Clarify browsers affected by nonEnumArgs and reduce code around hasEnumPrototype.

Former-commit-id: 587f755332accbca26dc1eb357a66d4f898aad88

build.js

@@ -805,29 +805,24 @@
       // match multi-line comment block (could be on a single line)
       '(?:\\n +/\\*[^*]*\\*+(?:[^/][^*]*\\*+)*/\\n)?' +
       // begin non-capturing group
-      '(?:' +
+      '( *)(?:' +
       // match a function declaration
-      '( *)function ' + funcName + '\\b[\\s\\S]+?\\n\\1}|' +
-      // match a variable declaration with `createIterator`
-      ' +var ' + funcName + ' *=.*?createIterator\\((?:{|[a-zA-Z])[\\s\\S]+?\\);|' +
+      'function ' + funcName + '\\b[\\s\\S]+?\\n\\1}|' +
       // match a variable declaration with function expression
-      '( *)var ' + funcName + ' *=.*?function[\\s\\S]+?\\n\\2};' +
+      'var ' + funcName + ' *=.*?function[\\s\\S]+?\\n\\1};' +
       // end non-capturing group
       ')\\n'
     ));
 
-    if (result) {
-      return result[0];
-    }
     // match variables that are explicitly defined as functions
-    result = source.match(RegExp(
+    result || (result = source.match(RegExp(
       // match multi-line comment block
       '(?:\\n +/\\*[^*]*\\*+(?:[^/][^*]*\\*+)*/)?\\n' +
-      // match a simple variable declaration
-      ' *var ' + funcName + ' *=.+?;\\n'
-    ));
+      // match simple variable declarations and those with `createIterator`
+      ' *var ' + funcName + ' *=(?:.+?|.*?createIterator\\([\\s\\S]+?\\));\\n'
+    )));
 
-    return /@type +Function/.test(result) ? result[0] : '';
+    return /@type +Function|function\s*\w*\(/.test(result) ? result[0] : '';
   }
 
   /**
@@ -953,12 +948,12 @@
     source = removeFromCreateIterator(source, 'shadowed');
 
     // remove `hasDontEnumBug` declaration and assignment
-    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var hasDontEnumBug;|.+?hasDontEnumBug *=.+/g, '');
+    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var hasDontEnumBug\b.*|.+?hasDontEnumBug *=.+/g, '');
 
     // remove `shadowed` variable
     source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var shadowed[\s\S]+?;\n/, '');
 
-    // remove JScript `[[DontEnum]]` fix from `iteratorTemplate`
+    // remove `hasDontEnumBug` from `iteratorTemplate`
     source = source.replace(getIteratorTemplate(source), function(match) {
       return match.replace(/(?: *\/\/.*\n)* *["']( *)<% *if *\(hasDontEnumBug[\s\S]+?["']\1<% *} *%>.+/, '');
     });
@@ -977,14 +972,16 @@
     source = removeFromCreateIterator(source, 'hasEnumPrototype');
 
     // remove `hasEnumPrototype` declaration and assignment
-    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var hasEnumPrototype;|.+?hasEnumPrototype *=.+/g, '');
+    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var hasEnumPrototype\b.*|.+?hasEnumPrototype *=.+/g, '');
 
-    // remove `prototype` [[Enumerable]] fix from `_.keys`
+    // remove `hasEnumPrototype` from `_.keys`
     source = source.replace(matchFunction(source, 'keys'), function(match) {
-      return match.replace(/(?:\s*\/\/.*)*(\s*return *).+?propertyIsEnumerable[\s\S]+?: */, '$1');
+      return match
+        .replace(/\(hasEnumPrototype[^)]+\)(?:\s*\|\|\s*)?/, '')
+        .replace(/\s*if *\(\s*\)[^}]+}/, '');
     });
 
-    // remove `prototype` [[Enumerable]] fix from `iteratorTemplate`
+    // remove `hasEnumPrototype` from `iteratorTemplate`
     source = source.replace(getIteratorTemplate(source), function(match) {
       return match
         .replace(/(?: *\/\/.*\n)* *["'] *(?:<% *)?if *\(hasEnumPrototype *(?:&&|\))[\s\S]+?<% *} *(?:%>|["']).+/g, '')
@@ -1025,7 +1022,7 @@
    */
   function removeIteratesOwnLast(source) {
     // remove `iteratesOwnLast` declaration and assignment
-    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var iteratesOwnLast;|.+?iteratesOwnLast *=.+/g, '');
+    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var iteratesOwnLast\b.*|.+?iteratesOwnLast *=.+/g, '');
 
     // remove `iteratesOwnLast` from `shimIsPlainObject`
     source = source.replace(matchFunction(source, 'shimIsPlainObject'), function(match) {
@@ -1117,9 +1114,16 @@
     source = removeFromCreateIterator(source, 'nonEnumArgs');
 
     // remove `nonEnumArgs` declaration and assignment
-    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var nonEnumArgs;|.+?nonEnumArgs *=.+/g, '');
+    source = source.replace(/(?:\n +\/\*[^*]*\*+(?:[^\/][^*]*\*+)*\/)?\n *var nonEnumArgs\b.*|.+?nonEnumArgs *=.+/g, '');
 
