(unusedVar) {
 | 
			
		||||
            const defType = unusedVar.defs && unusedVar.defs[0] && unusedVar.defs[0].type;
 | 
			
		||||
            let type;
 | 
			
		||||
            let pattern;
 | 
			
		||||
 | 
			
		||||
            if (defType === "CatchClause" && config.caughtErrorsIgnorePattern) {
 | 
			
		||||
                type = "args";
 | 
			
		||||
                pattern = config.caughtErrorsIgnorePattern.toString();
 | 
			
		||||
            } else if (defType === "Parameter" && config.argsIgnorePattern) {
 | 
			
		||||
                type = "args";
 | 
			
		||||
                pattern = config.argsIgnorePattern.toString();
 | 
			
		||||
            } else if (defType !== "Parameter" && config.varsIgnorePattern) {
 | 
			
		||||
                type = "vars";
 | 
			
		||||
                pattern = config.varsIgnorePattern.toString();
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            const additional = type ? `. Allowed unused ${type} must match ${pattern}` : "";
 | 
			
		||||
 | 
			
		||||
            return {
 | 
			
		||||
                varName: unusedVar.name,
 | 
			
		||||
                action: "defined",
 | 
			
		||||
                additional
 | 
			
		||||
            };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Generate the warning message about the variable being
 | 
			
		||||
         * assigned and unused, including the ignore pattern if configured.
 | 
			
		||||
         * @param {Variable} unusedVar eslint-scope variable object.
 | 
			
		||||
         * @returns {UnusedVarMessageData} The message data to be used with this unused variable.
 | 
			
		||||
         */
 | 
			
		||||
        function getAssignedMessageData(unusedVar) {
 | 
			
		||||
            const def = unusedVar.defs[0];
 | 
			
		||||
            let additional = "";
 | 
			
		||||
 | 
			
		||||
            if (config.destructuredArrayIgnorePattern && def && def.name.parent.type === "ArrayPattern") {
 | 
			
		||||
                additional = `. Allowed unused elements of array destructuring patterns must match ${config.destructuredArrayIgnorePattern.toString()}`;
 | 
			
		||||
            } else if (config.varsIgnorePattern) {
 | 
			
		||||
                additional = `. Allowed unused vars must match ${config.varsIgnorePattern.toString()}`;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return {
 | 
			
		||||
                varName: unusedVar.name,
 | 
			
		||||
                action: "assigned a value",
 | 
			
		||||
                additional
 | 
			
		||||
            };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        //--------------------------------------------------------------------------
 | 
			
		||||
        // Helpers
 | 
			
		||||
        //--------------------------------------------------------------------------
 | 
			
		||||
 | 
			
		||||
        const STATEMENT_TYPE = /(?:Statement|Declaration)$/u;
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determines if a given variable is being exported from a module.
 | 
			
		||||
         * @param {Variable} variable eslint-scope variable object.
 | 
			
		||||
         * @returns {boolean} True if the variable is exported, false if not.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isExported(variable) {
 | 
			
		||||
 | 
			
		||||
            const definition = variable.defs[0];
 | 
			
		||||
 | 
			
		||||
            if (definition) {
 | 
			
		||||
 | 
			
		||||
                let node = definition.node;
 | 
			
		||||
 | 
			
		||||
                if (node.type === "VariableDeclarator") {
 | 
			
		||||
                    node = node.parent;
 | 
			
		||||
                } else if (definition.type === "Parameter") {
 | 
			
		||||
                    return false;
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                return node.parent.type.indexOf("Export") === 0;
 | 
			
		||||
            }
 | 
			
		||||
            return false;
 | 
			
		||||
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether a node is a sibling of the rest property or not.
 | 
			
		||||
         * @param {ASTNode} node a node to check
 | 
			
		||||
         * @returns {boolean} True if the node is a sibling of the rest property, otherwise false.
 | 
			
		||||
         */
 | 
			
		||||
        function hasRestSibling(node) {
 | 
			
		||||
            return node.type === "Property" &&
 | 
			
		||||
                node.parent.type === "ObjectPattern" &&
 | 
			
		||||
                REST_PROPERTY_TYPE.test(node.parent.properties[node.parent.properties.length - 1].type);
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determines if a variable has a sibling rest property
 | 
			
		||||
         * @param {Variable} variable eslint-scope variable object.
 | 
			
		||||
         * @returns {boolean} True if the variable is exported, false if not.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function hasRestSpreadSibling(variable) {
 | 
			
