code-generation

name	code-generation
description	Execute code generation for created source files. Handles build_runner (freezed, json_serializable, retrofit, auto_route, theme_tailor, flutter_gen) and localization via Melos. Use after creating or modifying source files that require code generation.

Code Generation Skill

When to Use

After creating or modifying source files that contain part directives for generated files (.g.dart, .freezed.dart, .gr.dart, .tailor.dart) or localization .arb files.

Prerequisites

• All source files are saved with correct annotations and part directives
• No syntax errors in source files
• Dependencies bootstrapped (make bootstrap)

Execution

1. Choose Generation Scope

Scoped (preferred) — fastest, use when you changed a few files and want to regenerate only specific outputs.

--build-filter filters output files (.g.dart, .freezed.dart, etc.), not source files. It accepts glob patterns. The path is relative to the project root — the package is auto-resolved from the path prefix.

# Single output file
make gen-scope scope="apps/main/lib/feature/auth/domain/entity/user.g.dart"

# All freezed outputs in a folder
make gen-scope scope="apps/main/lib/feature/auth/**/*.freezed.dart"

# All generated outputs for a specific source (matches user.g.dart, user.freezed.dart, etc.)
make gen-scope scope="apps/main/lib/feature/auth/domain/entity/user.*.dart"

# All generated outputs in a module
make gen-scope scope="modules/datasource/network/lib/**/*.g.dart"

# Multiple generator types via brace expansion
make gen-scope scope="apps/main/lib/feature/auth/**/*.{g,freezed}.dart"

Parameters:

• scope — glob pattern for generated output files, relative to the project root. The package root (pubspec.yaml) is auto-resolved from the path prefix.

Module-scoped — use when many files in one module changed:

make gen-app           # apps/main (freezed, json_serializable, retrofit, auto_route, flutter_gen)
make gen-ui            # modules/ui (theme_tailor, flutter_gen + localization)
make gen-network       # modules/datasource/network (json_serializable, retrofit)
make gen-persistence   # modules/datasource/persistence (json_serializable)

All modules — use when changes span multiple modules:

make gen-all

Localization only — after modifying .arb files in modules/ui/lib/l10n/:

make gen-l10n

2. Verify Results

• Check expected generated files exist and are non-empty
• Review command output for errors

3. Handle Failures

CRITICAL: NEVER modify generated files directly.

If generation fails:

1. Fix syntax/annotation errors in source files only
2. Delete problematic generated file if corrupted
3. Re-run generation

For verbose output: add --verbose flag to the underlying build_runner command.

Module Structure

This is a Melos monorepo. Each module runs build_runner independently.

Important: build.yaml does NOT inherit from parent directories. Every module using code generation must have its own build.yaml.

Module	Path	Generators
app	apps/main	freezed, json_serializable, retrofit, auto_route
ui	modules/ui	theme_tailor, flutter_gen, gen-l10n
network	modules/datasource/network	json_serializable, retrofit
persistence	modules/datasource/persistence	json_serializable, drift

Output

### Code Generation Results

**Command:** {executed command}
**Scope:** {scope pattern, module name, or "all"}

| Source File | Generated File | Status |
|-------------|----------------|--------|
| path/to/source.dart | path/to/source.g.dart | SUCCESS |

**Issues:** {any warnings or errors, or "None"}
**Final status:** SUCCESS / FAILED