(feature) Add _.flip and _.unary

lodash/lodash-tests.ts

@@ -4627,8 +4627,7 @@ module TestNow {
 /*************
  * Functions *
  *************/
-
-// _after
+// _.after
 module TestAfter {
     interface Func {
         (a: string, b: number): boolean;
@@ -5080,6 +5079,33 @@ module TestDelay {
     }
 }
 
+// _.flip
+module TestFlip {
+    interface Func {
+        (a: number, b: string): boolean;
+    }
+
+    let func: Func;
+
+    {
+        let result: Func;
+
+        result = _.flip(func);
+    }
+
+    {
+        let result: _.LoDashImplicitObjectWrapper<Func>;
+
+        result = _(func).flip();
+    }
+
+    {
+        let result: _.LoDashExplicitObjectWrapper<Func>;
+
+        result = _(func).chain().flip();
+    }
+}
+
 // _.flow
 module TestFlow {
     let Fn1: (n: number) => number;
@@ -5395,6 +5421,33 @@ module TestThrottle {
     }
 }
 
+// _.unary
+module TestUnary {
+    interface Func {
+        (a: number, b: string): boolean;
+    }
+
+    let func: Func;
+
+    {
+        let result: Func;
+
+        result = _.unary(func);
+    }
+
+    {
+        let result: _.LoDashImplicitObjectWrapper<Func>;
+
+        result = _(func).unary();
+    }
+
+    {
+        let result: _.LoDashExplicitObjectWrapper<Func>;
+
+        result = _(func).chain().unary();
+    }
+}
+
 // _.wrap
 module TestWrap {
     type SampleValue = {a: number; b: string; c: boolean}

lodash/lodash.d.ts

@@ -140,12 +140,12 @@ added 4 math methods:
 - [ ] _.sumBy
 
 added 2 function methods:
-- [ ] _.flip &
-- [ ] _.unary
+- [x] _.flip
+- [x] _.unary
 
 added 2 number methods:
-- [ ] _.clamp &
-- [ ] _.subtract
+- [x] _.clamp
+- [x] _.subtract
 
 added chain method:
 - [ ] _.next
@@ -8366,6 +8366,41 @@ declare module _ {
         ): LoDashExplicitWrapper<number>;
     }
 
+    interface LoDashStatic {
+        /**
+         * Creates a function that invokes `func` with arguments reversed.
+         *
+         * @static
+         * @memberOf _
+         * @category Function
+         * @param {Function} func The function to flip arguments for.
+         * @returns {Function} Returns the new function.
+         * @example
+         *
+         * var flipped = _.flip(function() {
+         *   return _.toArray(arguments);
+         * });
+         *
+         * flipped('a', 'b', 'c', 'd');
+         * // => ['d', 'c', 'b', 'a']
+         */
+        flip<T extends Function>(func: T): T;
+    }
+
+    interface LoDashImplicitObjectWrapper<T> {
+        /**
+         * @see _.flip
+         */
+        flip(): LoDashImplicitObjectWrapper<T>;
+    }
+
+    interface LoDashExplicitObjectWrapper<T> {
+        /**
+         * @see _.flip
+         */
+        flip(): LoDashExplicitObjectWrapper<T>;
+    }
+
     //_.flow
     interface LoDashStatic {
         /**
@@ -8846,6 +8881,39 @@ declare module _ {
         ): LoDashExplicitObjectWrapper<T & Cancelable>;
     }
 
+    //_.unary
+    interface LoDashStatic {
+        /**
+         * Creates a function that accepts up to one argument, ignoring any
+         * additional arguments.
+         *
+         * @static
+         * @memberOf _
+         * @category Function
+         * @param {Function} func The function to cap arguments for.
+         * @returns {Function} Returns the new function.
+         * @example
+         *
+         * _.map(['6', '8', '10'], _.unary(parseInt));
+         * // => [6, 8, 10]
+         */
+        unary<T extends Function>(func: T): T;
+    }
+
+    interface LoDashImplicitObjectWrapper<T> {
+        /**
+         * @see _.unary
+         */
+        unary(): LoDashImplicitObjectWrapper<T>;
+    }
+
+    interface LoDashExplicitObjectWrapper<T> {
+        /**
+         * @see _.unary
+         */
+        unary(): LoDashExplicitObjectWrapper<T>;
+    }
+
     //_.wrap
     interface LoDashStatic {
         /**