disallowDanglingUnderscores: do not rewrite __proto__ property

Fixes #2026
jscs-dev · Dec 18, 2015 · 4158f1a · 4158f1a
1 parent 89b0440
commit 4158f1a
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Showing 2 changed files with 20 additions and 5 deletions.
diff --git a/lib/rules/disallow-dangling-underscores.js b/lib/rules/disallow-dangling-underscores.js
@@ -83,10 +83,7 @@ module.exports.prototype = {
             identifiers = (identifiers.allExcept).concat(defaultIdentifiers);
         }
 
-        this._identifierIndex = {};
-        for (var i = 0, l = identifiers.length; i < l; i++) {
-            this._identifierIndex[identifiers[i]] = true;
-        }
+        this._identifierIndex = identifiers;
     },
 
     getOptionName: function() {
@@ -98,8 +95,9 @@ module.exports.prototype = {
 
         file.iterateTokensByType('Identifier', function(token) {
             var value = token.value;
+
             if ((value[0] === '_' || value.slice(-1) === '_') &&
-                !allowedIdentifiers[value]
+                allowedIdentifiers.indexOf(value) < 0
             ) {
                 errors.add(
                     'Invalid dangling underscore found',

diff --git a/test/specs/rules/disallow-dangling-underscores.js b/test/specs/rules/disallow-dangling-underscores.js
@@ -15,6 +15,23 @@ describe('rules/disallow-dangling-underscores', function() {
                 checker.configure({ disallowDanglingUnderscores: { allExcept: true } });
             }).to.throw();
         });
+
+        it('should not set property `__proto__` to `true` value (#2026)', function() {
+            var old = Object.getOwnPropertyDescriptor(Object.prototype,'__proto__');
+
+            Object.defineProperty(Object.prototype, '__proto__', {
+                set: function(newProto) {
+                    expect(newProto).to.not.equal(true);
+                }
+            });
+
+            expect(function() {
+                checker.configure({ disallowDanglingUnderscores: true });
+            }).to.not.throw();
+
+            // Beware, if assertion will be incorrect it will break all the subsequent tests
+            Object.defineProperty(Object.prototype, '__proto__', old);
+        });
     });
 
     describe('option value true', function() {