		||||
            if (config.ignoreRestSiblings) {
 | 
			
		||||
                const hasRestSiblingDefinition = variable.defs.some(def => hasRestSibling(def.name.parent));
 | 
			
		||||
                const hasRestSiblingReference = variable.references.some(ref => hasRestSibling(ref.identifier.parent));
 | 
			
		||||
 | 
			
		||||
                return hasRestSiblingDefinition || hasRestSiblingReference;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return false;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determines if a reference is a read operation.
 | 
			
		||||
         * @param {Reference} ref An eslint-scope Reference
 | 
			
		||||
         * @returns {boolean} whether the given reference represents a read operation
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isReadRef(ref) {
 | 
			
		||||
            return ref.isRead();
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determine if an identifier is referencing an enclosing function name.
 | 
			
		||||
         * @param {Reference} ref The reference to check.
 | 
			
		||||
         * @param {ASTNode[]} nodes The candidate function nodes.
 | 
			
		||||
         * @returns {boolean} True if it's a self-reference, false if not.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isSelfReference(ref, nodes) {
 | 
			
		||||
            let scope = ref.from;
 | 
			
		||||
 | 
			
		||||
            while (scope) {
 | 
			
		||||
                if (nodes.includes(scope.block)) {
 | 
			
		||||
                    return true;
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                scope = scope.upper;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return false;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Gets a list of function definitions for a specified variable.
 | 
			
		||||
         * @param {Variable} variable eslint-scope variable object.
 | 
			
		||||
         * @returns {ASTNode[]} Function nodes.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function getFunctionDefinitions(variable) {
 | 
			
		||||
            const functionDefinitions = [];
 | 
			
		||||
 | 
			
		||||
            variable.defs.forEach(def => {
 | 
			
		||||
                const { type, node } = def;
 | 
			
		||||
 | 
			
		||||
                // FunctionDeclarations
 | 
			
		||||
                if (type === "FunctionName") {
 | 
			
		||||
                    functionDefinitions.push(node);
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                // FunctionExpressions
 | 
			
		||||
                if (type === "Variable" && node.init &&
 | 
			
		||||
                    (node.init.type === "FunctionExpression" || node.init.type === "ArrowFunctionExpression")) {
 | 
			
		||||
                    functionDefinitions.push(node.init);
 | 
			
		||||
                }
 | 
			
		||||
            });
 | 
			
		||||
            return functionDefinitions;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks the position of given nodes.
 | 
			
		||||
         * @param {ASTNode} inner A node which is expected as inside.
 | 
			
		||||
         * @param {ASTNode} outer A node which is expected as outside.
 | 
			
		||||
         * @returns {boolean} `true` if the `inner` node exists in the `outer` node.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isInside(inner, outer) {
 | 
			
		||||
            return (
 | 
			
		||||
                inner.range[0] >= outer.range[0] &&
 | 
			
		||||
                inner.range[1] <= outer.range[1]
 | 
			
		||||
            );
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether a given node is unused expression or not.
 | 
			
		||||
         * @param {ASTNode} node The node itself
 | 
			
		||||
         * @returns {boolean} The node is an unused expression.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isUnusedExpression(node) {
 | 
			
		||||
            const parent = node.parent;
 | 
			
		||||
 | 
			
		||||
            if (parent.type === "ExpressionStatement") {
 | 
			
		||||
                return true;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            if (parent.type === "SequenceExpression") {
 | 
			
		||||
                const isLastExpression = parent.expressions[parent.expressions.length - 1] === node;
 | 
			
		||||
 | 
			
		||||
                if (!isLastExpression) {
 | 
			
		||||
                    return true;
 | 
			
		||||
                }
 | 
			
		||||
                return isUnusedExpression(parent);
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return false;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * If a given reference is left-hand side of an assignment, this gets
 | 
			
		||||
         * the right-hand side node of the assignment.
 | 
			
		||||
         *
 | 
			
		||||
         * In the following cases, this returns null.
 | 
			
		||||
         *
 | 
			
		||||
         * - The reference is not the LHS of an assignment expression.
 | 
			
		||||
         * - The reference is inside of a loop.
 | 
			
		||||
         * - The reference is inside of a function scope which is different from
 | 
			
