Allow _.omit and _.pick to work as a callback for _.map when combined with _.partialRight.

lodash.js

@@ -2392,8 +2392,7 @@
         callback = isShallow;
         isShallow = false;
 
-        // allows working with functions like `_.map` without using
-        // their `index` argument as a callback
+        // enables use as a callback for functions like `_.map`
         if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === array) {
           callback = null;
         }
@@ -3074,8 +3073,7 @@
         callback = isSorted;
         isSorted = false;
 
-        // allows working with functions like `_.map` without using
-        // their `index` argument as a callback
+        // enables use as a callback for functions like `_.map`
         if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === array) {
           callback = null;
         }
@@ -3358,8 +3356,7 @@
           length = props.length,
           type = typeof guard;
 
-      // allows working with functions like `_.map` without using
-      // their `index` arguments
+      // enables use as a callback for functions like `_.map`
       if ((type == 'number' || type == 'string') && args[2] && args[2][guard] === collection) {
         length = 1;
       }
@@ -3996,8 +3993,7 @@
           result = computed,
           type = typeof callback;
 
-      // allows working with functions like `_.map` without using
-      // their `index` argument as a callback
+      // enables use as a callback for functions like `_.map`
       if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === collection) {
         callback = null;
       }
@@ -4072,8 +4068,7 @@
           result = computed,
           type = typeof callback;
 
-      // allows working with functions like `_.map` without using
-      // their `index` argument as a callback
+      // enables use as a callback for functions like `_.map`
       if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === collection) {
         callback = null;
       }
@@ -4263,8 +4258,7 @@
      * @category Collections
      * @param {Array|Object|string} collection The collection to sample.
      * @param {number} [n] The number of elements to sample.
-     * @param- {Object} [guard] Allows working with functions like `_.map`
-     *  without using their `index` arguments as `n`.
+     * @param- {Object} [guard] Enables use as a callback for functions like `_.map`.
      * @returns {*} Returns the random sample(s) of `collection`.
      * @example
      *
@@ -5235,8 +5229,7 @@
           argsLength = args.length,
           type = typeof guard;
 
-      // allows working with functions like `_.reduce` without using their
-      // `key` and `object` arguments as sources
+      // enables use as a callback for functions like `_.reduce`
       if ((type == 'number' || type == 'string') && args[3] && args[3][guard] === source) {
         argsLength = 2;
       }
@@ -5317,8 +5310,7 @@
         callback = isDeep;
         isDeep = false;
 
-        // allows working with functions like `_.map` without using
-        // their `index` argument as a callback
+        // enables use as a callback for functions like `_.map`
         if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === value) {
           callback = null;
         }
@@ -5418,8 +5410,7 @@
      * @category Objects
      * @param {Object} object The destination object.
      * @param {...Object} [source] The source objects.
-     * @param- {Object} [guard] Allows working with functions like `_.reduce`
-     *   without using their `key` and `object` arguments as sources.
+     * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`.
      * @returns {Object} Returns the destination object.
      * @example
      *
@@ -5432,8 +5423,7 @@
           argsLength = args.length,
           type = typeof guard;
 
-      // allows working with functions like `_.reduce` without using their
-      // `key` and `object` arguments as sources
+      // enables use as a callback for functions like `_.reduce`
       if ((type == 'number' || type == 'string') && args[3] && args[3][guard] === source) {
         argsLength = 2;
       }
@@ -6335,8 +6325,7 @@
           length = args.length,
           type = typeof guard;
 
-      // allows working with functions like `_.reduce` without using their
-      // `key` and `object` arguments as sources
+      // enables use as a callback for functions like `_.reduce`
       if ((type == 'number' || type == 'string') && args[3] && args[3][guard] === source) {
         length = 2;
       }
@@ -6371,8 +6360,9 @@
      * @memberOf _
      * @category Objects
      * @param {Object} object The source object.
-     * @param {Function|...string|string[]} [callback] The properties to omit or the
-     *  function called per iteration.
+     * @param {Function|...string|string[]} [callback] The function called per
+     *  iteration or property names to omit, specified as individual property
+     *  names or arrays of property names.
      * @param {*} [thisArg] The `this` binding of `callback`.
      * @returns {Object} Returns an object without the omitted properties.
      * @example
@@ -6386,16 +6376,31 @@
      * // => { 'name': 'fred' }
      */
     function omit(object, callback, thisArg) {
-      var result = {};
-      if (typeof callback != 'function') {
+      var result = {},
+          type = typeof callback;
+
+      if (type != 'function') {
+        // enables use as a callback for functions like `_.map`
+        // when combined with `_.partialRight`
+        var args = arguments;
+        if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === object) {
+          args = slice(args);
+          splice.call(args, 1, 2);
+        }
+        var omitProps = baseFlatten(args, true, false, 1),
+            length = omitProps.length;
+
+        while (length--) {
+          omitProps[length] = String(omitProps[length]);
+        }
         var props = [];
         baseForIn(object, function(value, key) {
           props.push(key);
         });
-        props = baseDifference(props, baseFlatten(arguments, true, false, 1));
 
-        var index = -1,
-            length = props.length;
+        var index = -1;
+        props = baseDifference(props, omitProps);
+        length = props.length;
 
         while (++index < length) {
           var key = props[index];
@@ -6467,10 +6472,19 @@
      * // => { 'name': 'fred' }
      */
     function pick(object, callback, thisArg) {
-      var result = {};
-      if (typeof callback != 'function') {
+      var result = {},
+          type = typeof callback;
+
+      if (type != 'function') {
+        // enables use as a callback for functions like `_.map`
+        // when combined with `_.partialRight`
+        var args = arguments;
+        if ((type == 'number' || type == 'string') && thisArg && thisArg[callback] === object) {
+          args = slice(args);
+          splice.call(args, 1, 2);
+        }
         var index = -1,
-            props = baseFlatten(arguments, true, false, 1),
+            props = baseFlatten(args, true, false, 1),
             length = isObject(object) ? props.length : 0;
 
         while (++index < length) {