react-native-repackager

react-native-repackager

Adding support for custom extension's files for react-native packager

react-native-repackager is a React Native npm extension package which provide you an easy way to add files with custom extensions and to use them to override the original file while running RN packager with special parameter.

• Why do we need this package?
• Installation
• Usage
• Implementation Details
• License

why-do-we-need-this-package

One of the biggest challenges when writing tests with react environment is easy mocking. Another case, is running your app with different behavior in diffeent environments or debug\release

Consider the following use-cases:

• Under e2e tests, use localhost mock HTTP server instead of the production service endpoint
• When running ios simulator, instead of natively accessing the contacts on the device, return mock contacts
  

In order to make it's super easy to mock stuff for tests, this package approach it like we handle in JavaScript code that is different between iOS and Android. So in order to replace someFile.js, we will also create someFile.mock.js in the same directory. When the packager will run for the e2e tests, it will pick up this file instead of the original. This way, the mocks files will not find themselves in our production code.

Installation

Currently support RN 0.38 or 0.42

• Install the package from npm

npm install react-native-repackager --save

Usage

• First add your custom extension (mock) file to your project, for example:

The packager will search for custom files in the following order:

1. filename.ios.[customExtension].js \ filename.android.[customExtension].js
2. filename.[customExtension].js
3. filename.ios.js \ filename.android.js

• run react-packager with --custom-extension parameter

node node_modules/react-native/local-cli/cli.js start --customExtensions=foo

• for more then one file extension type

node node_modules/react-native/local-cli/cli.js start --customExtensions='foo, bar'

Limitation - Currently support only react native packager in debug mode (will not replace file for Release version)

Implementation Details

• This package inject code into the RN packager implementation (!)

• The repository contain only one patch file, and postinstall script. After npm install the package will replace the relevant files in RN packager to make the magic.

License

MIT