		||||
         *   the declaration.
 | 
			
		||||
         * @param {eslint-scope.Reference} ref A reference to check.
 | 
			
		||||
         * @param {ASTNode} prevRhsNode The previous RHS node.
 | 
			
		||||
         * @returns {ASTNode|null} The RHS node or null.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function getRhsNode(ref, prevRhsNode) {
 | 
			
		||||
            const id = ref.identifier;
 | 
			
		||||
            const parent = id.parent;
 | 
			
		||||
            const refScope = ref.from.variableScope;
 | 
			
		||||
            const varScope = ref.resolved.scope.variableScope;
 | 
			
		||||
            const canBeUsedLater = refScope !== varScope || astUtils.isInLoop(id);
 | 
			
		||||
 | 
			
		||||
            /*
 | 
			
		||||
             * Inherits the previous node if this reference is in the node.
 | 
			
		||||
             * This is for `a = a + a`-like code.
 | 
			
		||||
             */
 | 
			
		||||
            if (prevRhsNode && isInside(id, prevRhsNode)) {
 | 
			
		||||
                return prevRhsNode;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            if (parent.type === "AssignmentExpression" &&
 | 
			
		||||
                isUnusedExpression(parent) &&
 | 
			
		||||
                id === parent.left &&
 | 
			
		||||
                !canBeUsedLater
 | 
			
		||||
            ) {
 | 
			
		||||
                return parent.right;
 | 
			
		||||
            }
 | 
			
		||||
            return null;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether a given function node is stored to somewhere or not.
 | 
			
		||||
         * If the function node is stored, the function can be used later.
 | 
			
		||||
         * @param {ASTNode} funcNode A function node to check.
 | 
			
		||||
         * @param {ASTNode} rhsNode The RHS node of the previous assignment.
 | 
			
		||||
         * @returns {boolean} `true` if under the following conditions:
 | 
			
		||||
         *      - the funcNode is assigned to a variable.
 | 
			
		||||
         *      - the funcNode is bound as an argument of a function call.
 | 
			
		||||
         *      - the function is bound to a property and the object satisfies above conditions.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isStorableFunction(funcNode, rhsNode) {
 | 
			
		||||
            let node = funcNode;
 | 
			
		||||
            let parent = funcNode.parent;
 | 
			
		||||
 | 
			
		||||
            while (parent && isInside(parent, rhsNode)) {
 | 
			
		||||
                switch (parent.type) {
 | 
			
		||||
                    case "SequenceExpression":
 | 
			
		||||
                        if (parent.expressions[parent.expressions.length - 1] !== node) {
 | 
			
		||||
                            return false;
 | 
			
		||||
                        }
 | 
			
		||||
                        break;
 | 
			
		||||
 | 
			
		||||
                    case "CallExpression":
 | 
			
		||||
                    case "NewExpression":
 | 
			
		||||
                        return parent.callee !== node;
 | 
			
		||||
 | 
			
		||||
                    case "AssignmentExpression":
 | 
			
		||||
                    case "TaggedTemplateExpression":
 | 
			
		||||
                    case "YieldExpression":
 | 
			
		||||
                        return true;
 | 
			
		||||
 | 
			
		||||
                    default:
 | 
			
		||||
                        if (STATEMENT_TYPE.test(parent.type)) {
 | 
			
		||||
 | 
			
		||||
                            /*
 | 
			
		||||
                             * If it encountered statements, this is a complex pattern.
 | 
			
		||||
                             * Since analyzing complex patterns is hard, this returns `true` to avoid false positive.
 | 
			
		||||
                             */
 | 
			
		||||
                            return true;
 | 
			
		||||
                        }
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                node = parent;
 | 
			
		||||
                parent = parent.parent;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return false;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether a given Identifier node exists inside of a function node which can be used later.
 | 
			
		||||
         *
 | 
			
		||||
         * "can be used later" means:
 | 
			
		||||
         * - the function is assigned to a variable.
 | 
			
		||||
         * - the function is bound to a property and the object can be used later.
 | 
			
		||||
         * - the function is bound as an argument of a function call.
 | 
			
		||||
         *
 | 
			
		||||
         * If a reference exists in a function which can be used later, the reference is read when the function is called.
 | 
			
		||||
         * @param {ASTNode} id An Identifier node to check.
 | 
			
		||||
         * @param {ASTNode} rhsNode The RHS node of the previous assignment.
 | 
			
		||||
         * @returns {boolean} `true` if the `id` node exists inside of a function node which can be used later.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isInsideOfStorableFunction(id, rhsNode) {
 | 
			
