Merge pull request #5422 from chrootsu/lodash-thru

lodash: added _.thru() method

lodash/lodash-tests.ts

@@ -403,9 +403,45 @@ result = <number[]>_([1, 2]).zipWith<number>(testZipWithFn, any).value();
 result = <number[]>_([1, 2]).zipWith<number>([1, 2], testZipWithFn, any).value();
 result = <number[]>_([1, 2]).zipWith<number>([1, 2], [1, 2], [1, 2], [1, 2], [1, 2], testZipWithFn, any).value();
 
-// /* *************
-//  * Collections *
-//  ************* */
+/*********
+ * Chain *
+ *********/
+
+// _.thru
+{
+    let result: number;
+    result = _.thru<number, number>(1, (value: number) => value);
+    result = _.thru<number, number>(1, (value: number) => value, any);
+}
+{
+    let result: _.LoDashWrapper<number>;
+    result = _(1).thru<number>((value: number) => value);
+    result = _(1).thru<number>((value: number) => value, any);
+}
+{
+    let result: _.LoDashWrapper<string>;
+    result = _('').thru<string>((value: string) => value);
+    result = _('').thru<string>((value: string) => value, any);
+}
+{
+    let result: _.LoDashWrapper<boolean>;
+    result = _(true).thru<boolean>((value: boolean) => value);
+    result = _(true).thru<boolean>((value: boolean) => value, any);
+}
+{
+    let result: _.LoDashObjectWrapper<any>;
+    result = _({}).thru<Object>((value: Object) => value);
+    result = _({}).thru<Object>((value: Object) => value, any);
+}
+{
+    let result: _.LoDashArrayWrapper<number>;
+    result = _([1, 2, 3]).thru<number>((value: number[]) => value);
+    result = _([1, 2, 3]).thru<number>((value: number[]) => value, any);
+}
+
+/**************
+ * Collection *
+ **************/
 
 result = <string[]>_.at(['a', 'b', 'c', 'd', 'e'], [0, 2, 4]);
 result = <string[]>_.at(['moe', 'larry', 'curly'], 0, 2);

lodash/lodash.d.ts

@@ -2000,9 +2000,65 @@ declare module _ {
         zipWith<TResult>(...args: any[]): LoDashArrayWrapper<TResult>;
     }
 
-    /* *************
-     * Collections *
-     ************* */
+    /*********
+     * Chain *
+     *********/
+
+    //_.thru
+    interface LoDashStatic {
+        /**
+         * This method is like _.tap except that it returns the result of interceptor.
+         * @param value The value to provide to interceptor.
+         * @param interceptor The function to invoke.
+         * @param thisArg The this binding of interceptor.
+         * @return Returns the result of interceptor.
+         */
+        thru<T, TResult>(
+            value: T,
+            interceptor: (value: T) => TResult,
+            thisArg?: any): TResult;
+    }
+
+    interface LoDashWrapperBase<T, TWrapper> {
+        /**
+         * @see _.thru
+         */
+        thru<TResult extends number>(
+            interceptor: (value: T) => TResult,
+            thisArg?: any): LoDashWrapper<TResult>;
+
+        /**
+         * @see _.thru
+         */
+        thru<TResult extends string>(
+            interceptor: (value: T) => TResult,
+            thisArg?: any): LoDashWrapper<TResult>;
+
+        /**
+         * @see _.thru
+         */
+        thru<TResult extends boolean>(
+            interceptor: (value: T) => TResult,
+            thisArg?: any): LoDashWrapper<TResult>;
+
+        /**
+         * @see _.thru
+         */
+        thru<TResult extends Object>(
+            interceptor: (value: T) => TResult,
+            thisArg?: any): LoDashObjectWrapper<TResult>;
+
+        /**
+         * @see _.thru
+         */
+        thru<TResult>(
+            interceptor: (value: T) => TResult[],
+            thisArg?: any): LoDashArrayWrapper<TResult>;
+    }
+
+    /**************
+     * Collection *
+     **************/
 
     //_.at
     interface LoDashStatic {