Build wasm workflow (astral-sh/ruff)

The Build wasm workflow from astral-sh/ruff, explained and optimized by Latchkey.

CI health: A - excellent

Point runs-on at Latchkey and get job timeouts, self-healing for flaky steps, and up to 58% lower cost, applied automatically.

Grade your own workflow free or run it on Latchkey →

Source: astral-sh/ruff.github/workflows/build-wasm.ymlLicense MITView source

What it does

This is the Build wasm workflow from the astral-sh/ruff repository, a real project running GitHub Actions. It is shown here with attribution under its MIT license.

Below, Latchkey shows a faster, safer version produced by its optimization engine.

The workflow

workflow (.yml)

# Build ruff_wasm for npm.
#
# Assumed to run as a subworkflow of .github/workflows/release.yml; specifically, as a local
# artifacts job within `cargo-dist`.
name: "Build wasm"

on:
  workflow_call:
    inputs:
      plan:
        required: true
        type: string
  pull_request:
    paths:
      - .github/workflows/build-wasm.yml

concurrency:
  group: build-wasm-${{ github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

permissions: {}

env:
  CARGO_INCREMENTAL: 0
  CARGO_NET_RETRY: 10
  CARGO_TERM_COLOR: always
  RUSTUP_MAX_RETRIES: 10

jobs:
  build:
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
    runs-on: ubuntu-latest
    strategy:
      matrix:
        target: [web, bundler, nodejs]
      fail-fast: false
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
        with:
          version: v0.13.1
      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
      - name: "Run wasm-pack build"
        run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
      - name: "Rename generated package"
        run: | # Replace the package name w/ jq
          jq '.name="@astral-sh/ruff-wasm-${{ matrix.target }}"' crates/ruff_wasm/pkg/package.json > /tmp/package.json
          mv /tmp/package.json crates/ruff_wasm/pkg
      - run: cp LICENSE crates/ruff_wasm/pkg # wasm-pack does not put the LICENSE file in the pkg
      - name: "Upload wasm artifact"
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          # Avoid prefixing the name with `artifacts-` here to exclude it from the GitHub release.
          name: wasm-npm-${{ matrix.target }}
          path: crates/ruff_wasm/pkg

The same workflow, on Latchkey

Removes redundant runs and caps runaway jobs. Added and changed lines are highlighted.

# Build ruff_wasm for npm.
#
# Assumed to run as a subworkflow of .github/workflows/release.yml; specifically, as a local
# artifacts job within `cargo-dist`.
name: "Build wasm"
 
on:
  workflow_call:
    inputs:
      plan:
        required: true
        type: string
  pull_request:
    paths:
      - .github/workflows/build-wasm.yml
 
concurrency:
  group: build-wasm-${{ github.ref }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
 
permissions: {}
 
env:
  CARGO_INCREMENTAL: 0
  CARGO_NET_RETRY: 10
  CARGO_TERM_COLOR: always
  RUSTUP_MAX_RETRIES: 10
 
jobs:
  build:
    timeout-minutes: 30
    if: ${{ !contains(github.event.pull_request.labels.*.name, 'no-build') }}
    runs-on: latchkey-small
    strategy:
      matrix:
        target: [web, bundler, nodejs]
      fail-fast: false
    steps:
      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
        with:
          persist-credentials: false
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
      - uses: jetli/wasm-pack-action@0d096b08b4e5a7de8c28de67e11e945404e9eefa # v0.4.0
        with:
          version: v0.13.1
      - uses: jetli/wasm-bindgen-action@20b33e20595891ab1a0ed73145d8a21fc96e7c29 # v0.2.0
      - name: "Run wasm-pack build"
        run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
      - name: "Rename generated package"
        run: | # Replace the package name w/ jq
          jq '.name="@astral-sh/ruff-wasm-${{ matrix.target }}"' crates/ruff_wasm/pkg/package.json > /tmp/package.json
          mv /tmp/package.json crates/ruff_wasm/pkg
      - run: cp LICENSE crates/ruff_wasm/pkg # wasm-pack does not put the LICENSE file in the pkg
      - name: "Upload wasm artifact"
        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
        with:
          # Avoid prefixing the name with `artifacts-` here to exclude it from the GitHub release.
          name: wasm-npm-${{ matrix.target }}
          path: crates/ruff_wasm/pkg

What changed

Run on Latchkey managed runners with one line (runs-on), which apply the fixes below automatically and self-heal transient failures. This example uses latchkey-small; pick the runner size that fits the job.
Add a job timeout so a hung step cannot burn hours of runner time.

This workflow runs 1 job (3 with the matrix expanded) per trigger. On Latchkey the same minutes cost up to 58% less than GitHub-hosted, with zero queue time.

Actions used in this workflow

actions/checkout actions/upload-artifact