pnpm/CONTRIBUTING.md

Contributing

Table of contents

• Setting Up the Environment
  • JavaScript and TypeScript CLI
  • Rust toolchain and git hooks
• Working with Git Worktrees
• Running Tests
• Submitting a Pull Request (PR)
  • After your pull request is merged
• Coding Style Guidelines
• Commit Message Guidelines
  • Commit Message Format
    • Revert
    • Type
    • Scope
    • Subject
    • Body
    • Footer

Setting Up the Environment

The repository holds two implementations of the same package manager: the TypeScript pnpm CLI and the Rust pacquet port (plus the Rust pnpr registry server). Most contributions touch Rust, but the two stacks share one workspace, so set up both.

JavaScript and TypeScript CLI

1. Run pnpm install in the root of the repository to install all dependencies.
2. Run pnpm add ./pnpm/dev -g to make pnpm from the repository available in the command line via the pd command.
3. Run pnpm run compile to create an initial build of pnpm from the source in the repository.
4. Now you can change any source code file and run pd [command] [flags] to run pnpm directly from the source code by compiling all the files without typechecking in memory.
5. Alternatively, for recompiling all the projects with typechecking after your changes, again run pnpm run compile in the root of the repository.
6. In order to run all the tests in the repository, run pnpm run test-main. You may also run tests of specific projects by running pnpm test inside a project's directory or using pnpm --filter <project name> test.

Some of the e2e tests run node-gyp, so you might need to install some build-essentials on your system for those tests to pass. On Fedora, install these:

sudo dnf install make automake gcc gcc-c++ kernel-devel

Rust toolchain and git hooks

Rust is now the primary language in this repository, so most contributions need a working Rust toolchain and the Rust developer tools. The Rust workspace (Cargo.toml, rust-toolchain.toml, justfile) lives at the repository root; run cargo and just from there.

1. Install rustup. You do not need to select a toolchain by hand. rust-toolchain.toml pins the version the project builds with, and rustup installs it, together with rustfmt and clippy from the pinned default profile, the first time you run cargo inside the repository.

2. Install just (the task runner) and cargo-binstall, then install the task tools from the repository root:

   just init
   

   just init installs cargo-nextest, cargo-watch, cargo-insta, typos-cli, taplo-cli, wasm-pack, and cargo-llvm-cov.

3. Install the dylint tools, which just init does not cover, from source:

   cargo install cargo-dylint dylint-link
   

   Install these from source rather than with cargo binstall. The prebuilt cargo-dylint binaries reference the dylint_driver crate at the path where they were built, so building the per-toolchain driver fails locally with an error that points at a nonexistent .../dylint/driver directory. A cargo install build resolves the driver against your local cargo registry and works.

Make sure ~/.cargo/bin is on your PATH, ahead of any system-wide Rust in /usr/bin. rustup's installer adds this entry through ~/.cargo/env; ensure your shell sources it. This matters for the git hooks. The pnpm install step above wires up husky, and its pre-push hook runs the Rust checks in pnpm/scripts/pre-push-rust.sh (format, doc, dylint, typos) alongside the TypeScript compile and lint. That script locates cargo, rustup, taplo, typos, and cargo-dylint through PATH, and it skips a check when the tool is not found rather than failing. A push that appears to pass locally with the tools off PATH has silently skipped the format, doc, and dylint checks, so those problems surface only in CI.

For the full Rust development workflow (checks, tests, benchmarks, and the code style guide), see pnpm/CONTRIBUTING.md.

Working with Git Worktrees

Worktrees let you check out multiple branches simultaneously in separate directories, which is useful for working on several issues in parallel without stashing or switching branches. This is particularly powerful when running multiple AI coding agents (e.g. Claude Code) at the same time — each agent gets its own isolated worktree, so they can work concurrently without interfering with each other.

Setting up a bare-repo layout with worktrees

Cloning as a bare repository lets all worktrees live as children of a single top-level directory. That avoids the "one privileged main clone + siblings" asymmetry: every branch is just a directory next to the others, and there is no working tree attached to the bare repo itself. This is especially handy when you expect to keep many worktrees around long-term — for example, one per in-flight PR, or one per parallel AI agent.

The resulting layout looks like this:

~/src/pnpm/pnpm/          # the bare repo (contains HEAD, config, objects/, refs/, worktrees/)
├── main/                 # worktree for main
├── v10/                  # worktree for the v10 release branch
├── fix-1234/             # worktree for branch fix/1234
└── feat-my-feature/      # worktree for branch feat/my-feature

One-time setup:

1. Clone as a bare repository at the directory that will hold all worktrees:

   git clone --bare https://github.com/pnpm/pnpm.git ~/src/pnpm/pnpm
   cd ~/src/pnpm/pnpm
   

2. Point Husky at a path that exists inside every worktree (not inside the bare repo's gitdir), so commit and push hooks run when you commit from any worktree:

   git config core.hooksPath .husky/_
   

3. Create the first worktree for main and install dependencies:

   git worktree add main main
   cd main
   pnpm install
   

4. Install @zkochan/git-wt globally. It provides a git-wt binary that creates a worktree for a branch or PR and prints its path, plus a wt shell function that cds into the new worktree in one step:

   pnpm add -g @zkochan/git-wt
   

   Then wire the wt function into your shell config so it's available in every future session. Pick the snippet for your shell — it appends to the right rc file and activates wt in the current session too:

   fish:

   echo 'git-wt init fish | source' >> ~/.config/fish/config.fish
   git-wt init fish | source
   

   bash:

   echo 'eval "$(git-wt init bash)"' >> ~/.bashrc
   eval "$(git-wt init bash)"
   

   zsh:

   echo 'eval "$(git-wt init zsh)"' >> ~/.zshrc
   eval "$(git-wt init zsh)"
   

