Set up Jest to be able to test RN UI components (#96)

.gitignore

@@ -17,3 +17,6 @@ yarn-error.log
 
 # Exponent
 .exponent
+
+# Jest
+coverage

jest-setup.js

@@ -0,0 +1,21 @@
+/* @flow */
+
+// See https://github.com/facebook/jest/issues/2208
+jest.mock('Linking', () => {
+  return {
+    addEventListener: jest.fn(),
+    removeEventListener: jest.fn(),
+    openURL: jest.fn(),
+    canOpenURL: jest.fn(),
+    getInitialURL: jest.fn().mockImplementation((value: string) => Promise.resolve(value)),
+  }
+});
+
+// See https://github.com/facebook/react-native/issues/11659
+jest.mock('ScrollView', () => {
+  const RealComponent = require.requireActual('ScrollView');
+  class ScrollView extends RealComponent {
+    scrollTo = () => {}
+  }
+  return ScrollView
+});

package.json

@@ -26,7 +26,7 @@
     "start": "node ./node_modules/react-native/local-cli/cli.js start --config ./rn-cli.config.js",
     "run-playground-ios": "cd examples/NavigationPlayground && react-native run-ios",
     "run-playground-android": "cd examples/NavigationPlayground && react-native run-android",
-    "test": "BABEL_ENV=development jest",
+    "test": "jest",
     "flow": "flow",
     "prepublish": "npm run clean && npm run build"
   },
@@ -55,7 +55,8 @@
     "jest": "^18.1.0",
     "react": "~15.4.0",
     "react-native": "^0.40.0",
-    "react-native-vector-icons": "^3.0.0"
+    "react-native-vector-icons": "^3.0.0",
+    "react-test-renderer": "^15.4.2"
   },
   "peerDependencies": {
     "react": "*",
@@ -69,9 +70,14 @@
     "react-native-tab-view": "^0.0.54"
   },
   "jest": {
-    "testPathDirs": [
-      "src/"
+    "notify": true,
+    "preset": "react-native",
+    "testRegex": "./src/.*\\-test\\.js$",
+    "setupFiles": [
+      "<rootDir>/jest-setup.js"
     ],
-    "notify": true
+    "modulePathIgnorePatterns": [
+      "examples"
+    ]
   }
 }

yarn.lock

@@ -3904,6 +3904,13 @@ react-proxy@^1.1.7:
     lodash "^4.6.1"
     react-deep-force-update "^1.0.0"
 
+react-test-renderer@^15.4.2:
+  version "15.4.2"
+  resolved "https://registry.yarnpkg.com/react-test-renderer/-/react-test-renderer-15.4.2.tgz#27e1dff5d26d0e830f99614c487622bc831416f3"
+  dependencies:
+    fbjs "^0.8.4"
+    object-assign "^4.1.0"
+
 react-timer-mixin@^0.13.2:
   version "0.13.3"
   resolved "https://modules.verse.link/react-timer-mixin/-/react-timer-mixin-0.13.3.tgz#0da8b9f807ec07dc3e854d082c737c65605b3d22"