# Contribution
## Introduction

It is assumed that you know a little about Node.js and Git. If not, [here's some help to get started with Git](https://help.github.com/en/github/using-git) and [here’s some help to get started with Node.js.](https://nodejs.org/en/docs/guides/getting-started-guide/)

* Install [Node.js](https://nodejs.org/)
* Install [Git](https://git-scm.com/)
* [Fork](https://help.github.com/en/github/getting-started-with-github/fork-a-repo) three.js
* Open your OS’s terminal
* Change into the directory you’d like
* Clone your forked repo

      git clone https://github.com/[yourgithubname]/three.js.git

* Go into the three.js directory.

      cd ./three.js

* Install the dependencies

      npm install

## Next Steps

As per the npm standard, ‘start’ is the place to begin the package.

    npm start

This script will start a local server similar to [threejs.org](https://threejs.org/), but instead will be hosted on your local machine. Browse to https://localhost:8080/ to check it out. It also automatically creates the `build/three.module.js` script anytime there is a change `src` directory.

Next scripts run all the appropriate testing.

- `npm run test` - Lint testing and unit testing (individually being `npm run lint` and `npm run test-unit`)
- `npm run test-e2e` - E2E testing. This one can take quite a long time and installs ~200 MB Chromium browser - it is primarily intended to be run only by GitHub Actions

The linting is there to keep a consistent code style across all of the code and the testing is there to help catch bugs and check that the code behaves as expected. It is important that neither of these steps comes up with any errors due to your changes.

Most linting errors can be fixed automatically by running

    npm run lint-fix

If you’d like to make a build of the source files (e.g. `build/three.module.js`) run:

    npm run build

## Making changes

When you’ve decided to make changes, start with the following:

* Update your local repo

      git pull https://github.com/mrdoob/three.js.git
      git push

* Make a new branch from the dev branch

      git checkout dev
      git branch [mychangesbranch]
      git checkout [mychangesbranch]

* Add your changes to your commit.
* Push the changes to your forked repo.
* Open a Pull Request (PR)

## Important notes:

* Don't include any build files in your commit.
* Not all new features will need a new example. Simpler features could be incorporated into an existing example. Bigger features may be asked to add an example demonstrating the feature.
* Making changes may require changes to the documentation. To update the docs in other languages, simply copy the English to begin with.
* It's good to also add an example and screenshot for it, for showing how it's used and for end-to-end testing.
* If you modify existing code, run relevant examples to check they didn't break and there wasn't performance regress.
* If you add some assets for the examples (models, textures, sounds, etc), make sure they have a proper license allowing for their use here, less restrictive the better. It is unlikely for large assets to be accepted.
* If some issue is relevant to the patch/feature, please mention it with a hash (e.g. #2774) in a commit message to get cross-reference in GitHub.
* If the end-to-end test failed and you are sure that all is correct, follow the instructions it outputs.
* Once done with a patch/feature do not add more commits to a feature branch.
* Create separate branches per patch or feature.
* If you make a PR but it is not actually ready to be pulled into the dev branch then please [convert it to a draft PR](https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/changing-the-stage-of-a-pull-request#converting-a-pull-request-to-a-draft).

This project is currently contributed mostly via everyone's spare time. Please keep that in mind as it may take some time for the appropriate feedback to get to you. If you are unsure about adding a new feature, it might be better to ask first to see whether other people think it's a good idea.