Mason Brick Development Skill

This skill guides the creation, modification, and removal of Mason bricks, ensuring test coverage and CI workflow integration.

When to Use

Trigger this skill when:

• Creating a new Mason brick template
• Updating an existing brick's structure or variables
• Removing a brick from the project
• User asks to "create a brick", "add a mason template", "update brick", or "remove brick"

Project Structure

Bricks are organized in three locations:

bricks/                    # Mason template definitions
├── brick_name/
│   ├── brick.yaml         # Brick configuration and variables
│   ├── __brick__/         # Template files with Mustache syntax
│   └── hooks/             # Optional pre/post generation hooks

test_bricks/               # Brick tests (one folder per brick)
├── brick_name/
│   └── brick_name_test.dart

.github/workflows/
└── brick-test.yml         # Parallel CI jobs for each brick

Creating a New Brick

Step 1: Create Brick Directory

mkdir -p bricks/new_brick/__brick__

Step 2: Create brick.yaml

name: new_brick
description: Description of what this brick generates
version: 0.1.0+1

environment:
  mason: ^0.1.1

vars:
  name:
    type: string
    description: The name for the generated component
    prompt: What is the name?

  # Add more variables as needed
  optional_var:
    type: boolean
    description: Optional feature flag
    default: true

Step 3: Create Template Files

In

__brick__/

__brick__/
├── {{name.snakeCase()}}/
│   ├── lib/
│   │   └── {{name.snakeCase()}}.dart
│   ├── pubspec.yaml
│   └── README.md

Use these Mustache helpers:

• {{name}}

  - raw value

• {{name.snakeCase()}}

  - snake_case

• {{name.pascalCase()}}

  - PascalCase

• {{name.camelCase()}}

  - camelCase

• {{name.paramCase()}}

  - param-case

• {{#flag}}...{{/flag}}

  - conditional block

• {{^flag}}...{{/flag}}

  - inverted conditional

Step 4: Create Brick Test

Create

test_bricks/new_brick/new_brick_test.dart

import 'dart:io';
import 'package:mason/mason.dart';
import 'package:path/path.dart' as path;
import 'package:test/test.dart';

void main() {
  group('New Brick Tests', () {
    late Directory tempDir;

    setUp(() async {
      tempDir = await Directory.systemTemp.createTemp('new_brick_test_');
    });

    tearDown(() async {
      if (await tempDir.exists()) {
        await tempDir.delete(recursive: true);
      }
    });

    test('generates correct structure', () async {
      final brick = Brick.path(path.join('..', '..', 'bricks', 'new_brick'));

      final generator = await MasonGenerator.fromBrick(brick);
      await generator.generate(
        DirectoryGeneratorTarget(tempDir),
        vars: {'name': 'test_name'},
      );

      // Verify generated files exist
      final file = File(path.join(tempDir.path, 'test_name', 'pubspec.yaml'));
      expect(await file.exists(), isTrue);
    });

    // Add more tests for different variable combinations
  });
}

Step 5: Add Workflow Job

Add a new job to

.github/workflows/brick-test.yml

  new-brick:
    name: Test new_brick
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6

      - uses: flutter-actions/setup-flutter@v4

      - name: Cache dependencies
        uses: actions/cache@v5
        with:
          path: |
            ~/.pub-cache
            .dart_tool
          key: ${{ runner.os }}-pub-${{ hashFiles('**/pubspec.lock') }}
          restore-keys: ${{ runner.os }}-pub-

      - name: Install tools
        run: dart pub global activate melos

      - name: Prepare project
        run: |
          melos run prepare
          mason get

      - name: Test new_brick brick
        run: dart run test_bricks/new_brick/new_brick_test.dart

Step 6: Register Brick

Add to root

mason.yaml

bricks:
  new_brick:
    path: bricks/new_brick

Then run

mason get

Updating an Existing Brick

When modifying a brick:

1. Update

   brick.yaml

   if adding/removing variables
2. Update template files in

   __brick__/

3. Update tests in

   test_bricks/brick_name/

   to cover changes
4. Run test locally:

   dart run test_bricks/brick_name/brick_name_test.dart

5. Increment version in

   brick.yaml

Removing a Brick

When removing a brick, update all three locations:

1. Remove brick directory:

   rm -rf bricks/brick_name

2. Remove test directory:

   rm -rf test_bricks/brick_name

3. Remove workflow job from

   .github/workflows/brick-test.yml

4. Remove from

   mason.yaml

5. Update CLAUDE.md if the brick was documented

Testing Locally

# Register bricks
mason get

# Test a specific brick
dart run test_bricks/brick_name/brick_name_test.dart

# Test brick generation manually
mason make brick_name -o /tmp/test_output --var1=value1

Existing Bricks Reference

screen

name

folder

has_adaptive_scaffold

widget

name

type

folder

simple_bloc

name

list_bloc

name

form_bloc

name

field_names

repository

name

api_client

package_name

native_federation_plugin

name

package_prefix

support_*

Checklist

When creating/updating a brick:

• brick.yaml

  has name, description, version, and vars
• Template files use correct Mustache syntax
• Test file exists in

  test_bricks/brick_name/

• Tests cover main generation paths
• Workflow job added/updated in

  brick-test.yml

• Brick registered in

  mason.yaml

• Run

  mason get

  to verify registration
• Run test locally before committing