Patisserie

Language-agnostic boilerplate code generator from YAML data models and Jinja2 templates.

Define your data model once in YAML. Generate boilerplate code in any language (Java, Rust, Python, Go, TypeScript, etc.) using Jinja2 templates.

Why Pattiserie?

• Single Source of Truth: Define your data model once, generate code for multiple languages
• Template-Driven: Use Jinja2 to create language-specific templates
• Configuration as Code: YAML schemas with anchors for DRY configuration
• Language Agnostic: Generate Java, Rust, Python, Go, TypeScript, or any text-based format
• Zero Runtime Dependencies: Just Python, PyYAML, and Jinja2

Quick Start

Installation

pip install patisserie

5-Minute Example

1. Initialize a project:

   mkdir my-project && cd my-project pati mise

The pati mise command will create the .pati directory for you and create the sample schema.yaml and templates files you can edit.

2. Edit your data model (.pati/schema.yaml):

   jobs:
     user_entity:
       template: entity.java.j2
       output: generated/User.java
       context:
         package: com.example
         class_name: User
         fields:
           - name: id
             type: Long
           - name: username
             type: String
   

3. Customize a template (.pati/tmplts/entity.java.j2):

   package {{ package }};
   
   public class {{ class_name }} {
   {% for field in fields %}
       private {{ field.type }} {{ field.name }};
   {% endfor %}
   }
   

4. Generate code:

   pati cuire
   

5. Check the output:

   cat generated/User.java
   

Features

📋 YAML Schema Support

• Define jobs with template, output, and context
• YAML anchors (&name) and aliases (*name) for reusable config
• Merge key (<<: *alias) for DRY configuration
• Full PyYAML support for complex structures

🎨 Jinja2 Templates

• Variables: {{ variable }}
• Loops: {% for item in items %}
• Conditionals: {% if condition %}
• Filters: {{ value | filter }}
• Complete Jinja2 feature set

🛠️ CLI Tools

# Generate all jobs from default schema (.pati/schema.yaml)
pati cuire

# Generate specific job(s) by name
pati cuire pojo_user

# Generate jobs matching a glob pattern
pati cuire 'pojo*'

# Generate jobs matching multiple patterns
pati cuire 'pojo*' dto_user

# Generate from a specific schema
pati cuire --config path/to/schema.yaml

# Dry run (preview without writing)
pati cuire --dry-run

# Override output directory
pati cuire --output-dir /path/to/output

# Initialize new project, creating a sample yaml
# and the sample template files in the directory .pati
pati mise

📦 Built-in Examples

• Java Spring Boot: Entities, DTOs, Repositories, Liquibase migrations
• Rust SQLx: Models with SQLx derive macros
• Python SQLAlchemy: ORM models
• Go GORM: Struct definitions with GORM tags

These examples are for demonstration purpose only. They are simplified. Real word examples can start from these templates, but they will likely be extended.

Documentation

• Installation Guide — Setup and troubleshooting
• Quick Start Guide — Get running in 5 minutes
• YAML Schema Reference — Complete schema documentation
• Jinja2 Template Syntax — Template language reference
• Real-World Examples — Complete working examples
• Why Pâtisserie? — The philosophy behind the name

Example Use Cases

Multi-language ORM Models

jobs:
  user_java:
    template: entity.java.j2
    output: src/main/java/User.java
    context: { class_name: User, fields: [...] }
  
  user_python:
    template: model.py.j2
    output: models/user.py
    context: { class_name: User, fields: [...] }
  
  user_rust:
    template: model.rs.j2
    output: src/models/user.rs
    context: { struct_name: User, fields: [...] }

Microservice Scaffolding

Generate controllers, services, and DTOs from a single data model schema.

API Client/Server Code

Generate OpenAPI specs, request/response models, and route handlers.

Database Migrations

Generate SQL migrations, Liquibase changesets, or Flyway migrations.

Configuration Files

Generate Docker Compose, Kubernetes manifests, or Terraform code.

Architecture

schema.yaml          Template files              Generated code
     │               (Jinja2)                         │
     │                   │                            │
     └──────────────────────────────────────────────────→
                    pati
          (config loader + generator)

1. Load YAML schema
2. Extract job configuration
3. Initialize Jinja2 environment
4. Render each template with context
5. Write generated files

Development

This chapter is about how to develop the code of Pâtisserie itself.

Setup

git clone https://github.com/yourusername/pati.git
cd pati
pip install -e ".[dev]"

Running Tests

pytest tests/ -v --cov

Building

./build.sh

Releasing

./release.sh 0.2.0

CLI Reference

# Generate from default schema
pati cuire [JOB ...] [OPTIONS]     # French: "to bake"
pati generate [JOB ...] [OPTIONS]  # English alias — identical
  JOB                     Job name(s) or glob patterns to run (default: all)
                          Examples: pojo_user  'pojo*'  'pojo*' dto_user
  --config, -c FILE       Path to schema file (default: .pati/schema.yaml)
  --dry-run               Show what would be generated without writing
  --output-dir DIR        Override output directory for all jobs

# Initialize new project structure
pati mise [OPTIONS]       # French: "mise en place"
pati init [OPTIONS]       # English alias — identical
  --output, -o DIR        Output directory (default: current directory)

# Show version
pati --version, -v

# Logging level (global flags, mutually exclusive)
pati --verbose COMMAND   # debug output
pati --quiet COMMAND     # warnings and errors only
pati -q COMMAND
pati --silent COMMAND    # errors only
pati -s COMMAND

# Show help
pati --help
pati COMMAND --help

Project Structure

pati/
├── src/pati/           # Main package
│   ├── __init__.py          # Package metadata
│   ├── cli.py               # CLI entry point
│   ├── config.py            # YAML config loader
│   ├── generator.py         # Template generator
│   └── utils.py             # Helper functions
├── examples/                # Example templates
│   ├── java-spring/
│   ├── rust-sqlx/
│   ├── python-sqlalchemy/
│   └── go-gorm/
├── tests/                   # Test suite
├── docs/                    # Documentation
├── setup.py                 # Package metadata
├── pyproject.toml          # Modern Python config
├── build.sh                 # Build script
└── release.sh              # Release script

License

Licensed under either of:

• MIT License
• Apache License, Version 2.0

at your option.

Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create a feature branch
3. Write tests for new features
4. Ensure tests pass: pytest tests/ -v --cov
5. Submit a pull request

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions
• Docs: Full Documentation

Roadmap

• Watch mode for live template development
• Template inheritance and includes
• Custom Jinja2 filters and globals
• Schema validation with JSON Schema
• Plugin system for extensibility
• Web UI for template editing
• Template marketplace

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Ready to generate? → Quick Start Guide