react-native-launch-arguments

React Native module to get launch arguments.

Makes passing parameters from testing libraries and debugs tools to react-native super easy.

Install

npm i react-native-launch-arguments
cd ios && pod install && cd ..

Usage

In you code

Javascript

import { LaunchArguments } from "react-native-launch-arguments";
LaunchArguments.value();

Typescript

import { LaunchArguments } from "react-native-launch-arguments";
interface MyExpectedArgs {
  authToken?: string;
  skipAuth?: boolean;
}
LaunchArguments.value<MyExpectedArgs>();

Integrating with End-to-end testing tools and debuggers

The intended use is with end-to-end tools like Detox.

Detox

• See device.launchApp({launchArgs:{...}})
• See launch arguments guide for full details.

Appium

• optionalIntentArguments (Android) and processArguments (iOS)

  capabilities: {
    optionalIntentArguments: `--ez myBool true --es myStr 'string text'`, // Android
    processArguments: {args : ['-myBool', 'true','-myStr', 'string text']}, // iOS
  }

Maestro

• arguments parameter of launchApp command

  - launchApp:
      appId: "com.example.app"
      arguments:
         foo: "This is a string"
         isFooEnabled: false
         fooValue: 3.24
         fooInt: 3

XCode

• XCode Launch Args
• In XCode add launch arguments on the "Arguments" tab in the "Run" section of the Scheme editor:
  • Product -> Scheme -> Edit Scheme... -> Run -> Arguments tab -> Arguments Passed On Launch
  • Set each arg witha preceding -.
  • For example if you want to set arg hello to "world" to receive a LaunchArgs instance of{ "hello":"world" }, you would enter the following into the entry space for the arg:

  -hello "world"

Platform-specific Notes

iOS

It takes data from [[NSProcessInfo processInfo] arguments]

Verifying install on iPhone simulator

You can use xcrun to boot your app on the simulator.

The following command-line will load your app on the booted iOS simulator. Just replace com.MyAppBundleId with your Bundle Identifier, and the params with your params.

xcrun simctl launch booted com.MyAppBundleId -noParams -param "hello"

Android

It takes data from currentActivity.getIntent().getBundleExtra("launchArgs") for detox and intent.getExtras() for ADB params

Caveats on Android

React-Native

Due to React Native issue #37518, on Android, the module force-waits for the Android activity to reach the RESUMED state, before moving foward with native-modules initialization completion. While commonly the wait is scarce (the activity is already in the resumed state at this point), until the RN issue is fixed, the module may introduce delays in app loading time in some edge cases.

Expo

There is know expo bug with empty passed arguments.