lodash: changed _.mixin() method

lodash/lodash-tests.ts

@@ -1652,12 +1652,6 @@ var testAttempFn: TestAttemptFn;
 result = <TResult|Error>_.attempt<TResult>(testAttempFn);
 result = <TResult|Error>_(testAttempFn).attempt<TResult>();
 
-_.mixin({
-    'capitalize': function (string) {
-        return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
-    }
-});
-
 var lodash = <typeof _>_.noConflict();
 
 result = <number>_.random(0, 5);
@@ -1939,6 +1933,21 @@ result = <number>(_.methodOf<number>(TestMethodOfObject, 1, 2))(['a', '0']);
 result = <number>(_(TestMethodOfObject).methodOf<number>(1, 2).value())('a[0]');
 result = <number>(_(TestMethodOfObject).methodOf<number>(1, 2).value())(['a', '0']);
 
+// _.mixin
+{
+    let testMixinSource: _.Dictionary<Function>;
+    let testMixinOptions: {chain?: boolean;}
+    let result: TResult;
+    result = _.mixin<TResult, Object>({}, testMixinSource);
+    result = _.mixin<TResult, Object>({}, testMixinSource, testMixinOptions);
+    result = _.mixin<TResult>(testMixinSource);
+    result = _.mixin<TResult>(testMixinSource, testMixinOptions);
+    result = _({}).mixin<TResult>(testMixinSource).value();
+    result = _({}).mixin<TResult>(testMixinSource, testMixinOptions).value();
+    result = _(testMixinSource).mixin<TResult>().value();
+    result = _(testMixinSource).mixin<TResult>(testMixinOptions).value();
+}
+
 // _.uniqueId
 result = <string>_.uniqueId();
 result = <string>_.uniqueId('');

lodash/lodash.d.ts

@@ -8151,12 +8151,54 @@ declare module _ {
     }
 
     //_.mixin
+    interface MixinOptions {
+        chain?: boolean;
+    }
+
     interface LoDashStatic {
         /**
-        * Adds function properties of a source object to the lodash function and chainable wrapper.
-        * @param object The object of function properties to add to lodash.
-        **/
-        mixin(object?: Dictionary<(value: any) => any>): void;
+         * Adds all own enumerable function properties of a source object to the destination object. If object is a
+         * function then methods are added to its prototype as well.
+         *
+         * Note: Use _.runInContext to create a pristine lodash function to avoid conflicts caused by modifying
+         * the original.
+         *
+         * @param object The destination object.
+         * @param source The object of functions to add.
+         * @param options The options object.
+         * @param options.chain Specify whether the functions added are chainable.
+         * @return Returns object.
+         */
+        mixin<TResult, TObject>(
+            object: TObject,
+            source: Dictionary<Function>,
+            options?: MixinOptions
+        ): TResult;
+
+        /**
+         * @see _.mixin
+         */
+        mixin<TResult>(
+            source: Dictionary<Function>,
+            options?: MixinOptions
+        ): TResult;
+    }
+
+    interface LoDashObjectWrapper<T> {
+        /**
+         * @see _.mixin
+         */
+        mixin<TResult>(
+            source: Dictionary<Function>,
+            options?: MixinOptions
+        ): LoDashObjectWrapper<TResult>;
+
+        /**
+         * @see _.mixin
+         */
+        mixin<TResult>(
+            options?: MixinOptions
+        ): LoDashObjectWrapper<TResult>;
     }
 
     //_.noConflict