Simple Fastlane setup for React-Native (Android - iOS)

Appfile

# iOS
app_identifier "com.myapp.app" # The bundle identifier of your app
apple_id "[email protected]" # Your Apple email address
team_id "1234ABCD"  # Developer Portal Team ID

# Android
json_key_file "./google-play-api-secret.json" # Path to the json secret file - Follow https://github.com/fastlane/supply#setup to get one
package_name "com.myapp.app" # Your Android app package

Deliverfile

# iOS
app_identifier "com.myapp.app" # The bundle identifier of your app
username "[email protected]" # Your Apple ID user

Fastfile

fastlane_version "1.86.1"

default_platform :ios

platform :ios do
  before_all do
    ENV["SLACK_URL"] = "https://hooks.slack.com/services/..."
  end

  desc "Submit a new Build to Apple TestFlight"
  desc "This will also make sure the profile is up to date"
  lane :alpha do
    sigh
    increment_build_number(xcodeproj: './ios/MyApp.xcodeproj') # Increment the build number
    gym(scheme: "MyApp", project: './ios/MyApp.xcodeproj') # Build the app
    pilot(skip_submission: true) # Upload the app to TestFlight
  end

  after_all do |lane|
    slack(channel: "deploys", message: "Successfully deployed new MyApp alpha update to TestFlight.")
  end
end

platform :android do
  before_all do
    ENV["SLACK_URL"] = "https://hooks.slack.com/services/..."
  end

  desc "Submit a new Alpha Build to Play Store"
  lane :alpha do
    gradle(task: 'clean', project_dir: "android/") # Clean the Gradle project
    gradle(task: "assemble", build_type: "Release", project_dir: "android/") # Build the Release APK
    supply(track: "alpha", apk: "android/app/build/outputs/apk/app-release.apk") # Upload the APK to the Play Store (alpha)
  end

  after_all do |lane|
    slack(channel: "deploys", message: "Successfully deployed new MyApp alpha update to the Play Store.")
  end
end

good stuff. thank you!

@mmazzarolo so my app-release.apk is app-release-unisigned.apk, are these notably different or should I just change the file path to android/app/build/outputs/apk/app-release-unsigned.apk?

@danstepanov is a not signed version of your app and will not be approved to be installed on devices by playstore.
To upload an acceptable version of your app you need to sign the app.