Unit tests for deepMerge

test/specs/utils/deepMerge.spec.js

+var deepMerge = require('../../../lib/utils').deepMerge;
+
+describe('utils::deepMerge', function () {
+  it('should be immutable', function () {
+    var a = {};
+    var b = {foo: 123};
+    var c = {bar: 456};
+
+    deepMerge(a, b, c);
+
+    expect(typeof a.foo).toEqual('undefined');
+    expect(typeof a.bar).toEqual('undefined');
+    expect(typeof b.bar).toEqual('undefined');
+    expect(typeof c.foo).toEqual('undefined');
+  });
+
+  it('should deepMerge properties', function () {
+    var a = {foo: 123};
+    var b = {bar: 456};
+    var c = {foo: 789};
+    var d = deepMerge(a, b, c);
+
+    expect(d.foo).toEqual(789);
+    expect(d.bar).toEqual(456);
+  });
+
+  it('should deepMerge recursively', function () {
+    var a = {foo: {bar: 123}};
+    var b = {foo: {baz: 456}, bar: {qux: 789}};
+
+    expect(deepMerge(a, b)).toEqual({
+      foo: {
+        bar: 123,
+        baz: 456
+      },
+      bar: {
+        qux: 789
+      }
+    });
+  });
+
+  it('should remove all references from nested objects', function () {
+    var a = {foo: {bar: 123}};
+    var b = {};
+    var d = deepMerge(a, b);
+
+    expect(d).toEqual({
+      foo: {
+        bar: 123
+      }
+    });
+
+    expect(d.foo).not.toBe(a.foo);
+  });
+
+  it('handles null and undefined arguments', function () {
+    expect(deepMerge(undefined, undefined)).toEqual({});
+    expect(deepMerge(undefined, {foo: 123})).toEqual({foo: 123});
+    expect(deepMerge({foo: 123}, undefined)).toEqual({foo: 123});
+
+    expect(deepMerge(null, null)).toEqual({});
+    expect(deepMerge(null, {foo: 123})).toEqual({foo: 123});
+    expect(deepMerge({foo: 123}, null)).toEqual({foo: 123});
+  });
+});
+