Feature Gen

Feature Gen is a Dart CLI that scaffolds clean-architecture feature modules for Flutter projects from a JSON schema.

Requirements

• Dart SDK >=3.10.4
• A Flutter project with a valid pubspec.yaml
• dart available on your PATH

Installation

dart pub global activate feature_gen_cli

Quick Start

1. From your Flutter project root, create a schema file (see example/user_schema.json).
2. Run the generator:

feature_gen_cli user schema.json

This creates lib/features/user/ plus supporting files, installs missing deps, runs build_runner, and formats the generated code.

Usage

feature_gen_cli <feature_name> <schema.json>

Flags

Flag	Description
-h, --help	Show usage information
-v, --version	Print the current version

Example

feature_gen_cli user example/user_schema.json

Schema Reference

The schema is a single JSON file with three required sections: config, api.methods, and response.

Minimal Schema

{
  "config": { "bloc": true, "riverpod": false },
  "api": { "methods": { "getUser": {} } },
  "response": { "id": "int", "name": "string" }
}

config

Exactly one of these must be true:

• bloc generates BLoC + Event + State.
• riverpod generates a Riverpod Notifier.

api.methods

Each key is a method name (camelCase). Each method may include any of:

• params path parameters
• body request body fields
• query query parameters

A method that defines at least one of params, body, or query will also get a generated UseCase and params classes. Empty methods still generate the repository + datasource wiring.

Example:

{
  "api": {
    "methods": {
      "getUser": {},
      "updateUser": {
        "body": { "name": "string", "email": "string" }
      },
      "deleteUser": {
        "params": { "id": "int" }
      }
    }
  }
}

response

Defines the base entity/model fields. Keys are field names; values are types.

List responses are expressed by wrapping the response object in an array:

{ "response": [ { "id": "int", "name": "string" } ] }

Supported Types

Schema Value	Dart Type
"string"	String
"int"	int
"double"	double
"bool"	bool
"list"	List<dynamic>
"map"	Map<String, dynamic>
{ ... }	Custom model
[{ ... }]	List<CustomModel>

You can also use literal JSON values (e.g. 123 → int, true → bool). Nested objects and lists of objects are automatically lifted into their own Freezed models/entities based on the field name.

Naming Conventions

• feature_name is expected to be snake_case (used for folder names and class conversions).
• Method keys in api.methods should be camelCase (used to generate class and file names).

Generated Structure

Running feature_gen_cli user schema.json produces:

lib/
├── core/
│   └── di/
│       └── injector.dart
└── features/user/
├── data/
│   ├── datasources/
│   │   └── user_remote_datasource.dart
│   ├── models/
│   │   └── user_model.dart
│   └── repositories/
│       └── user_repository_impl.dart
├── domain/
│   ├── entities/
│   │   └── user_entity.dart
│   ├── repositories/
│   │   └── user_repository.dart
│   └── usecases/
│       ├── get_user_usecase.dart
│       ├── update_user_usecase.dart
│       └── delete_user_usecase.dart
└── presentation/
    ├── bloc/ (if enabled)
    │   ├── user_bloc.dart
    │   ├── user_event.dart
    │   └── user_state.dart
    ├── riverpod/ (if enabled)
    │   └── user_notifier.dart
    └── screen/
        └── user_screen.dart

If any method has params/body/query, a shared base use-case is also created at:

lib/features/shared/usecase/base_usecase.dart

What the CLI Changes

• Adds missing dependencies using dart pub add.
• Generates files in lib/features/<feature_name>/ and lib/core/di/injector.dart.
• Runs dart run build_runner build -d.
• Formats the generated feature directory with dart format.
• Overwrites any previously generated files with the same paths.

Troubleshooting

• Schema validation errors: ensure config, api.methods, and response exist, and that exactly one of config.bloc or config.riverpod is true.
• build_runner failed: re-run it manually in your project root:

dart run build_runner build -d

• Dependencies not added: check that you have write access to pubspec.yaml and that dart pub add succeeds in the same project.

Project Structure

feature_gen/
├── bin/feature_gen_cli.dart        # CLI entry point
├── lib/
│   ├── feature_gen.dart            # Pipeline orchestrator
│   ├── parser.dart                 # JSON schema parser & context builder
│   ├── generator.dart              # Directory creation & template rendering
│   ├── command_runner.dart         # Shell command execution (deps, build, format)
│   ├── command_helper.dart         # Styled console output (errors, success, warnings)
│   ├── types.dart                  # Data models (Schema, Context, etc.)
│   ├── string_extension.dart       # Case-conversion utilities
│   ├── yaml_helper.dart            # pubspec.yaml reader
│   └── template/                   # Mustache template files
└── pubspec.yaml

Contributing

• Install dependencies with dart pub get.
• Run tests with dart test.
• Keep formatting clean with dart format ..

License

MIT