		||||
            const funcNode = astUtils.getUpperFunction(id);
 | 
			
		||||
 | 
			
		||||
            return (
 | 
			
		||||
                funcNode &&
 | 
			
		||||
                isInside(funcNode, rhsNode) &&
 | 
			
		||||
                isStorableFunction(funcNode, rhsNode)
 | 
			
		||||
            );
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether a given reference is a read to update itself or not.
 | 
			
		||||
         * @param {eslint-scope.Reference} ref A reference to check.
 | 
			
		||||
         * @param {ASTNode} rhsNode The RHS node of the previous assignment.
 | 
			
		||||
         * @returns {boolean} The reference is a read to update itself.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isReadForItself(ref, rhsNode) {
 | 
			
		||||
            const id = ref.identifier;
 | 
			
		||||
            const parent = id.parent;
 | 
			
		||||
 | 
			
		||||
            return ref.isRead() && (
 | 
			
		||||
 | 
			
		||||
                // self update. e.g. `a += 1`, `a++`
 | 
			
		||||
                (
 | 
			
		||||
                    (
 | 
			
		||||
                        parent.type === "AssignmentExpression" &&
 | 
			
		||||
                        parent.left === id &&
 | 
			
		||||
                        isUnusedExpression(parent) &&
 | 
			
		||||
                        !astUtils.isLogicalAssignmentOperator(parent.operator)
 | 
			
		||||
                    ) ||
 | 
			
		||||
                    (
 | 
			
		||||
                        parent.type === "UpdateExpression" &&
 | 
			
		||||
                        isUnusedExpression(parent)
 | 
			
		||||
                    )
 | 
			
		||||
                ) ||
 | 
			
		||||
 | 
			
		||||
                // in RHS of an assignment for itself. e.g. `a = a + 1`
 | 
			
		||||
                (
 | 
			
		||||
                    rhsNode &&
 | 
			
		||||
                    isInside(id, rhsNode) &&
 | 
			
		||||
                    !isInsideOfStorableFunction(id, rhsNode)
 | 
			
		||||
                )
 | 
			
		||||
            );
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determine if an identifier is used either in for-in or for-of loops.
 | 
			
		||||
         * @param {Reference} ref The reference to check.
 | 
			
		||||
         * @returns {boolean} whether reference is used in the for-in loops
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isForInOfRef(ref) {
 | 
			
		||||
            let target = ref.identifier.parent;
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
            // "for (var ...) { return; }"
 | 
			
		||||
            if (target.type === "VariableDeclarator") {
 | 
			
		||||
                target = target.parent.parent;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            if (target.type !== "ForInStatement" && target.type !== "ForOfStatement") {
 | 
			
		||||
                return false;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            // "for (...) { return; }"
 | 
			
		||||
            if (target.body.type === "BlockStatement") {
 | 
			
		||||
                target = target.body.body[0];
 | 
			
		||||
 | 
			
		||||
            // "for (...) return;"
 | 
			
		||||
            } else {
 | 
			
		||||
                target = target.body;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            // For empty loop body
 | 
			
		||||
            if (!target) {
 | 
			
		||||
                return false;
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return target.type === "ReturnStatement";
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Determines if the variable is used.
 | 
			
		||||
         * @param {Variable} variable The variable to check.
 | 
			
		||||
         * @returns {boolean} True if the variable is used
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function isUsedVariable(variable) {
 | 
			
		||||
            const functionNodes = getFunctionDefinitions(variable),
 | 
			
		||||
                isFunctionDefinition = functionNodes.length > 0;
 | 
			
		||||
            let rhsNode = null;
 | 
			
		||||
 | 
			
		||||
            return variable.references.some(ref => {
 | 
			
		||||
                if (isForInOfRef(ref)) {
 | 
			
		||||
                    return true;
 | 
			
		||||
                }
 | 
			
		||||
 | 
			
		||||
                const forItself = isReadForItself(ref, rhsNode);
 | 
			
		||||
 | 
			
		||||
                rhsNode = getRhsNode(ref, rhsNode);
 | 
			
		||||
 | 
			
		||||
                return (
 | 
			
		||||
                    isReadRef(ref) &&
 | 
			
		||||
                    !forItself &&
 | 
			
		||||
                    !(isFunctionDefinition && isSelfReference(ref, functionNodes))
 | 
			
