Use Gemini to translate flutter .arb files to multiple languages

integration_test.dart

import 'dart:io';
import 'package:integration_test/integration_test_driver_extended.dart';

Future<void> main() async {
  try {
    await integrationDriver(
      onScreenshot: (screenshotName, screenshotBytes, [args]) async {
        final File image = await File('play/assets/screenshots/$screenshotName.png').create(recursive: true);
        image.writeAsBytesSync(screenshotBytes);
        return true;
      },
    );
  } catch (e) {
    print('Error occured: $e');
  }
}

make_arb_files.csv

make_arb_files.sh

#!/bin/bash

# Use Gemini to translate flutter .arb files to multiple languages.

gemini_key=$(cat gemini_key)
arb=$(cat "lib/l10n/app_en.arb")

while IFS=',' read -r col1 col2 col3 rest_of_line; do
	language="${col1//\"/}"
	locale="${col2//\"/}"
	locale_prefix="${col3//\"/}"

  output_file="lib/l10n/app_${locale_prefix}.arb"

  if [ ! -e "$output_file" ]; then

    if [[ "$locale" != "en" ]]; then

      echo "Language: $language Language code: $locale"

      # main prompt
      request="I am the author of an Android app titled 'Simplest Percentage Calculator'."
      request="$request The app does Foo, Bar and Baz things for the user. " # TODO provide a short description of the app here to give context
      request="$request I need you to translate the application strings from English to $language."
      request="$request Please translate the following .arb file to $language ($locale locale)."
      request="$request Only output the JSON data without any other text."
      request="$request Preserve the keys and only translate the values."
      request="$request Preserve the substrings in square brackets or curly brackets, i.e. do not translate the [foo] parts or the {bar} parts."

      # append english arb file
      request="$request $arb"

      # escape json for embedding into json
      request=$(echo "$request" | jq -Rsa .)


      # embed json into json
      request="{\"contents\": [{\"parts\":[{\"text\": $request}]}],\"generationConfig\": { \"response_mime_type\": \"application/json\" }}"

      echo "$request"  | jq .

      response=$(curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash:generateContent?key=${gemini_key}" \
        -H 'Content-Type: application/json' \
        -X POST \
        -d "$request")

      # remove gemini metadata
      response=$(echo "$response" | jq .candidates[0].content.parts[0].text )

      # remove prefix
      response="${response#\"\`\`\`json\\n}"

      #remove suffix
      response=${response%\\n\`\`\`\\n\"}

      # unescape
      response=$(echo "$response" | sed 's/^"//; s/\\n//g; s/"$//; s/\\"/"/g' | jq .)

      # write translation file or show error
      if echo "$response" | jq . ; then
        echo "$response" >"$output_file"
      else
        echo "Error: Could not write $language translation to $output_file"
      fi
    fi
  fi
done < "make_arb_files.csv"

# The Punjabi language has two scripts, the Shahmukhi and the Gurmukhi alphabet.
# Here we set a default to be used if the device's locale is not specific.
cp lib/l10n/app_pa-PK.arb lib/l10n/app_pa.arb

make_screenshots.sh

#!/bin/bash

for arb in lib/l10n/*.arb; do
	 noext=${arb%.arb}
	 locale=${noext#lib/l10n/app_}
	 if test -f play/assets/screenshots/screenshot-$locale-1.png; then
		continue
	fi
	flutter drive --driver=test_driver/integration_test.dart --target=test/screenshots_test.dart --dart-define=TEST_LOCALE=$locale
done

screenshots_test.dart

import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';
import 'package:flutter_gen/gen_l10n/app_localizations.dart';

// TODO import your app here

takeScreenShot(
    {required IntegrationTestWidgetsFlutterBinding binding,
    required WidgetTester tester,
    required String screenShotName}) async {
  if (kIsWeb) {
    await binding.takeScreenshot(screenShotName);
    return;
  } else if (Platform.isAndroid) {
    await binding.convertFlutterSurfaceToImage();
    await tester.pumpAndSettle();
  }
  await binding.takeScreenshot(screenShotName);
}

void main() {
  final binding = IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  String localeStr =
  const String.fromEnvironment('TEST_LOCALE', defaultValue: 'en_US');
  var parts = localeStr.split('_');
  Locale locale;
  if (parts.length == 2) {
    locale = Locale(parts.first,parts.last);
  } else {
    locale = Locale(parts.first);
  }

  testWidgets('take screenshot 1', (WidgetTester tester) async {
    // Load app widget.
    await tester.pumpWidget(MaterialApp(
        title: 'Foo App', // TODO change this
        localizationsDelegates: AppLocalizations.localizationsDelegates,
        supportedLocales: AppLocalizations.supportedLocales,
        locale: locale,
        debugShowCheckedModeBanner: false,
        home: Builder(builder: (context) {
          return const FooAppScreen(); // TODO change this
        })));

    await tester.pumpAndSettle();
  
    // TODO modify this to create a screenshot for your app
    // Here we go to the app's first tab and enter the text "USER INPUT"
    final tab1 = find.byKey(const Key('tab1'));
    expect(tab1, findsOneWidget);
    await tester.tap(tab1);
    await tester.pumpAndSettle();
  
    final input1 = find.byKey(const Key('input1'));
  
    expect(input1, findsOneWidget);
  
    await tester.enterText(input1, 'USER INPUT');
  
    await tester.pumpAndSettle();
  
    //generate screenshot
    await takeScreenShot(
        binding: binding,
        tester: tester,
        screenShotName: "screenshot-$locale-1");
    await tester.pumpAndSettle();
  });
  
  testWidgets('take screenshot 2', (WidgetTester tester) async {
    // TODO Do the same as above to navigate in your app towards the second screenshot

    //generate screenshot
    await takeScreenShot(
        binding: binding,
        tester: tester,
        screenShotName: "screenshot-$locale-2");
    await tester.pumpAndSettle();
  });

  // TODO Do the same for more screenshots. Ideally you want 3 or 4 screenshots in total.
}