Add _.conformsTo.

lodash.js

@@ -2413,28 +2413,39 @@
      * @returns {Function} Returns the new spec function.
      */
     function baseConforms(source) {
-      var props = keys(source),
-          length = props.length;
-
+      var props = keys(source);
       return function(object) {
-        if (object == null) {
-          return !length;
-        }
-        var index = length;
-        while (index--) {
-          var key = props[index],
-              predicate = source[key],
-              value = object[key];
-
-          if ((value === undefined &&
-              !(key in Object(object))) || !predicate(value)) {
-            return false;
-          }
-        }
-        return true;
+        return baseConformsTo(object, source, props);
       };
     }
 
+    /**
+     * The base implementation of `_.conformsTo` which accepts `props` to check.
+     *
+     * @private
+     * @param {Object} object The object to inspect.
+     * @param {Object} source The object of property predicates to conform to.
+     * @returns {boolean} Returns `true` if `object` conforms, else `false`.
+     */
+    function baseConformsTo(object, source, props) {
+      var length = props.length;
+      if (object == null) {
+        return !length;
+      }
+      var index = length;
+      while (index--) {
+        var key = props[index],
+            predicate = source[key],
+            value = object[key];
+
+        if ((value === undefined &&
+            !(key in Object(object))) || !predicate(value)) {
+          return false;
+        }
+      }
+      return true;
+    }
+
     /**
      * The base implementation of `_.create` without support for assigning
      * properties to the created object.
@@ -10470,6 +10481,32 @@
       return baseClone(value, true, true, customizer);
     }
 
+    /**
+     * Checks if `object` conforms to `source` by invoking the predicate properties
+     * of `source` with the corresponding property values of `object`. This method
+     * is equivalent to a `_.conforms` function when `source` is partially applied.
+     *
+     * @static
+     * @memberOf _
+     * @since 4.14.0
+     * @category Lang
+     * @param {Object} object The object to inspect.
+     * @param {Object} source The object of property predicates to conform to.
+     * @returns {boolean} Returns `true` if `object` conforms, else `false`.
+     * @example
+     *
+     * var object = { 'user': 'fred', 'age': 40 };
+     *
+     * _.conformsTo(object, { 'age': function(n) { return n > 38; } });
+     * // => true
+     *
+     * _.conformsTo(object, { 'age': function(n) { return n < 38; } });
+     * // => false
+     */
+    function conformsTo(object, source) {
+      return source == null || baseConformsTo(object, source, keys(source));
+    }
+
     /**
      * Performs a
      * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
@@ -16003,6 +16040,7 @@
     lodash.cloneDeep = cloneDeep;
     lodash.cloneDeepWith = cloneDeepWith;
     lodash.cloneWith = cloneWith;
+    lodash.conformsTo = conformsTo;
     lodash.deburr = deburr;
     lodash.defaultTo = defaultTo;
     lodash.divide = divide;

test/test.js

@@ -26597,7 +26597,7 @@
     var acceptFalsey = lodashStable.difference(allMethods, rejectFalsey);
 
     QUnit.test('should accept falsey arguments', function(assert) {
-      assert.expect(315);
+      assert.expect(316);
 
       var arrays = lodashStable.map(falsey, stubArray);