New: no-invalid-regexp allows custom flags (fixes eslint#5249)

afahim · Feb 21, 2016 · bf16380 · bf16380
1 parent 40fec58
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Showing 3 changed files with 45 additions and 1 deletion.
diff --git a/docs/rules/no-invalid-regexp.md b/docs/rules/no-invalid-regexp.md
@@ -32,6 +32,24 @@ this.RegExp('[')
 
 ECMAScript 6 adds the "u" ([unicode](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-get-regexp.prototype.unicode)) and "y" ([sticky](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-get-regexp.prototype.sticky)) flags. You can enable these to be recognized as valid by setting the ECMAScript version to 6 in your [ESLint configuration](../user-guide/configuring).
 
+
+## Options
+
+If you want to allow additional constructor flags for any reason, you can specify them using an `allowConstructorFlags` option in `.eslintrc`. These flags will then be ignored by the rule regardless of the `ecmaVersion` setting.
+
+### `allowConstructorFlags`
+
+This takes in an array of flags. With this option, the following patterns aren't considered problems:
+
+```js
+/*eslint no-invalid-regexp: [2, {"allowConstructorFlags": ["u", "y"]}]*/
+
+new RegExp('.', 'y')
+
+new RegExp('.', 'yu')
+```
+
+
 ## Further Reading
 
 * [Annotated ES5 §7.8.5 - Regular Expression Literals](http://es5.github.io/#x7.8.5)
diff --git a/lib/rules/no-invalid-regexp.js b/lib/rules/no-invalid-regexp.js
@@ -17,6 +17,13 @@ var espree = require("espree");
 
 module.exports = function(context) {
 
+    var options = context.options[0],
+        allowedFlags = "";
+
+    if (options && options.allowConstructorFlags) {
+        allowedFlags = options.allowConstructorFlags.join("");
+    }
+
     /**
      * Check if node is a string
      * @param {ASTNode} node node to evaluate
@@ -37,6 +44,10 @@ module.exports = function(context) {
         if (node.callee.type === "Identifier" && node.callee.name === "RegExp" && isString(node.arguments[0])) {
             var flags = isString(node.arguments[1]) ? node.arguments[1].value : "";
 
+            if (allowedFlags) {
+                flags = flags.replace(new RegExp("[" + allowedFlags + "]", "gi"), "");
+            }
+
             try {
                 void new RegExp(node.arguments[0].value);
             } catch (e) {
@@ -62,4 +73,15 @@ module.exports = function(context) {
 
 };
 
-module.exports.schema = [];
+module.exports.schema = [{
+    "type": "object",
+    "properties": {
+        "allowConstructorFlags": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        }
+    },
+    "additionalProperties": false
+}];
diff --git a/tests/lib/rules/no-invalid-regexp.js b/tests/lib/rules/no-invalid-regexp.js
@@ -22,6 +22,10 @@ ruleTester.run("no-invalid-regexp", rule, {
         "new RegExp",
         "new RegExp('.', 'im')",
         "global.RegExp('\\\\')",
+        { code: "new RegExp('.', 'y')", options: [{ allowConstructorFlags: ["y"] }]},
+        { code: "new RegExp('.', 'u')", options: [{ allowConstructorFlags: ["U"] }]},
+        { code: "new RegExp('.', 'yu')", options: [{ allowConstructorFlags: ["y", "u"] }]},
+        { code: "new RegExp('\/', 'yu')", options: [{ allowConstructorFlags: ["y", "u"] }]},
         { code: "new RegExp('.', 'y')", parserOptions: { ecmaVersion: 6 }},
         { code: "new RegExp('.', 'u')", parserOptions: { ecmaVersion: 6 }},
         { code: "new RegExp('.', 'yu')", parserOptions: { ecmaVersion: 6 }},