[gen_l10n.dart] `.arb`descriptions get mistaken as code

[hanneskoksch]

Descriptions of Strings in .arb files including line breaks (\n) get mistaken as code.

The file translations_en.arb

{
    "welcome": "Welcome to the app",
    "@welcome": {
        "description": "This message gets displayed on the first page.\nUse it in caps.",
        "type": "text"
    },
}

...results in app_localizations.dart

  /// This message gets displayed on the first page.
Use it in caps.
  ///
  /// In en, this message translates to:
  /// **'Welcome to the app'**
  String get welcome;

Instead, I would expect this result:

  /// This message gets displayed on the first page.\nUse it in caps.
  ///
  /// In en, this message translates to:
  /// **'Welcome to the app'**
  String get welcome;

or

  /// This message gets displayed on the first page.
  /// Use it in caps.
  ///
  /// In en, this message translates to:
  /// **'Welcome to the app'**
  String get welcome;

I can see, that the error occurs here:

flutter/packages/flutter_tools/lib/src/localizations/gen_l10n.dart

Line 204 in 2c4051f

final String comment = message.description ?? 'No description provided for @${message.resourceId}.';

[exaby73]

Hello @hanneskoksch. Thank you for filing this issue. Can you please provide the following information?

• A complete and minimal, reproducible example. Ideally, a single main.dart file that can be run directly.
• The output of flutter doctor -v

Please provide the information in the form of text. See how to make collapsible sections with Markdown here.

[SunlightBro]

@exaby73

How to reproduce

# [skeleton] uses gen_l10n
flutter create -t skeleton gen_l10n_example
cd gen_l10n_example

# edit app_en.arb with sed on [macos]
sed -i '' 's/application/application\'$'\\nLinebreak does not work/g' lib/src/localization/app_en.arb

# flutter packages get also creates the synthetic_package
flutter packages get

# flutter build fails
flutter build apk

flutter build apk

💪 Building with sound null safety 💪

.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:11: Error: Expected ';' after this.
Linebreak does not work
          ^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:20: Error: Expected ';' after this.
Linebreak does not work
                   ^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:1: Error: Type 'Linebreak' not found.
Linebreak does not work
^^^^^^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:16: Error: Type 'not' not found.
Linebreak does not work
               ^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:1: Error: 'Linebreak' isn't a type.
Linebreak does not work
^^^^^^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:16: Error: 'not' isn't a type.
Linebreak does not work
               ^^^


FAILURE: Build failed with an exception.

* Where:
Script '/Users/sunbro/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 1159

* What went wrong:
Execution failed for task ':app:compileFlutterBuildRelease'.
> Process 'command '/Users/sunbro/flutter/bin/flutter'' finished with non-zero exit value 1

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 5s
Running Gradle task 'assembleRelease'...                            6.5s
Gradle task assembleRelease failed with exit code 1

sed only works this way on macos, if you are on a different OS simply replace the app_en.arb:

app_en.arb

{
  "appTitle": "gen_l10n",
  "@appTitle": {
-    "description": "The title of the application"
+    "description": "The title of the application\nLinebreak does not work"
  }
}

flutter doctor -v

[✓] Flutter (Channel stable, 3.3.8, on macOS 13.0.1 22A400 darwin-arm, locale en-DE)
    • Flutter version 3.3.8 on channel stable at /Users/sunbro/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 52b3dc25f6 (6 days ago), 2022-11-09 12:09:26 +0800
    • Engine revision 857bd6b74c
    • Dart version 2.18.4
    • DevTools version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0-rc1)
    • Android SDK at /Users/sunbro/Library/Android/sdk
    • Platform android-33, build-tools 33.0.0-rc1
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.13+0-b1751.21-8125866)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 14.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14B47b
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.13+0-b1751.21-8125866)

[✓] IntelliJ IDEA Community Edition (version 2022.2)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart

[✓] Connected device (3 available)
    • ONEPLUS A6003 (mobile) • b0a181c6 • android-arm64  • Android 11 (API 30)
    • macOS (desktop)        • macos    • darwin-arm64   • macOS 13.0.1 22A400 darwin-arm
    • Chrome (web)           • chrome   • web-javascript • Google Chrome 107.0.5304.110

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!

[exaby73]

Triage report

I can reproduce this issue with the steps provided in #115295 (comment) on Master (3.6.0-3.0.pre.20).

flutter build apk Error logs

💪 Building with sound null safety 💪

Running Gradle task 'assembleRelease'...
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:11: Error: Expected ';' after this.
Linebreak does not work
          ^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:20: Error: Expected ';' after this.
Linebreak does not work
                   ^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:1: Error: Type 'Linebreak' not found.
Linebreak does not work
^^^^^^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:16: Error: Type 'not' not found.
Linebreak does not work
               ^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:1: Error: 'Linebreak' isn't a type.
Linebreak does not work
^^^^^^^^^
.dart_tool/flutter_gen/gen_l10n/app_localizations.dart:95:16: Error: 'not' isn't a type.
Linebreak does not work
               ^^^
Target kernel_snapshot failed: Exception


FAILURE: Build failed with an exception.

* Where:
Script '/home/exabyt3/fvm/versions/master/packages/flutter_tools/gradle/flutter.gradle' line: 1151

* What went wrong:
Execution failed for task ':app:compileFlutterBuildRelease'.
> Process 'command '/home/exabyt3/fvm/versions/master/bin/flutter'' finished with non-zero exit value 1

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 7s
Running Gradle task 'assembleRelease'...                            8.2s
Gradle task assembleRelease failed with exit code 1

[christopherfujino]

@thkim1011 can you take a look at this one?