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Setting Up Your Local Dev Environment

This page outlines how to get set up to contribute to Gatsby core and its ecosystem. For instructions on working with docs, visit the docs contributions page.

Gatsby uses a “monorepo” pattern to manage its many dependencies and relies on Lerna and Yarn to configure the repository for both active development and documentation infrastructure changes.

Using Yarn

Yarn is a package manager for your code, similar to npm. While npm is used to develop Gatsby sites with the CLI, contributing to the Gatsby repo requires Yarn for the following reason: we use Yarn’s workspaces feature that comes really handy for monorepos. It allows us to install dependencies from multiple package.json files in sub-folders, enabling a faster and lighter installation process.

Gatsby repo instructions

Install Node and Yarn

  • Ensure you have the latest LTS version of Node installed (>= 10.16.0). node --version
  • Install the Yarn package manager.
  • Ensure you have the latest version of Yarn installed (>= 1.0.2). yarn --version

Fork, clone, and branch the repository

  • Fork the official gatsbyjs/gatsby repository.

  • Clone your fork: git clone --depth=1 https://github.com/<your-username>/gatsby.git

  • Set up repo and install dependencies: yarn run bootstrap

  • Make sure tests are passing for you: yarn test

  • Create a topic branch: git checkout -b topics/new-feature-name

  • Run yarn run watch from the root of the repo to watch for changes to packages’ source code and compile these changes on-the-fly as you work.

    • Note that the watch command can be resource intensive. To limit it to the packages you’re working on, add a scope flag, like yarn run watch --scope={gatsby,gatsby-cli}.
    • To watch just one package, run yarn run watch --scope=gatsby.

Docs only changes

Gatsby functional changes

  • Install gatsby-cli:

    • Make sure you have the Gatsby CLI installed with gatsby -v,
    • if not, install globally: yarn global add gatsby-cli
  • Install gatsby-dev-cli:

    • Make sure you have the Gatsby Dev CLI installed with gatsby-dev -v
    • if not, install globally: yarn global add gatsby-dev-cli
  • Run yarn install in each of the sites you’re testing.

  • For each of your Gatsby test sites, run the gatsby-dev command inside the test site’s directory to copy the built files from your cloned copy of Gatsby. It’ll watch for your changes to Gatsby packages and copy them into the site. For more detailed instructions see the gatsby-dev-cli README and check out the gatsby-dev-cli demo video.

    • Note: if you plan to modify packages that are exported from gatsby directly, you need to either add those manually to your test sites so that they are listed in package.json (e.g. yarn add gatsby-link), or specify them explicitly with gatsby-dev --packages gatsby-link).
  • If you’ve recently run gatsby-dev your node_modules will be out of sync with current published packages. In order to undo this, you can remove the node_modules directory or run:

Add tests

  • Add tests and code for your changes.

  • Once you’re done, make sure all tests still pass: yarn test.

    • To run tests for a single package you can run: yarn jest <package-name>.
    • To run a single test file you can run: yarn jest <file-path>.

If you’re adding e2e tests and want to run them against local changes:

  • In the root of the monorepo, run yarn lerna run build --scope=<package-name> where package-name is the directory containing the changes you’re testing.
  • Run gatsby-dev inside your specific e2e test directory, for example e2e-tests/themes/development-runtime.
  • While the previous step is running, open a new terminal window and run yarn test in that same e2e test directory.

Troubleshooting

At any point during the contributing process the Gatsby team would love to help! For help with a specific problem you can open an issue on GitHub. Or drop in to our Discord server for general community discussion and support.

  • When you went through the initial setup some time ago and now want to contribute something new, you should make sure to sync your fork with the latest changes from the primary branch on gatsbyjs/gatsby. Otherwise, you might run into issues where files are not found as they were renamed, moved, or deleted.
  • After syncing your fork, run yarn run bootstrap to compile all packages. When files or tests depend on the build output (files in /dist directories) they might fail otherwise.
  • Make sure to run yarn run watch on the packages’ source code you’re changing.

Additional information

Commits and pull requests

Sync your fork

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