		||||
                );
 | 
			
		||||
            });
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Checks whether the given variable is after the last used parameter.
 | 
			
		||||
         * @param {eslint-scope.Variable} variable The variable to check.
 | 
			
		||||
         * @returns {boolean} `true` if the variable is defined after the last
 | 
			
		||||
         * used parameter.
 | 
			
		||||
         */
 | 
			
		||||
        function isAfterLastUsedArg(variable) {
 | 
			
		||||
            const def = variable.defs[0];
 | 
			
		||||
            const params = sourceCode.getDeclaredVariables(def.node);
 | 
			
		||||
            const posteriorParams = params.slice(params.indexOf(variable) + 1);
 | 
			
		||||
 | 
			
		||||
            // If any used parameters occur after this parameter, do not report.
 | 
			
		||||
            return !posteriorParams.some(v => v.references.length > 0 || v.eslintUsed);
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        /**
 | 
			
		||||
         * Gets an array of variables without read references.
 | 
			
		||||
         * @param {Scope} scope an eslint-scope Scope object.
 | 
			
		||||
         * @param {Variable[]} unusedVars an array that saving result.
 | 
			
		||||
         * @returns {Variable[]} unused variables of the scope and descendant scopes.
 | 
			
		||||
         * @private
 | 
			
		||||
         */
 | 
			
		||||
        function collectUnusedVariables(scope, unusedVars) {
 | 
			
		||||
            const variables = scope.variables;
 | 
			
		||||
            const childScopes = scope.childScopes;
 | 
			
		||||
            let i, l;
 | 
			
		||||
 | 
			
		||||
            if (scope.type !== "global" || config.vars === "all") {
 | 
			
		||||
                for (i = 0, l = variables.length; i < l; ++i) {
 | 
			
		||||
                    const variable = variables[i];
 | 
			
		||||
 | 
			
		||||
                    // skip a variable of class itself name in the class scope
 | 
			
		||||
                    if (scope.type === "class" && scope.block.id === variable.identifiers[0]) {
 | 
			
		||||
                        continue;
 | 
			
		||||
                    }
 | 
			
		||||
 | 
			
		||||
                    // skip function expression names and variables marked with markVariableAsUsed()
 | 
			
		||||
                    if (scope.functionExpressionScope || variable.eslintUsed) {
 | 
			
		||||
                        continue;
 | 
			
		||||
                    }
 | 
			
		||||
 | 
			
		||||
                    // skip implicit "arguments" variable
 | 
			
		||||
                    if (scope.type === "function" && variable.name === "arguments" && variable.identifiers.length === 0) {
 | 
			
		||||
                        continue;
 | 
			
		||||
                    }
 | 
			
		||||
 | 
			
		||||
                    // explicit global variables don't have definitions.
 | 
			
		||||
                    const def = variable.defs[0];
 | 
			
		||||
 | 
			
		||||
                    if (def) {
 | 
			
		||||
                        const type = def.type;
 | 
			
		||||
                        const refUsedInArrayPatterns = variable.references.some(ref => ref.identifier.parent.type === "ArrayPattern");
 | 
			
		||||
 | 
			
		||||
                        // skip elements of array destructuring patterns
 | 
			
		||||
                        if (
 | 
			
		||||
                            (
 | 
			
		||||
                                def.name.parent.type === "ArrayPattern" ||
 | 
			
		||||
                                refUsedInArrayPatterns
 | 
			
		||||
                            ) &&
 | 
			
		||||
                            config.destructuredArrayIgnorePattern &&
 | 
			
		||||
                            config.destructuredArrayIgnorePattern.test(def.name.name)
 | 
			
		||||
                        ) {
 | 
			
		||||
                            continue;
 | 
			
		||||
                        }
 | 
			
		||||
 | 
			
		||||
                        // skip catch variables
 | 
			
		||||
                        if (type === "CatchClause") {
 | 
			
		||||
                            if (config.caughtErrors === "none") {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
 | 
			
		||||
                            // skip ignored parameters
 | 
			
		||||
                            if (config.caughtErrorsIgnorePattern && config.caughtErrorsIgnorePattern.test(def.name.name)) {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
                        }
 | 
			
		||||
 | 
			
		||||
                        if (type === "Parameter") {
 | 
			
		||||
 | 
			
		||||
                            // skip any setter argument
 | 
			
		||||
                            if ((def.node.parent.type === "Property" || def.node.parent.type === "MethodDefinition") && def.node.parent.kind === "set") {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
 | 
			
