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This topic includes a description of common development workflows for the Wing project.

How to prepare for take-off? ๐Ÿคโ€‹


You can open up this repo by clicking the badge below. It is recommended to select a 4-core minimum machine. Open in GitHub Codespaces


For windows we recommend to set the tools up within WSL as some of the scripts don't support windows and expect unix tooling.

Some Guides:

Here is a list of minimal tools you should install to build the Wing repo in your development environment:

  • Node.js v20 and PNPM v8
    • We recommend volta to manage node tools
  • Rust
    • We recommend using rustup to manage your Rust installation if Rust is not already installed. Be careful of conflicting Rust installations (homebrew rust and rustup)
    • Only needed for integration tests - make sure to do the setup part to create credentials
  • Terraform CLI
    • Only needed for integration tests
  • Docker
    • Needed to build the grammar as WASM for the web-based playground and to run unit tests


git clone
cd wing
pnpm install
Turbo Commands

Turbo commands in this document are structured as

pnpm turbo <task>
# or
pnpm turbo <task> --filter=<project> -- <args>
  • pnpm can be omitted if Turbo is installed globally
  • --filter=<project> may be used to filter to a specific project (and it's dependencies)
  • Running turbo <task> inside of a project directory will automatically filter to that project
  • We use Turbo caching to speed up builds. If you want to force a rebuild, use --force.

Full buildโ€‹

If you wish to perform a full build (similar to the one CI is running), just run this from the root:

pnpm build

It will compile, lint, test and package all modules.


When testing your changes to Wing, locally it may be helpful to be able to easily invoke your local version of the Wing CLI. In which case adding a shell alias may be helpful for instance on Linux and Mac you could add:

alias mywing=/<PATH_TO_WING_REPO>/apps/wing/bin/wing to your shell's rc file.

The pnpm wing command can be executed from the root of the repository in order to build and run the compiler, SDK (standard library) and the Wing CLI. Turbo is configured to make sure only the changed components are built every time.

To get full diagnostics, use these exports:

export NODE_OPTIONS=--stack-trace-limit=100
export RUST_BACKTRACE=full

Or if you just want to compile your changes and run a local version of the Wing CLI:

pnpm compile --filter=winglang

Now, you can edit a source file anywhere across the stack and run the compiler with arguments. For example:

pnpm wing -- test examples/tests/valid/captures.test.w

This command runs the full Wing CLI with the given arguments. Turbo will ensure the CLI build is updated.

How is the repository structured?โ€‹

The Wing repository is structured as a monorepo, which means that it contains multiple packages. Packages that are primarily meant to be run by users are in the apps directory, while packages that are primarily meant to be consumed as libraries are in the libs directory. Some packages are written in Rust, while others are written in TypeScript. Each has a README explaining what it does and how to use it. (If you see one missing, please open an issue and let us know!)

The Wing monorepo uses Turbo to run commands across all code packages in the libs and apps folders. This means it includes packages that form the entire toolchain (compiler, standard library, IDE extension, etc), and the build and release bind them all together.

Turbo will be installed alongside the rest of the project's dependencies after you run pnpm install from the root directory, and can be accessed with pnpm turbo if Turbo is not installed globally.


The first time you run pnpm install it may take extra time to install the wasi-sdk for you. This is needed to compile Wing for WASM.

If you wish to install it manually, you may do so by running scripts/

๐Ÿงช How do I run tests?โ€‹

End-to-end tests are hosted under tools/hangar. To get started, first ensure you can build wing.

To run the tests (and update snapshots), run the following command from anywhere in the monorepo:

pnpm turbo wing:e2e

(This is a helpful shortcut for pnpm turbo test --filter=hangar)

Test Meta-Commentsโ€‹

In your wing files in examples/tests/valid, you can add a specially formatted comment to add additional information for hangar. Inside this comment, a yaml block will be read and used for several purposes.


- win32
- darwin

Currently, the only supported meta-comment for regular tests is skipPlatforms. This will skip the test on the given platforms when when running on CI. The current supported platforms are win32, darwin, and linux. This is useful if, for example, the test requires docker. In our CI only linux supports docker.


Benchmark files are located in examples/tests/valid/benchmarks. To run the benchmarks, run the following command from anywhere in the monorepo:

pnpm turbo wing:bench

(This is a helpful shortcut for pnpm turbo bench --filter=hangar)

In CI, if these benchmarks regress too far from the current main branch, the build will fail.

How do I work only on the compiler?โ€‹

The following command runs the rust tests in wingc, including verification that valid tests compile, invalid tests do not compile, and none of them panic.

It will also make sure to update any snapshots.

pnpm turbo test --filter=wingc

The following command runs wingc on a file. This performs all the compilation steps. Run from the root.

pnpm wing -- compile <path to a .w file (full path, or relative to the location of the apps/wing folder)>

You can find the compilation artifacts in the apps/wing/target folder.

To check that your code passes all the lints, run:

pnpm turbo lint --filter=wingc

Optional VSCode extensions for working on the compilerโ€‹

You can show clippy errors in your IDE by installing the rust-analyzer extension and setting the option "Rust-analyzer โ€บ Check: Command" to "clippy" instead of "check".

The insta extension allows you to view snapshots in the tests files.

How do I debug the Wing compiler on VSCode?โ€‹

To debug the Rust compiler on VSCode, first you need to install the CodeLLDB extension.
Next, you can use the Debug Wing Compiler launch configuration available on our launch.json.

Open the .w file you wish to debug compilation for (e.g. ${workspaceFolder}/examples/tests/valid/hello.w) and hit F5 to start debugging.

How do I make changes to the Wing grammar?โ€‹

After making changes to grammar.js, run:

pnpm turbo compile --filter=tree-sitter-wing

To run the grammar tests (that are located in the test folder):

pnpm turbo test --filter=tree-sitter-wing

To use the wasm grammar to run a web-based playground where you can explore the AST and test out highlight queries, run:

pnpm turbo playground --filter=tree-sitter-wing

๐Ÿ”จ How do I build the VSCode extension?โ€‹

The VSCode extension is located in apps/vscode-wing. Most of the "logic" is in the language server, which is located in the Wing CLI at apps/wing/src/commands/lsp.ts.

To compile the extension (also creates an installable .vsix file):

pnpm turbo compile --filter=vscode-wing

To run a new isolated VSCode instance with the extension installed:

pnpm turbo dev --filter=vscode-wing

To modify the package.json, make sure to edit .projenrc.ts and rebuild.

Tip: if you want to print debug messages in your code while developing, you should use Rust's dbg! macro, instead of print! or println!.

๐Ÿงน How do I lint my code?โ€‹

To lint Rust code, you can run the lint target on the wingc or wingii projects:

pnpm turbo lint --filter=wingc

It's also possible to lint by running cargo clippy directly.

Lastly you can show linting errors in your IDE by enabling the following setting in the rust-analyzer extension:

// in your VS Code settings
"rust-analyzer.check.command": "clippy",

๐Ÿ How do I add a quickstart template to the wing CLI?โ€‹

Adding a new template is straightforward!

Each template is represented by a folder located at project-templates, containing all of the files that template should be initialized with.

Create a new folder with the template name, and insert any code files that are needed to run it. Unit tests ran with pnpm turbo test (or in GitHub Actions once you make a pull request) will automatically validate that the template is valid.