Contributing¶

Thank you for your interest in contributing to the BESSER Web Modeling Editor! This section covers everything you need: from setting up your environment to submitting a pull request.

Tip

Not sure where to start? Browse open issues labeled good first issue, or pick an area below.

Quick Links¶

Understanding the Codebase — Understand the code: editor, webapp, server internals
Development Workflow — Install, run, test, and submit
Adding a New Diagram Type — Add a new diagram type (editor + webapp + backend)
CONTRIBUTING.md — Repository-level policy
Code of Conduct

Where to Contribute¶

Editor package (packages/editor): The reusable modeling engine. Add diagram types, element renderers, palette previews, property popups, or improve the ApollonEditor API.
Web application (packages/webapp): The React SPA. Improve project management, code generation integration, deployment flows, collaboration, or the UI.
Server (packages/server): The Express server. Improve diagram persistence, SVG-to-PDF export, or collaboration WebSocket handling.
Documentation (docs/): Fix errors, expand thin pages, add tutorials, or improve the Sphinx build.

Code Style¶

Language: TypeScript (strict mode), React with functional components.
Linting: ESLint configured per package. Run before every commit:
```
npm run lint
```
Formatting: Prettier configured at root. Check with:
```
npm run prettier:check
```
Naming: camelCase for variables and functions, PascalCase for components and types, UPPER_SNAKE_CASE for constants.
Commits: Use clear, descriptive messages. Prefer imperative mood (e.g., “Add state machine palette preview” not “Added…”).

Branching and PR Workflow¶

Fork the repository and clone locally.
Create a feature branch from main (e.g., feature/add-sequence-diagram).
Make focused, incremental commits.

Run the full check suite:

npm run lint
npm run test --workspace=webapp
npm run build

Push and open a pull request against main.
In the PR description, explain: what changed, why, how to test.
Respond to review feedback — reviews are collaborative.

Note

The WME repository uses main as its default branch (not master). The parent BESSER repository uses master.