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moon v1.13 - Toolchain now uses WASM plugins

· 3 min read
Miles Johnson
Founder, developer

This is a light release that focused primarily on upgrading to the WASM based proto implementation.

proto upgrade and WASM plugins

Over the last few months, we've made immense strides on proto, our multi-language toolchain. For those of you unaware, moon's toolchain is built on top of proto, and we accomplish this by utilizing the same Rust code between both tools.

However, moon has been locked to proto v0.12, which was a purely Rust based implementation. With the release of proto v0.13 and onward, proto has moved to a WASM based plugin architecture (with the core still in Rust), which allows us to support more languages, and enables developers to write plugins in non-Rust languages.

And since our WASM plugins have stabilized by proto v0.16, we felt it was time to finally upgrade moon's implementation to the latest and greatest. So what does this mean exactly? A few things:

  • If you're using moon's toolchain (like node), we will now download the Node.js WASM plugins in the background (to ~/.proto/plugins).
  • These plugins are in charge of downloading and installing the Node.js, npm, pnpm, or yarn version specified in your toolchain configuration.
  • The entire plugin flow is now logged to the console, so you can see what's happening behind the scenes.
  • In the future (most likely moon v2), our platform and language integration will also be powered by WASM plugins. This enables you to build your own custom plugins!

This entire process should be transparent to all users, and you should not notice any changes. However, in case this upgrade causes issues, we wanted to isolate it from other changes, hence the light release!

Allow tasks to fail

"Allow tasks to fail?" You ask yourself. "Doesn't that defeat the point of a task runner?" You question further. "You're not wrong!" We reply. These questions assume a perfect repository state, where all tasks either pass or fail, and there's no middle ground. In reality, very rarely is that true, and we want to support those stuck in the middle, such as:

  • In a heavy migration and it's known that a task is currently broken.
  • The task is flaky but you've been unable to find the root cause.
  • Upstream dependencies have published a backwards incompatible change, and you're waiting on a fix.
  • And of course, in the middle of adopting moon!

For situations where a task consistently or sometimes fails, but you don't want it to fail the entire pipeline (especially in CI), you can enable the new allowFailure task option.

command: 'tsc --build'
allowFailure: true

When enabled, failing tasks will no longer bail moon run early, nor will it exit moon ci with a non-zero exit code. However, we still built guard rails around this feature, as we don't want to encourage bad practices, and one of these guard rails is that tasks that enable allowFailure cannot be depended on by other tasks, as we cannot guarantee that it's side-effect free.

Other changes

View the official release for a full list of changes.

  • Added colors to command line --help menus.
  • Updated runner.archivableTargets to support tag scoped targets.
  • Updated moon query tasks --affected to filter based on affected task, instead of affected project.