Make fp versions of set and setWith immutable.

lib/fp/base.js

@@ -22,6 +22,7 @@ function baseConvert(util, name, func) {
 
   var _ = isLib ? func : {
     'ary': util.ary,
+    'cloneDeep': util.cloneDeep,
     'curry': util.curry,
     'forEach': util.forEach,
     'isFunction': util.isFunction,
@@ -31,6 +32,7 @@ function baseConvert(util, name, func) {
   };
 
   var ary = _.ary,
+      cloneDeep = _.cloneDeep,
       curry = _.curry,
       each = _.forEach,
       isFunction = _.isFunction,
@@ -90,6 +92,21 @@ function baseConvert(util, name, func) {
     };
   };
 
+  var immutSetWrap = function(func) {
+    return function() {
+      var index = -1,
+          length = arguments.length,
+          args = Array(length);
+
+      while (++index < length) {
+        args[index] = arguments[index];
+      }
+      args[0] = cloneDeep(args[0]);
+      func.apply(undefined, args);
+      return args[0];
+    };
+  };
+
   var iterateeAry = function(func, n) {
     return function() {
       var length = arguments.length,
@@ -160,6 +177,9 @@ function baseConvert(util, name, func) {
     else if (mutateMap.object[name]) {
       func = immutObjectWrap(func);
     }
+    else if (mutateMap.set[name]) {
+      func = immutSetWrap(func);
+    }
     var result;
     each(mapping.caps, function(cap) {
       each(mapping.aryMethodMap[cap], function(otherName) {

lib/fp/mapping.js

@@ -85,15 +85,15 @@ module.exports = {
       'invokeMap,isMatch,lastIndexOf,map,mapKeys,mapValues,matchesProperty,maxBy,' +
       'mean,minBy,merge,omit,overArgs,pad,padLeft,padRight,parseInt,partition,' +
       'pick,pull,pullAll,pullAt,random,range,rangeRight,rearg,reject,remove,repeat,' +
-      'result,sampleSize,set,some,sortBy,sortByOrder,sortedIndexBy,sortedLastIndexBy,' +
+      'result,sampleSize,some,sortBy,sortByOrder,sortedIndexBy,sortedLastIndexBy,' +
       'sortedUniqBy,startsWith,subtract,sumBy,take,takeRight,takeRightWhile,takeWhile,' +
       'throttle,times,truncate,union,uniqBy,without,wrap,xor,zip,zipObject').split(','),
     3: (
       'assignWith,clamp,differenceBy,extendWith,getOr,inRange,intersectionBy,' +
       'isEqualWith,isMatchWith,mergeWith,omitBy,pickBy,pullAllBy,reduce,' +
-      'reduceRight,slice,transform,unionBy,xorBy,zipWith').split(','),
+      'reduceRight,set,slice,transform,unionBy,xorBy,zipWith').split(','),
     4:
-      ['fill']
+      ['fill', 'setWith']
   },
 
   /** Used to map ary to rearg configs by method ary. */
@@ -108,6 +108,7 @@ module.exports = {
     'clamp': [2, 0, 1],
     'reduce': [2, 0, 1],
     'reduceRight': [2, 0, 1],
+    'setWith': [3, 2, 1, 0],
     'slice': [2, 0, 1],
     'transform': [2, 0, 1]
   },
@@ -142,6 +143,10 @@ module.exports = {
       'extendWith': true,
       'merge': true,
       'mergeWith': true
+    },
+    'set': {
+      'set': true,
+      'setWith': true
     }
   },
 

lib/fp/util.js

@@ -1,5 +1,6 @@
 module.exports = {
   'ary': require('lodash/function/ary'),
+  'cloneDeep': require('lodash/lang/cloneDeep'),
   'curry': require('lodash/function/curry'),
   'forEach': require('lodash/internal/arrayEach'),
   'isFunction': require('lodash/lang/isFunction'),

test/test-fp.js

@@ -651,10 +651,11 @@
 
   (function() {
     var array = [1, 2, 3],
-        object = { 'a': 1 };
+        object = { 'a': 1 },
+        deepObject = { 'a': { 'b': 2, 'c': 3 } };
 
     QUnit.test('should not mutate values', function(assert) {
-      assert.expect(28);
+      assert.expect(32);
 
       function Foo() {}
       Foo.prototype = { 'b': 2 };
@@ -753,6 +754,18 @@
 
       assert.deepEqual(value, array, 'fp.reverse');
       assert.deepEqual(actual, [3, 2, 1], 'fp.reverse');
+
+      value = _.cloneDeep(deepObject);
+      actual = fp.set(3, 'a.b', value);
+
+      assert.deepEqual(value, deepObject, 'fp.set');
+      assert.deepEqual(actual, { 'a': { 'b': 3, 'c': 3 } }, 'fp.set');
+
+      value = _.cloneDeep(deepObject);
+      actual = fp.setWith(Object, 4, 'd.e', value);
+
+      assert.deepEqual(value, deepObject, 'fp.setWith');
+      assert.deepEqual(actual, { 'a': { 'b': 2, 'c': 3 }, 'd': { 'e': 4 } }, 'fp.setWith');
     });
   }());