Update an APK file with a new React Native JS bundle

refresh_apk_js_bundle.rb

module Fastlane
  module Actions
    module SharedValues
      REFRESH_APK_JS_BUNDLE_CUSTOM_VALUE = :REFRESH_APK_JS_BUNDLE_CUSTOM_VALUE
    end

    class RefreshApkJsBundleAction < Action
      def self.run(params)
        # fastlane will take care of reading in the parameter and fetching the environment variable:
        require 'fastlane/actions/gradle'
        sh('bash ./fastlane/install-tools-android.sh')

        unzipped_path = "./mobile_app"
        js_bundle_path = "#{unzipped_path}/assets/index.android.bundle"
        
        sh("mv ./android/app/build/outputs/apk/release/mobile_app.apk ./mobile_app.apk")
        sh("rm -rf ./android/app/build/outputs/apk/release/mobile_app.apk")

        sh("apktool d mobile_app.apk")
        sh("rm -rf mobile_app.apk")
        sh("rm -rf #{js_bundle_path}")
       
        UI.message("Creating a new unminified JS bundle")
        sh("yarn react-native bundle \
          --dev false \
          --minify false \
          --platform android \
          --entry-file index.js \
          --reset-cache \
          --bundle-output index.android.bundle \
          --sourcemap-output index.android.bundle.map")

        UI.message("Compiling JS bundle to Hermes bytecode")
        sh("node_modules/react-native/sdks/hermesc/linux64-bin/hermesc \
          -O -emit-binary \
          -output-source-map \
          -out=index.android.bundle.hbc \
          index.android.bundle")
        sh("rm -f index.android.bundle")
        sh("mv index.android.bundle.hbc index.android.bundle")
        
        UI.message("Copying JS bundle to APK assets")
        sh("cp index.android.bundle #{js_bundle_path}")
        
        # Upload the new source maps to a crash reporting tool.
        #other_action.sentry_upload_sourcemaps(
        #  bundle_name: "index.android.bundle",
        #  release: "mobile-app@#{ENV["APP_VERSION"]}+#{params[:build_number]}",
        #)
        
        UI.message("Setting app version and build number")
        UI.message("App version: #{ENV["APP_VERSION"]}")
        UI.message("Build number: #{params[:build_number]}")
        sh("cd #{unzipped_path} && yq -i '.versionInfo.versionName = \"#{ENV["APP_VERSION"]}\"' apktool.yml")
        sh("cd #{unzipped_path} && yq -i '.versionInfo.versionCode = #{params[:build_number]}' apktool.yml")
        
        UI.message("Zipping APK")
        sh("apktool b #{unzipped_path} -o mobile_app.apk")

        UI.message("Resigning APK")
        # TODO: Update to zipalign -P 16 when upgrading to a newer React Native 
        # https://github.com/facebook/react-native/issues/45054
        sh("zipalign -P 4 -f -v 4 ./mobile_app.apk ./mobile_app-aligned.apk")
        sh("rm -rf ./mobile_app.apk")
        sh("mv './mobile_app-aligned.apk' './mobile_app.apk'")

        # Make sure to use the same signing configuration as the one used in the build.gradle
        sh("apksigner sign -v --v2-signing-enabled true --ks ./android/app/release.keystore --ks-key-alias #{ENV['ANDROID_KEYSTORE_ALIAS']} --ks-pass pass:'#{ENV['ANDROID_KEYSTORE_PRIVATE_KEY_PASSWORD']}' --key-pass pass:'#{ENV['ANDROID_KEYSTORE_PASSWORD']}' mobile_app.apk")
        
        # Copy  APK to the android build folder so it can cached by the CI at the end of the build
        sh("cp ./mobile_app.apk ./android/app/build/outputs/apk/release/mobile_app.apk")

      end

      #####################################################
      # @!group Documentation
      #####################################################

      def self.description
        'A short description with <= 80 characters of what this action does'
      end

      def self.details
        # Optional:
        # this is your chance to provide a more detailed description of this action
        'You can use this action to do cool things...'
      end

      def self.available_options
        # Define all options your action supports.

        # Below a few examples
        [
          FastlaneCore::ConfigItem.new(key: :build_number,
                                       # The name of the environment variable
                                       env_name: 'FL_REFRESH_APK_JS_BUNDLE_BUILD_NUMBER',
                                       # a short description of this parameter
                                       description: 'Build number for the new APK',
                                       verify_block: proc do |value|
                                         unless value && !value.empty?
                                           UI.user_error!("No build number for RefreshIpaJsBundleAction given, pass using `build_number: '231'`")
                                         end
                                         # UI.user_error!("Couldn't find file at path '#{value}'") unless File.exist?(value)
                                       end),
        ]
      end

      def self.output
        # Define the shared values you are going to provide
        # Example
        [
          ['REFRESH_APK_JS_BUNDLE_CUSTOM_VALUE', 'A description of what this value contains']
        ]
      end

      def self.return_value
        # If your method provides a return value, you can describe here what it does
      end

      def self.authors
        # So no one will ever forget your contribution to fastlane :) You are awesome btw!
        ['https://github.com/cristiangu']
      end

      def self.is_supported?(platform)
        platform == :android
      end
    end
  end
end