Merge pull request #5202 from chrootsu/lodash-before

lodash: added _.before() method

lodash/lodash-tests.ts

@@ -769,6 +769,24 @@ var testBackflowAddFn = (n: number, m: number) => n + m;
 result = <number>_.backflow<(n: number, m: number) => number>(testBackflowSquareFn, testBackflowAddFn)(1, 2);
 result = <number>_(testBackflowSquareFn).backflow<(n: number, m: number) => number>(testBackflowAddFn).value()(1, 2);
 
+// _.before
+var testBeforeFn = ((n: number) => () => ++n)(0);
+var testBeforeResultFn = <() => number>_.before<() => number>(3, testBeforeFn);
+result = <number>testBeforeResultFn();
+// → 1
+result = <number>testBeforeResultFn();
+// → 2
+result = <number>testBeforeResultFn();
+// → 2
+var testBeforeFn = ((n: number) => () => ++n)(0);
+var testBeforeResultFn = <() => number>_(3).before<() => number>(testBeforeFn);
+result = <number>testBeforeResultFn();
+// → 1
+result = <number>testBeforeResultFn();
+// → 2
+result = <number>testBeforeResultFn();
+// → 2
+
 var funcBind = function(greeting: string, punctuation: string) { return greeting + ' ' + this.user + punctuation; };
 var funcBound1: (punctuation: string) => any = _.bind(funcBind, { 'name': 'moe' }, 'hi');
 funcBound1('!');

lodash/lodash.d.ts

@@ -5183,6 +5183,26 @@ declare module _ {
         backflow<TResult extends Function>(...funcs: Function[]): LoDashObjectWrapper<TResult>;
     }
 
+    //_.before
+    interface LoDashStatic {
+        /**
+         * Creates a function that invokes func, with the this binding and arguments of the created function, while
+         * it is called less than n times. Subsequent calls to the created function return the result of the last func
+         * invocation.
+         * @param n The number of calls at which func is no longer invoked.
+         * @param func The function to restrict.
+         * @return Returns the new restricted function.
+         */
+        before<TFunc extends Function>(n: number, func: TFunc): TFunc;
+    }
+
+    interface LoDashWrapper<T> {
+        /**
+         * @sed _.before
+         */
+        before<TFunc extends Function>(func: TFunc): TFunc;
+    }
+
     //_.bind
     interface LoDashStatic {
         /**