-    // remove `nonEnumArgs` fix from `iteratorTemplate`
+    // remove `nonEnumArgs` from `_.keys`
+    source = source.replace(matchFunction(source, 'keys'), function(match) {
+      return match
+        .replace(/(?:\s*\|\|\s*)?\(nonEnumArgs[^)]+\)\)/, '')
+        .replace(/\s*if *\(\s*\)[^}]+}/, '');
+    });
+
+    // remove `nonEnumArgs` from `iteratorTemplate`
     source = source.replace(getIteratorTemplate(source), function(match) {
       return match
         .replace(/(?: *\/\/.*\n)*( *["'] *)<% *} *else *if *\(nonEnumArgs[\s\S]+?(\1<% *} *%>.+)/, '$2')

build/pre-compile.js

@@ -26,7 +26,6 @@
     'objectTypes',
     'ownIndex',
     'ownProps',
-    'propertyIsEnumerable',
     'result',
     'skipProto',
     'source',

lodash.js

@@ -85,7 +85,6 @@
       getPrototypeOf = reNative.test(getPrototypeOf = Object.getPrototypeOf) && getPrototypeOf,
       hasOwnProperty = objectRef.hasOwnProperty,
       push = arrayRef.push,
-      propertyIsEnumerable = objectRef.propertyIsEnumerable,
       toString = objectRef.toString;
 
   /* Native method shortcuts for methods with the same name as other `lodash` methods */
@@ -153,7 +152,7 @@
   var hasObjectSpliceBug = (hasObjectSpliceBug = { '0': 1, 'length': 1 },
     arrayRef.splice.call(hasObjectSpliceBug, 0, 1), hasObjectSpliceBug[0]);
 
-  /** Detect if an `arguments` object's indexes are non-enumerable (IE < 9) */
+  /** Detect if `arguments` object indexes are non-enumerable (Firefox < 4, IE < 9, Safari < 5.1) */
   var nonEnumArgs = true;
 
   (function() {
@@ -164,7 +163,7 @@
     for (prop in arguments) { nonEnumArgs = !prop; }
 
     hasDontEnumBug = !/valueOf/.test(props);
-    hasEnumPrototype = propertyIsEnumerable.call(ctor, 'prototype');
+    hasEnumPrototype = ctor.propertyIsEnumerable('prototype');
     iteratesOwnLast = props[0] != 'x';
   }(1));
 
@@ -392,8 +391,7 @@
 
     // avoid iterating over `prototype` properties in older Firefox, Opera, and Safari
     '  <% if (hasEnumPrototype) { %>\n' +
-    "  var skipProto = typeof iterable == 'function' && \n" +
-    "    propertyIsEnumerable.call(iterable, 'prototype');\n" +
+    "  var skipProto = typeof iterable == 'function';\n" +
     '  <% } %>' +
 
     // iterate own properties using `Object.keys` if it's fast
@@ -710,13 +708,13 @@
     // create the function factory
     var factory = Function(
         'createCallback, hasOwnProperty, isArguments, isArray, isString, ' +
-        'objectTypes, nativeKeys, propertyIsEnumerable',
+        'objectTypes, nativeKeys',
       'return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}'
     );
     // return the compiled function
     return factory(
       createCallback, hasOwnProperty, isArguments, isArray, isString,
-      objectTypes, nativeKeys, propertyIsEnumerable
+      objectTypes, nativeKeys
     );
   }
 
@@ -728,6 +726,7 @@
    * iteration early by explicitly returning `false`.
    *
    * @private
+   * @type Function
    * @param {Array|Object|String} collection The collection to iterate over.
    * @param {Function} [callback=identity] The function called per iteration.
    * @param {Mixed} [thisArg] The `this` binding of `callback`.
@@ -855,6 +854,7 @@
    *
    * @static
    * @memberOf _
+   * @type Function
    * @category Objects
    * @param {Object} object The object to iterate over.
    * @param {Function} [callback=identity] The function called per iteration.
@@ -887,6 +887,7 @@
    *
    * @static
    * @memberOf _
+   * @type Function
    * @category Objects
    * @param {Object} object The object to iterate over.
    * @param {Function} [callback=identity] The function called per iteration.
@@ -937,10 +938,14 @@
    * // => ['one', 'two', 'three'] (order is not guaranteed)
    */
   var keys = !nativeKeys ? shimKeys : function(object) {
-    // avoid iterating over the `prototype` property
-    return hasEnumPrototype && typeof object == 'function' && propertyIsEnumerable.call(object, 'prototype')
-      ? shimKeys(object)
-      : (isObject(object) ? nativeKeys(object) : []);
+    if (!isObject(object)) {
+      return [];
+    }
+    if ((hasEnumPrototype && typeof object == 'function') ||
+        (nonEnumArgs && object.length && isArguments(object))) {
+      return shimKeys(object);
+    }
+    return nativeKeys(object);
   };
 
   /**
@@ -1027,6 +1032,7 @@
    *
    * @static
    * @memberOf _
+   * @type Function
    * @alias extend
    * @category Objects
    * @param {Object} object The destination object.
@@ -1220,6 +1226,7 @@
    *
    * @static
    * @memberOf _
+   * @type Function
    * @category Objects
    * @param {Object} object The destination object.
    * @param {Object} [source1, source2, ...] The source objects.