jest test suite - work start

.babelrc

@@ -0,0 +1,3 @@
+{
+    "presets": ["react-native"]
+}  

__mocks__/RNBackgroundDownload.js

@@ -0,0 +1,6 @@
+import { NativeModules } from 'react-native';
+
+NativeModules.RNBackgroundDownload = {
+    download: jest.fn(),
+    addListener: jest.fn()
+};

__tests__/mainTest.js

@@ -0,0 +1,10 @@
+import RNBackgroundDownload from '../index';
+import DownloadTask from '../lib/downloadTask';
+
+test('download should return a downloadTask', () => {
+    expect(RNBackgroundDownload.download({
+        id: 'test',
+        url: 'test',
+        destination: 'test'
+    })).toBeInstanceOf(DownloadTask);
+});

package.json

@@ -1,11 +1,10 @@
-
 {
   "name": "react-native-background-download",
   "version": "1.0.0",
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest"
   },
   "keywords": [
     "react-native"
@@ -14,5 +13,13 @@
   "license": "",
   "peerDependencies": {
     "react-native": "^0.41.2"
+  },
+  "devDependencies": {
+    "jest": "^23.1.0",
+    "react-native": "^0.55.4"
+  },
+  "jest": {
+    "preset": "react-native",
+    "setupFiles": ["./__mocks__/RNBackgroundDownload.js"]
   }
 }