Reduce for objects

src/seamless-immutable.js

@@ -577,6 +577,15 @@ function immutableInit(config) {
     return result;
   }
 
+  function objectReduce(callback, initialValue) {
+    var keys = Object.keys(this);
+    var self = this;
+    var values = keys.map(function(key) { return self[key] });
+    return values.reduce(function(accumulator, currentValue, index) {
+      return callback(accumulator, currentValue, keys[index], index, this)
+    }, initialValue);
+  }
+
   // Creates plain object to be used for cloning
   function instantiatePlainObject() {
     return {};
@@ -586,6 +595,7 @@ function immutableInit(config) {
   function makeImmutableObject(obj) {
     if (!globalConfig.use_static) {
       addPropertyTo(obj, "merge", merge);
+      addPropertyTo(obj, "reduce", objectReduce);
       addPropertyTo(obj, "replace", objectReplace);
       addPropertyTo(obj, "without", without);
       addPropertyTo(obj, "asMutable", asMutableObject);
@@ -723,6 +733,7 @@ function immutableInit(config) {
   Immutable.getIn          = toStatic(getIn);
   Immutable.flatMap        = toStatic(flatMap);
   Immutable.asObject       = toStatic(asObject);
+  Immutable.reduce         = toStaticObjectOrArray(objectReduce, Array.prototype.reduce);
   if (!globalConfig.use_static) {
       Immutable.static = immutableInit({
           use_static: true

test/ImmutableObject.spec.js

@@ -1,11 +1,12 @@
 var testMerge     = require("./ImmutableObject/test-merge.js");
-var testReplace     = require("./ImmutableObject/test-replace.js");
+var testReplace   = require("./ImmutableObject/test-replace.js");
 var testCompat    = require("./ImmutableObject/test-compat.js");
 var testWithout   = require("./ImmutableObject/test-without.js");
 var testAsMutable = require("./ImmutableObject/test-asMutable.js");
 var testSet       = require("./ImmutableObject/test-set.js");
 var testUpdate    = require("./ImmutableObject/test-update.js");
-var testGetIn    = require("./ImmutableObject/test-getIn.js");
+var testGetIn     = require("./ImmutableObject/test-getIn.js");
+var testReduce    = require("./ImmutableObject/test-reduce");
 var devBuild      = require("../seamless-immutable.development.js");
 var prodBuild     = require("../seamless-immutable.production.min.js");
 var getTestUtils  = require("./TestUtils.js");
@@ -27,6 +28,7 @@ var getTestUtils  = require("./TestUtils.js");
       testSet(config);
       testUpdate(config);
       testGetIn(config);
+      testReduce(config)
     });
   });
 });

test/ImmutableObject/test-reduce.js

@@ -0,0 +1,73 @@
+var JSC          = require("jscheck");
+var assert       = require("chai").assert;
+var _            = require("lodash");
+var getTestUtils = require("../TestUtils.js");
+
+
+module.exports = function(config) {
+  var Immutable = config.implementation;
+  var TestUtils = getTestUtils(Immutable);
+
+  describe("#reduce", function() {
+    it("static reduces object to array", function () {
+        var ob = {
+          key1: 'value1',
+          key2: {
+            key3: 'value3'
+          }
+        };
+        var expected = Immutable([
+          ['key1', 'value1'],
+          ['key2', { key3: 'value3' }],
+        ]);
+        var immutable = Immutable(ob);
+
+        TestUtils.assertJsonEqual(
+          Immutable.reduce(immutable, function(accumulator, currentValue, key, index, object) {
+            return accumulator.concat([[key, currentValue]]);
+          }, Immutable([])),
+          expected
+        );
+    });
+
+    it("non-static reduces object to array", function () {
+        var ob = {
+          key1: 'value1',
+          key2: {
+            key3: 'value3'
+          }
+        };
+        var expected = Immutable([
+          ['key1', 'value1'],
+          ['key2', { key3: 'value3' }],
+        ]);
+        var immutable = Immutable(ob);
+
+        TestUtils.assertJsonEqual(
+          immutable.reduce(function(accumulator, currentValue, key, index, object) {
+            return accumulator.concat([[key, currentValue]]);
+          }, Immutable([])),
+          expected
+        );
+    });
+    it("static reduces non-immutable object", function () {
+        var ob = {
+          key1: 'value1',
+          key2: {
+            key3: 'value3'
+          }
+        };
+        var expected = [
+          ['key1', 'value1'],
+          ['key2', { key3: 'value3' }],
+        ];
+
+        TestUtils.assertJsonEqual(
+          Immutable.reduce(ob, function(accumulator, currentValue, key, index, object) {
+            return accumulator.concat([[key, currentValue]]);
+          }, Immutable([])),
+          expected
+        );
+    });
+  })
+}