Contributing

Thanks for your interest in @emaarco/dmn-js-simulation! Contributions of all kinds are welcome — bug reports, feature ideas, docs, and code.

Getting started

git clone https://github.com/emaarco/dmn-js-simulation.git
cd dmn-js-simulation
npm install
npm test

The repository is an npm-workspaces monorepo:

• packages/dmn-js-simulation — the published library
• packages/example — an example dmn-js modeler

Scripts

npm test              # unit tests (Vitest)
npm run typecheck     # tsc --noEmit
npm run lint          # ESLint
npm run lint:deps     # dependency-cruiser architecture check
npm run build         # build the library (Rollup → ESM + CJS + d.ts + CSS)
npm run dev           # run the example modeler (Vite)
npm run test:e2e      # Playwright E2E against the example app

Ground rules

• Conventional Commits. Commit messages and PR titles follow Conventional Commits (feat:, fix:, docs:, refactor:, test:, chore:). Releases and the changelog are generated from them via release-please.
• Keep the layering intact. The library is split into domain/ (pure evaluation, no dmn-js/DOM), adapter/, simulation/, ui/ and integration/. Imports only ever point "down"; npm run lint:deps (dependency-cruiser) enforces this in CI.
• Add tests. Evaluation logic and hit policies are covered by Vitest unit tests; please extend them for any behavior change.

Before opening a PR

npm run typecheck
npm run lint
npm run lint:deps
npm test
npm run build

All of these run in CI on Node 22 and 24 (Node 22 also runs the Playwright E2E suite).

Reporting bugs / requesting features

Use the GitHub issue templates. For decision-logic bugs, attaching the .dmn file and the inputs you simulated is the fastest path to a fix.