CONTRIBUTING.md

Contributing to Nx

We would love for you to contribute to Nx! Read this document to see how to do it.

How to Get Started Video

Watch this 5-minute video:

Got a Question?

We are trying to keep GitHub issues for bug reports and feature requests. Using the nrwl tag on Stack Overflow is a much better place to ask general questions about how to use Nx.

Found an Issue?

If you find a bug in the source code or a mistake in the documentation, you can help us by submitting an issue to our GitHub Repository. Even better, you can submit a Pull Request with a fix.

Project Structure

Source code and documentation are included in the top-level folders listed below.

• docs - Markdown and configuration files for documentation including tutorials, guides for each supported platform, and API docs.
• e2e - E2E tests.
• packages - Source code for Nx packages such as Angular, React, Web, NestJS, Next and others including generators and executors (or builders).
• scripts - Miscellaneous scripts for project tasks such as building documentation, testing, and code formatting.
• tmp - Folder used by e2e tests. If you are a WebStorm user, make sure to mark this folder as excluded.

Building the Project

Nx uses Rust to build native bindings for Node. Please make sure that you have Rust installed via rustup.rs

After cloning the project to your machine, to install the dependencies, run:

yarn

To build all the packages, run:

yarn build

Publishing to a local registry

To test if your changes will actually work once the changes are published, it can be useful to publish to a local registry.

Check out this video for a live walkthrough or follow the instructions below:

• Run yarn local-registry start in Terminal 1 (keep it running)
• Run npm adduser --registry http://localhost:4873 in Terminal 2 (real credentials are not required, you just need to be logged in. You can use test/test/test@test.io.)
• Run yarn local-registry enable in Terminal 2
• Run yarn nx-release 16.0.0 --local in Terminal 2 - you can choose any nonexistent version number here, but it's recommended to use the next major
• Run cd ./tmp in Terminal 2
• Run npx create-nx-workspace@16.0.0 in Terminal 2

If you have problems publishing, make sure you use Node 18 and NPM 8.

NOTE: After you finish with local testing don't forget to stop the local registry (e.g. closing the Terminal 1) and disabling the local registy using yarn local-registry disable. Keeping local registry enabled will change your lock file resolutions to localhost:4873 on the next yarn install. You can also run yarn local-registry clear to clean all packages in that local registry.

NOTE: To use this newly published local version, you need to make a new workspace or change all of your target packages to this new version, eg: "@nrwl/cli": "^16.0.0", and re-run yarn install in your testing project.

Publishing for Yarn 2+ (Berry)

Yarn Berry operates slightly differently than Yarn Classic. In order to publish packages for Berry follow next steps:

• Run yarn set version berry to switch to latest Yarn version.

• Create .yarnrc.yml in root with following contents:

  nodeLinker: node-modules
  npmRegistryServer: 'http://localhost:4873'
  unsafeHttpWhitelist:
    - localhost

• Run yarn local-registry start in Terminal 1 (keep it running)

• If you are creating nx workspace outside of your nx repo, make sure to add npm registry info to your root yarnrc ( usually in ~/.yarnrc.yml). The file should look something like this:

  npmRegistries:
    'https://registry.yarnpkg.com':
      npmAuthToken: npm_******************
  yarnPath: .yarn/releases/yarn-3.2.2.cjs
  
  npmRegistryServer: 'http://localhost:4873'
  unsafeHttpWhitelist:
    - localhost

• Run yarn nx-release --local in Terminal 2 to publish next minor version. If this version already exists, you can bump the minor version in lerna.json to toggle the next minor. The output will report the version of published packages.

• Go to your target folder (e.g. cd ./tmp) in Terminal 2

• Run yarn dlx create-nx-workspace@123.4.5 in Terminal 2 (replace 123.4.5 with the version that got published).

Running Unit Tests

To make sure your changes do not break any unit tests, run the following:

nx affected --target=test

For example, if you need to only run the tests for the jest package, run:

nx test jest

Running E2E Tests

Use Node 18 and NPM 8. E2E tests won't work on Node 15 and NPM 7.

To make sure your changes do not break any E2E tests, run:

nx e2e e2e-cli # or any other project here

Running E2E tests can take some time, so it is often useful to run a single test. To run a single suite of tests, run:

nx e2e e2e-cli -t versions # I often add qqqq to my test name so I can use -t qqqq

Sometimes tests pass locally but they fail on the CI. To reproduce the CI environment and be able to debug the issue, run:

NX_VERBOSE_LOGGING=true CI=true SELECTED_PM=pnpm yarn nx e2e e2e-cli --t="should do something is this test"

The above command sets verbose logging (this exposes stack traces and underlying errors), sets the defaults to be CI-like and sets Pnpm as the selected package manager.

Developing on Windows

To build Nx on Windows, you need to use WSL.

• Run yarn install in WSL. Yarn will compile several dependencies. If you don't run install in WSL, they will be compiled for Windows.
• Run nx affected --target=test and other commands in WSL.

Documentation Contributions

We would love for you to contribute to our documentation as well! Please feel welcome to submit fixes or enhancements to our existing documentation pages and the nx-dev application in this repo.

Documentation Structure

Documentation Pages

Our documentation pages can be found within this repo under the docs directory.

The docs/map.json file is considered our source of truth for our site's structure, and should be updated when adding a new page to our documentation to ensure that it is included in the documentation site. We also run automated scripts based on this map.json data to safeguard against common human errors that could break our site.