		||||
                            // if "args" option is "none", skip any parameter
 | 
			
		||||
                            if (config.args === "none") {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
 | 
			
		||||
                            // skip ignored parameters
 | 
			
		||||
                            if (config.argsIgnorePattern && config.argsIgnorePattern.test(def.name.name)) {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
 | 
			
		||||
                            // if "args" option is "after-used", skip used variables
 | 
			
		||||
                            if (config.args === "after-used" && astUtils.isFunction(def.name.parent) && !isAfterLastUsedArg(variable)) {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
                        } else {
 | 
			
		||||
 | 
			
		||||
                            // skip ignored variables
 | 
			
		||||
                            if (config.varsIgnorePattern && config.varsIgnorePattern.test(def.name.name)) {
 | 
			
		||||
                                continue;
 | 
			
		||||
                            }
 | 
			
		||||
                        }
 | 
			
		||||
                    }
 | 
			
		||||
 | 
			
		||||
                    if (!isUsedVariable(variable) && !isExported(variable) && !hasRestSpreadSibling(variable)) {
 | 
			
		||||
                        unusedVars.push(variable);
 | 
			
		||||
                    }
 | 
			
		||||
                }
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            for (i = 0, l = childScopes.length; i < l; ++i) {
 | 
			
		||||
                collectUnusedVariables(childScopes[i], unusedVars);
 | 
			
		||||
            }
 | 
			
		||||
 | 
			
		||||
            return unusedVars;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        //--------------------------------------------------------------------------
 | 
			
		||||
        // Public
 | 
			
		||||
        //--------------------------------------------------------------------------
 | 
			
		||||
 | 
			
		||||
        return {
 | 
			
		||||
            "Program:exit"(programNode) {
 | 
			
		||||
                const unusedVars = collectUnusedVariables(sourceCode.getScope(programNode), []);
 | 
			
		||||
 | 
			
		||||
                for (let i = 0, l = unusedVars.length; i < l; ++i) {
 | 
			
		||||
                    const unusedVar = unusedVars[i];
 | 
			
		||||
 | 
			
		||||
                    // Report the first declaration.
 | 
			
		||||
                    if (unusedVar.defs.length > 0) {
 | 
			
		||||
 | 
			
		||||
                        // report last write reference, https://github.com/eslint/eslint/issues/14324
 | 
			
		||||
                        const writeReferences = unusedVar.references.filter(ref => ref.isWrite() && ref.from.variableScope === unusedVar.scope.variableScope);
 | 
			
		||||
 | 
			
		||||
                        let referenceToReport;
 | 
			
		||||
 | 
			
		||||
                        if (writeReferences.length > 0) {
 | 
			
		||||
                            referenceToReport = writeReferences[writeReferences.length - 1];
 | 
			
		||||
                        }
 | 
			
		||||
 | 
			
		||||
                        context.report({
 | 
			
		||||
                            node: referenceToReport ? referenceToReport.identifier : unusedVar.identifiers[0],
 | 
			
		||||
                            messageId: "unusedVar",
 | 
			
		||||
                            data: unusedVar.references.some(ref => ref.isWrite())
 | 
			
		||||
                                ? getAssignedMessageData(unusedVar)
 | 
			
		||||
                                : getDefinedMessageData(unusedVar)
 | 
			
		||||
                        });
 | 
			
		||||
 | 
			
		||||
                    // If there are no regular declaration, report the first `/*globals*/` comment directive.
 | 
			
		||||
                    } else if (unusedVar.eslintExplicitGlobalComments) {
 | 
			
		||||
                        const directiveComment = unusedVar.eslintExplicitGlobalComments[0];
 | 
			
		||||
 | 
			
		||||
                        context.report({
 | 
			
		||||
                            node: programNode,
 | 
			
		||||
                            loc: astUtils.getNameLocationInGlobalDirectiveComment(sourceCode, directiveComment, unusedVar.name),
 | 
			
		||||
                            messageId: "unusedVar",
 | 
			
		||||
                            data: getDefinedMessageData(unusedVar)
 | 
			
		||||
                        });
 | 
			
		||||
                    }
 | 
			
		||||
                }
 | 
			
		||||
            }
 | 
			
		||||
        };
 | 
			
		||||
 | 
			
		||||
    }
 | 
			
		||||
};
 | 
			
		||||
		Reference in New Issue
	
	Block a user