Adding mechanism to test command-line variables

run-tests

@@ -10,9 +10,16 @@ for TEST in tests/*.expected; do
     BASE="${TEST%.expected}"
 
     echo -n "$BASE ... "
-    echo "Do not read this input" | (
-        . "${BASE}.env"
-        mo "${BASE}.template"
+
+    (
+        if [[ -f "${BASE}.sh" ]]; then
+            # Run a shell script if one exists
+            "${BASE}.sh"
+        else
+            # Fall back to using .env and .template
+            . "${BASE}.env"
+            echo "Do not read this input" | mo "${BASE}.template"
+        fi
     ) | diff -wU5 - "${TEST}" > "${BASE}.diff"
 
     if [[ $? -ne 0 ]]; then

tests/help.expected

@@ -0,0 +1,8 @@
+Mo is a mustache template rendering software written in bash.  It inserts
+environment variables into templates.
+
+Simply put, mo will change {{VARIABLE}} into the value of that
+environment variable.  You can use {{#VARIABLE}}content{{/VARIABLE}} to
+conditionally display content or iterate over the values of an array.
+
+Learn more about mustache templates at https://mustache.github.io/

tests/help.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+cd "${0%/*}"
+../mo --help