react-native-contains-native-code

A small module to test whether a given react-native dependency contains native or JS-only code.

• Checks if the dependency contains an xcode or gradle project ✓
• Checks if the dependency contains RNPM hooks ✓
• CLI ✓
• API ✓

ToC

• Why
• Usage
  • CLI
  • API
• How does it work?
• An example integration

Why

This utility was built in order to support "web-like release agility" for react-native projects.

This means, in detail, that paired with a tool like Microsoft code-push and a little bit of extra scripting, deployments can be made continuously and be released either as JS-only changes via code-push or with native changes through the iOS App Store / Google Play Store.

Usage

CLI

The binary can be used with either absolute or paths:

$ contains-native-code /home/myname/work/myproject/node_modules/a-react-native-dependency

or with the name of a dependency:

$ contains-native-code another-react-native-dependency

In the latter case it will look in the same node_modules folder where it has been installed for a dependeny with the given name.

The binary itself will be installed to node_modules/.bin and is available on the npm path.

API

This package exports a single function that can be called with a path to the dependency in question:

var containsNativeCode = require('react-native-contains-native-code');
console.log(containsNativeCode('/path/to/a/react-native-dependency'));

Or, with ES6 syntax:

import containsNativeCode from 'react-native-contains-native-code';
console.log(containsNativeCode('/path/to/a/react-native-dependency'));

How does it work?

The script reads the package.json manifest of the given dependency and checks:

• whether the key rnpm is present
• wheter the given dependency contains a *.xcodeproj file
• whether the given dependency contains an android/build.gradle or android/app/build.gradle file

This is a similar behaviour to how react-native link works internally.

An example integration

In order to use this script in a automated release process the deployment script needs to do the following tasks:

1. check if commits have been made inside the projects android/ or ios/ folder
2. create a list of added/removed/changed dependencies from the package.json
3. run this script for every dependency that has been found through step 1
   • if it turns out that no native changes were made between the last version and current HEAD do a code-push release
   • otherwise build the native code and push to the app/play store

To be able to execute these steps the source code of the application needs to be versioned via a version control system (for example git).

It is recommended to not directly push to production but to employ a "staging" environment and use manual or automated integration tests to verify the release because this method might not be bullet proof.