Network requests silently fail in Android since v0.63.0

Description

None of the network examples work in Android since v0.63.0; iOS is unaffected. Confirmed this is still an issue in v0.63.1 and v0.63.2 (the latest as of this report). Failures are silent and simply result in no data being returned to the view.

Since this is an issue with the network APIs, this affects all libraries that rely on those APIs, e.g., Apollo.

React Native version:

System:
    OS: macOS 10.15.6
    CPU: (6) x64 Intel(R) Core(TM) i5-8500B CPU @ 3.00GHz
    Memory: 960.03 MB / 32.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 12.18.2 - /var/folders/tb/wx5d6rj53qjdg6sr4bmb1l840000gn/T/yarn--1597082804831-0.5290956210609348/node
    Yarn: 1.22.4 - /var/folders/tb/wx5d6rj53qjdg6sr4bmb1l840000gn/T/yarn--1597082804831-0.5290956210609348/yarn
    npm: 6.14.5 - ~/.nvm/versions/node/v12.18.2/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.9.3 - /usr/local/bin/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 13.6, DriverKit 19.0, macOS 10.15, tvOS 13.4, watchOS 6.2
    Android SDK: Not Found
  IDEs:
    Android Studio: 4.0 AI-193.6911.18.40.6626763
    Xcode: 11.6/11E708 - /usr/bin/xcodebuild
  Languages:
    Java: 11.0.8 - /usr/bin/javac
    Python: 2.7.16 - /usr/bin/python
  npmPackages:
    @react-native-community/cli: Not Found
    react: 16.13.1 => 16.13.1 
    react-native: 0.63.2 => 0.63.2 
  npmGlobalPackages:
    *react-native*: Not Found

Steps To Reproduce

1. Install the last known good version:
2. npx react-native init AwesomeProject --version 0.62.2
3. Replace the contents of App.js with one of the examples from the network docs, e.g., the Fetch Example.
4. Run the application in iOS.
5. npx react-native run-ios
6. Note that the fetch example displays as intended.
7. Run the application in Android.
8. npx react-native run-android
9. Note that the fetch example displays as intended.
10. Install latest (v0.63.2 as of this report):
11. npx react-native init AwesomeProject
12. Replace the contents of App.js with one of the examples from the network docs, e.g., the Fetch Example.
13. Run the application in iOS.
14. npx react-native run-ios
15. Note that the fetch example displays as intended.
16. Run the application in Android.
17. npx react-native run-android
18. Note that a blank screen is rendered.

Expected Results

The results should be rendered as they are on iOS and as they are on versions prior to v0.63.0. At the very least, would expect to see the activity indicator and possibly an error indicating the request failed.

Snack, code example, screenshot, or link to a repository:

https://snack.expo.io/2HgnLjyI_

[scobo]

More info: If we invoke Metro via yarn in our monorepo, it seems to “poison” the Metro cache. Running yarn react-native --reset-cache in the monorepo has no effect. We have to create a demo app with the same package name to clean it, e.g., npx react-native init <ourproject> && cd <ourproject> && npx react-native start --reset-cache, then the app works again. It appears Metro caches based on the project name, is that accurate?

Also, while this workaround works for the development builds, the release builds still have no network connectivity, e.g., npx react-native run-android works but not npx react-native run-android --variant=release.

Edit: Running a release build also appears to “poison” the Metro cache.

[danmaas]

@cristianoccazinsp Here is a Gist with the relevant code excerpt:

https://gist.github.com/danmaas/c60af5fed9f55d2bc616ce302696540d

This overrides the default OkHTTP client factory with a shim that intercepts DNS resolutions and sorts the result list to return IPv4 addresses before IPv6 addresses.