5. (Optional) If you push to your own fork as well as origin, add it once in the bare repo:

   git -C ~/src/pnpm/pnpm remote add <your-username> git@github.com:<your-username>/pnpm.git
   

Usage

From inside any existing worktree:

# Create a worktree for an existing branch and switch to it
wt fix/4444

# Create a worktree for a new branch (branched from main) and switch to it
wt feat/my-feature

# Create a worktree for a GitHub PR (works for forks too) and switch to it
wt 10000

wt creates the new worktree next to the current one — in the bare-repo layout that means it lands as a sibling of main/, inside the bare repo directory. Branch names with slashes get their slashes replaced with dashes in the directory name (so feat/my-feature becomes feat-my-feature/).

Passing a number is interpreted as a PR number. The PR is fetched via git fetch origin pull/<number>/head into a local branch named pr-<number>, so it works for both same-repo branches and forks.

For PR worktrees, git wt <pr-number> will additionally launch an agent review of the PR via the tracked hook at .git-wt/pr-hook. The hook defaults to Claude Code, but you can pass another agent CLI name after the PR number, for example git wt 10000 codex. The hook silently no-ops if the requested CLI isn't on your PATH, so contributors who don't use an agent aren't affected. Requires a version of @zkochan/git-wt with per-repo hook lookup.

If you only need the worktree path (e.g. to open it in an editor) without switching directories, invoke git-wt directly — it's also exposed as a native git subcommand:

git wt feat/my-feature
git wt 10000

Running Tests

You can run the tests of the project that you modified by going to the project's directory and running:

pnpm test

Alternatively, you can run it from anywhere by specifying the name of the project using the --filter option:

pnpm --filter core test

If you want to pass options to Jest, use the pnpm run test command and append any needed options. For instance, if you want to run a single test in a single file, run:

pnpm --filter core run test test/lockfile.ts -t "lockfile has dev deps even when installing for prod only"

Submitting a Pull Request (PR)

Before you submit your Pull Request (PR) consider the following guidelines:

• Search GitHub for an open or closed PR that relates to your submission. You don't want to duplicate effort.

• Make your changes in a new git branch:

  git checkout -b my-fix-branch main
  

• Create your patch, following code style guidelines, and including appropriate test cases.

• Run pnpm changeset in the root of the repository and describe your changes. The resulting files should be committed as they will be used during release. Write the description for pnpm users and keep it concise — it becomes a release note. Implementation rationale belongs in the commit message, not the changeset.

• Run the full test suite and ensure that all tests pass.

• Commit your changes using a descriptive commit message that follows our commit message conventions. Adherence to these conventions is necessary because release notes are automatically generated from these messages.

  git commit -a
  

  Note: the optional commit -a command line option will automatically "add" and "rm" edited files.

• Push your branch to GitHub:

  git push origin my-fix-branch
  

• In GitHub, send a pull request to pnpm:main.

• If we suggest changes then:

  • Make the required updates.

  • Re-run the test suites to ensure tests are still passing.

  • Rebase your branch and force push to your GitHub repository (this will update your Pull Request):

    git rebase main -i
    git push -f
    

That's it! Thank you for your contribution!

After your pull request is merged

After your pull request is merged, you can safely delete your branch and pull the changes from the main (upstream) repository:

• Delete the remote branch on GitHub either through the GitHub web UI or your local shell as follows:

  git push origin --delete my-fix-branch
  

• Check out the main branch:

  git checkout main -f
  

• Delete the local branch:

  git branch -D my-fix-branch
  

• Update your main with the latest upstream version:

  git pull --ff upstream main
  

Coding Style Guidelines

Use the Standard Style.

Commit Message Guidelines

We have very precise rules over how our git commit messages can be formatted. This leads to more readable messages that are easy to follow when looking through the project history.

Commit Message Format

Each commit message consists of a header, a body and a footer. The header has a special format that includes a type, a scope and a subject:

<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>

The header is mandatory and the scope of the header is optional.

Any line of the commit message cannot be longer than 100 characters! This allows the message to be easier to read on GitHub as well as in various git tools.

Revert

If the commit reverts a previous commit, it should begin with revert:, followed by the header of the reverted commit. In the body it should say: This reverts commit <hash>., where the hash is the SHA of the commit being reverted.

Type

Must be one of the following:

• feat: A new feature
• fix: A bug fix
• docs: Documentation only changes
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• refactor: A code change that neither fixes a bug nor adds a feature
• perf: A code change that improves performance
• test: Adding missing tests
• chore: Changes to the build process or auxiliary tools and libraries such as documentation generation

Scope

The scope could be anything specifying place of the commit change. For example plugin-example, render-md, etc.

Subject

The subject contains succinct description of the change:

• use the imperative, present tense: "change" not "changed" nor "changes"
• don't capitalize first letter
• no dot (.) at the end

Body

Just as in the subject, use the imperative, present tense: "change" not "changed" nor "changes". The body should include the motivation for the change and contrast this with previous behavior.

Footer

The footer should contain any information about Breaking Changes and is also the place to reference GitHub issues that this commit Closes.

Breaking Changes should start with the word BREAKING CHANGE: with a space or two newlines. The rest of the commit message is then used for this.