Renames MyApp and MainApp to App in the Flutter app templates

rename_flutter_app_class.sh

#!/bin/bash

# Get the location of the Flutter SDK
flutter_path=$(which flutter)

# Check if Flutter SDK is found
if [[ -z "$flutter_path" ]]; then
    echo "Flutter SDK not found. Please install Flutter and add it to your PATH."
    exit 1
fi

flutter_path=${flutter_path%/*/*}

# Get the path to the file to be patched
file_to_patch="$flutter_path/packages/flutter_tools/templates/app/lib/main.dart.tmpl"

# Check if the file exists
if [[ ! -f "$file_to_patch" ]]; then
    echo "File not found!"
    exit 1
fi

# Use awk to replace all instances of MyApp and MainApp to App
echo "Creating patch for ${file_to_patch}"

awk '
{ gsub("MyApp","App"); gsub("MainApp","App"); print }
' "$file_to_patch" > temp

# Show a diff before patching
echo "Here is the proposed change:"
diff --color -u "$file_to_patch" temp

# Ask the user if they want to proceed
read -p "Do you want to apply these changes? (y/n) " answer
case ${answer:0:1} in
    y|Y )
        echo "Applying changes..."
        mv temp "$file_to_patch"
    ;;
    * )
        echo "Aborting..."
        rm temp
    ;;
esac

Run this every time you update the SDK. Use it with flutter create -e myapp to generate a minimal lib/main.dart.

Before:

import 'package:flutter/material.dart';

void main() {
  runApp(const MainApp());
}

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: Scaffold(
        body: Center(
          child: Text('Hello World!'),
        ),
      ),
    );
  }
}

After:

import 'package:flutter/material.dart';

void main() {
  runApp(const App());
}

class App extends StatelessWidget {
  const App({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: Scaffold(
        body: Center(
          child: Text('Hello World!'),
        ),
      ),
    );
  }
}