Nx-Dev Application

Our public nx.dev documentation site is a Next.js application, that can be found in the nx-dev directory of this repo. The documentation site is consuming the docs/ directly by copy-ing its content while deploying, so the website is always in sync and reflects the latest version of docs/.

Jump to Running the Documentation Site Locally to see how to preview your changes while serving.

Changing Generated API documentation

.md files documenting the API for our CLI (including executor and generator API docs) are generated via the corresponding schema.json file for the given command.

After adjusting the schema.json file, .md files for these commands can be generated by running:

yarn documentation

This will update the corresponding contents of the docs directory. These are generated automatically on push (via husky) as well.

Note that adjusting the schema.json files will also affect the CLI manuals and Nx Console behavior, in addition to adjusting the docs.

Running the Documentation Site Locally

To run nx-dev locally, run the command:

npx nx serve nx-dev

You can then access the application locally at localhost:4200.

Troubleshooting: JavaScript heap out of memory

If you see an error that states: FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory, you need to increase the max memory size of V8's old memory section:

export NODE_OPTIONS="--max-old-space-size=4096"

After configuring this, try to run npx nx serve nx-dev again.

PR Preview

When submitting a PR, this repo will automatically generate a preview of the nx-dev application based on the contents of your pull request.

Once the preview site is launched, a comment will automatically be added to your PR with the link your PR's preview. To check your docs changes, make sure to select Preview from the version selection box of the site.

Submission Guidelines

Submitting an Issue

Before you submit an issue, please search the issue tracker. An issue for your problem may already exist and has been resolved, or the discussion might inform you of workarounds readily available.

We want to fix all the issues as soon as possible, but before fixing a bug we need to reproduce and confirm it. Having a reproducible scenario gives us wealth of important information without going back and forth with you requiring additional information, such as:

• the output of nx report
• yarn.lock or package-lock.json
• and most importantly - a use-case that fails

A minimal reproduction allows us to quickly confirm a bug (or point out a coding problem) as well as confirm that we are fixing the right problem.

We will be insisting on a minimal reproduction in order to save maintainers' time and ultimately be able to fix more bugs. Interestingly, from our experience, users often find coding problems themselves while preparing a minimal reproduction repository. We understand that sometimes it might be hard to extract essentials bits of code from a larger codebase, but we really need to isolate the problem before we can fix it.

You can file new issues by filling out our issue form.

Submitting a PR

Please follow the following guidelines:

• Make sure unit tests pass (nx affected --target=test)
  • Target a specific project with: nx run proj:test (i.e. nx run angular:test to target packages/angular)
  • Target a specific unit test file (i.e. packages/angular/src/utils/ast-command-line-utils.spec.ts) with npx jest angular/src/utils/ast-utils or npx jest packages/angular/src/utils/ast-utils
  • For more options on running tests - check npx jest --help or visit jestjs.io
  • Debug with node --inspect-brk ./node_modules/jest/bin/jest.js build/packages/angular/src/utils/ast-utils.spec.js
• Make sure e2e tests pass (this can take a while, so you can always let CI check those) (nx affected --target=e2e)
  • Target a specific e2e test with nx e2e e2e-cypress
• Make sure you run nx format
• Update documentation with yarn documentation. For documentation, check for spelling and grammatical errors.
• Update your commit message to follow the guidelines below (use yarn commit to automate compliance)
  • yarn check-commit will check to make sure your commit messages are formatted correctly

Commit Message Guidelines

The commit message should follow the following format:

type(scope): subject
BLANK LINE
body

Type

The type must be one of the following:

• feat - New or improved behavior being introduced (e.g. Updating to new versions of React or Jest which bring in new features)
• fix - Fixes the current unexpected behavior to match expected behavior (e.g. Fixing the library generator to create the proper named project)
• cleanup - Code Style changes that have little to no effect on the user (e.g. Refactoring some functions into a different file)
• docs - Changes to the documentation (e.g. Adding more details into the getting started guide)
• chore - Changes that have absolutely no effect on users (e.g. Updating the version of Nx used to build the repo)

Scope

The scope must be one of the following:

• angular - anything Angular specific
• bundling - anything bundling specific (e.g. rollup, webpack, etc.)
• core - anything Nx core specific
• detox - anything Detox specific
• devkit - devkit-related changes
• graph - anything graph app specific
• expo - anything Expo specific
• express - anything Express specific
• js - anything related to @nrwl/js package or general js/ts support
• linter - anything Linter specific
• nest - anything Nest specific
• nextjs - anything Next specific
• node - anything Node specific
• nx-cloud - anything NxCloud specific
• nx-plugin - anything Nx Plugin specific
• nx-dev - anything related to docs infrastructure
• react - anything React specific
• react-native - anything React Native specific
• repo - anything related to managing the Nx repo itself
• storybook - anything Storybook specific
• testing - anything testing specific (e.g., Jest or Cypress)
• vite - anything Vite specific
• web - anything Web specific
• webpack - anything Webpack specific
• misc - misc stuff

Subject and Body

The subject must contain a description of the change, and the body of the message contains any additional details to provide more context about the change.

Including the issue number that the PR relates to also helps with tracking.

Example

feat(angular): add an option to generate lazy-loadable modules

`nx generate lib mylib --lazy` provisions the mylib project in tslint.json

Closes #157

Commitizen

To simplify and automate the process of committing with this format, Nx is a Commitizen friendly repository, just do git add and execute yarn commit.