Extract util functions

Author: mattphillips

src/index.js

@@ -1,5 +1,4 @@
-const isObject = o => o != null && typeof o === 'object';
-const isEmpty = o => Object.keys(o).length === 0;
+import { isEmpty, isObject } from './utils';
 
 const diff = (lhs, rhs) => {
   if (lhs === rhs) return {}; // equal return no diff

src/utils/index.js

@@ -0,0 +1,2 @@
+export const isObject = o => o != null && typeof o === 'object';
+export const isEmpty = o => Object.keys(o).length === 0;

src/utils/index.spec.js

@@ -0,0 +1,50 @@
+import { expect } from 'chai';
+import forEach from 'mocha-each';
+
+import { isEmpty, isObject } from './';
+
+describe('utils', () => {
+
+  describe('.isEmpty', () => {
+    describe('returns true', () => {
+      it('when given an empty object', () => {
+        expect(isEmpty({})).to.be.true;
+      });
+
+      it('when given an empty array', () => {
+        expect(isEmpty([])).to.be.true;
+      });
+    });
+
+    describe('returns false', () => {
+      it('when given an empty object', () => {
+        expect(isEmpty({ a: 1 })).to.be.false;
+      });
+
+      it('when given an empty array', () => {
+        expect(isEmpty([1])).to.be.false;
+      });
+    });
+  });
+
+  describe('.isObject', () => {
+    it('returns true when value is an object', () => {
+      expect(isObject({})).to.be.true;
+    });
+
+    it('returns true when value is an array', () => {
+      expect(isObject([])).to.be.true;
+    });
+
+    forEach([
+      ['int', 1],
+      ['string', 'a'],
+      ['boolean', true],
+      ['null', null],
+      ['undefined', undefined],
+      ['function', () => ({})],
+    ]).it('returns false when value is of type: %s', (type, value) => {
+      expect(isObject(value)).to.be.false;
+    });
+  });
+});