Autolinking fails if android/app folder or Xcode project are missing

[tido64]

Environment

System:
    OS: macOS Mojave 10.14.6
    CPU: (8) x64 Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
    Memory: 938.13 MB / 16.00 GB
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 12.16.1 - /usr/local/opt/node@12/bin/node
    Yarn: 1.22.4 - /usr/local/bin/yarn
    npm: 6.13.4 - /usr/local/opt/node@12/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  SDKs:
    iOS SDK:
      Platforms: iOS 13.2, DriverKit 19.0, macOS 10.15, tvOS 13.2, watchOS 6.1
    Android SDK:
      API Levels: 26, 27, 28, 29
      Build Tools: 27.0.3, 28.0.3, 29.0.2, 29.0.3
      System Images: android-28 | Google APIs Intel x86 Atom
      Android NDK: 20.0.5594570
  IDEs:
    Android Studio: 3.5 AI-191.8026.42.35.5900203
    Xcode: 11.3.1/11C504 - /usr/bin/xcodebuild
  npmPackages:
    react: 16.9.0 => 16.9.0
    react-native: 0.61.5 => 0.61.5
  npmGlobalPackages:
    react-native-cli: 2.0.1

Description

In monorepos where packages are split by platform, react-native config is not able to populate projects because it makes assumptions on the folder structure of the package. For example, given a project like below:

my-component
└── packages
    ├── my-component-core
    │   ├── package.json
    │   └── src
    ├── my-component-android
    │   ├── build.gradle
    │   ├── package.json
    │   └── src
    └── my-component-ios
        ├── TestApp.xcworkspace
        ├── package.json
        └── src

The output of react-native config in my-component-android/-ios is currently:

{
  "..."
  "project": {
    "ios": null,
    "android": null
  }
}

This had no consequences up until 3.0, when autolinking started using it in #768. Autolinking is currently broken for repos with a different folder structure.

It is possible to work around this issue by adding a react-native.config.js with the following content:

module.exports = {
  project: {
    ios: {
      project: "ReactTestApp-Dummy.xcodeproj"
    }
  }
};

Reproducible Demo

Checkout this repo and branch: https://github.com/microsoft/react-native-test-app/tree/tido/autolink-fail-repro.

Then run the following:

cd example
yarn
pod install --project-directory=ios

Output:

% pod install --project-directory=ios

[!] Invalid `Podfile` file: undefined method `[]' for nil:NilClass.

 #  from /~/react-native-test-app/example/ios/Podfile:5
 #  -------------------------------------------
 #
 >  use_test_app! __dir__ do |target|
 #    case target
 #  -------------------------------------------

cc @arazabishov in case you need more Android details.

[tido64]

Ping @alloy, @grabbou, @thymikee

[grabbou]

Interesting, I would say that the expected and supported behaviour would be for react-native config to work within each folder, reporting either iOS or Android being present, depending on where we are.

Definitely to be fixed.

[grabbou]

Okay, this is not a bug but a feature.

The new autolinking is based on top of the legacy link, which used to look for .xcodeproj in order to work.

This requirement is no longer valid for dependencies (they can just ship with a Podfile).

For projects, .xcodeproj or .xcworkspace is still required, but I guess you're working on a prototype for detached mode, where this will be provided by the 3rd party.

Either way, leaving that as a feature.

[github-actions]

There hasn't been any activity on this issue in the past 3 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 7 days.