fix(bridge): improve missing native module error (segmentio#5)

README.md

@@ -170,3 +170,62 @@ Please note, if you are choosing to not use a dependency manager, you must keep
     ```
 
 6.  `pod install`
+
+### "Failed to load [...] native module"
+
+If you're getting a `Failed to load [...] native module` error, it means that some native code hasn't been injected to your native project.
+
+#### iOS
+
+If you're using Cocoapods, check that your `ios/Podfile` file contains the right pods :
+
+- `Failed to load Analytics native module`, look for the core native module:
+  ```ruby
+  pod 'RNAnalytics', :path => '../node_modules/@segment/analytics-react-native'
+  ```
+- `Failed to load [...] integration native module`, look for the integration native module, example with Google Analytics:
+  ```ruby
+  pod 'RNAnalyticsIntegration-Google-Analytics', :path => '../node_modules/@segment/analytics-react-native-google-analytics'
+  ```
+
+Also check that your `Podfile` is synchronized with your workspace, run `pod install` in your `ios` folder.
+
+If you're not using Cocoapods please check that you followed the [iOS support without CocoaPods](#ios-support-without-cocoapods) instructions carefully.
+
+#### Android
+
+Check that `android/app/src/main/.../MainApplication.java` contains a reference to the native module:
+
+- `Failed to load Analytics native module`, look for the core native module:
+
+  ```java
+  import com.segment.analytics.reactnative.core.RNAnalyticsPackage;
+
+  // ...
+
+  @Override
+  protected List<ReactPackage> getPackages() {
+      return Arrays.<ReactPackage>asList(
+          new MainReactPackage(),
+          // ...
+          new RNAnalyticsPackage()
+      );
+  }
+  ```
+
+- `Failed to load [...] integration native module`, look for the integration native module, example with Google Analytics:
+
+  ```java
+  import com.segment.analytics.reactnative.integration.google.analytics.RNAnalyticsIntegration_Google_AnalyticsPackage;
+
+  // ...
+
+  @Override
+  protected List<ReactPackage> getPackages() {
+      return Arrays.<ReactPackage>asList(
+          new MainReactPackage(),
+          // ...
+          new RNAnalyticsIntegration_Google_AnalyticsPackage()
+      );
+  }
+  ```

package.json

@@ -68,6 +68,8 @@
     "lint-staged": "^7.2.0",
     "npm-run-all": "^4.1.3",
     "prettier": "^1.14.2",
+    "react": "16.6.0-alpha.8af6728",
+    "react-native": "^0.57.3",
     "rimraf": "^2.6.2"
   }
 }

packages/core/src/__tests__/bridge.spec.ts

@@ -0,0 +1,23 @@
+const forceRequire = (): typeof import('../bridge') => {
+	jest.resetModules()
+
+	return require.requireActual('../bridge')
+}
+
+it('should throw an error if the core native module is not linked', () => {
+	jest.setMock('react-native', {
+		NativeModules: {}
+	})
+
+	expect(forceRequire).toThrow(/Failed to load Analytics native module./)
+})
+
+it('should export the core native module', () => {
+	const RNAnalytics = {}
+
+	jest.setMock('react-native', {
+		NativeModules: { RNAnalytics }
+	})
+
+	expect(forceRequire().default).toBe(RNAnalytics)
+})

packages/core/src/bridge.ts

@@ -2,6 +2,10 @@ import { NativeModules } from 'react-native'
 
 import bridge = NativeModules.RNAnalytics
 
+if (!bridge) {
+	throw new Error('Failed to load Analytics native module.')
+}
+
 export default bridge
 export type JsonMap = NativeModules.RNAnalytics.JsonMap
 export type Bridge = typeof bridge

packages/integrations/src/gen-integrations.ts

@@ -140,6 +140,7 @@ async function prepareJs({
 		),
 		template('index.js', {
 			nativeModule,
+			name,
 			disable_ios: String(ios.disabled || false),
 			disable_android: String(android.disabled || false)
 		}),

packages/integrations/template/index.js

@@ -6,6 +6,14 @@ var disabled =
 			? '{{disable_android}}' === 'true'
 			: true
 
-module.exports = disabled
-	? { disabled: true }
-	: ReactNative.NativeModules['{{{nativeModule}}}'].setup
+if (disabled) {
+	module.exports = { disabled: true }
+} else {
+	var bridge = ReactNative.NativeModules['{{{nativeModule}}}']
+
+	if (!bridge) {
+		throw new Error('Failed to load {{{name}}} integration native module')
+	}
+
+	module.exports = bridge.setup
+}