This action will build Rust-based WASM plugins for distribution, primarily for moon and proto. It achieves this by:

• Finding all buildable packages using cargo metadata.
• Builds all packages using cargo build --release --target wasm32-wasip1.
• Optimizes all .wasm files with wasm-opt and wasm-strip.
• Generates .sha256 checksum files for all .wasm files.
• Moves built files to a builds directory.
• Extract changelog information for a release.
• Optionally publish to ghcr.io as an OCI artifact.

Here's an example GitHub action workflow that builds applicable packages and creates a GitHub release when a tag is pushed.

name: Release

permissions:
  contents: write

on:
  push:
    tags:
      - 'v[0-9]+*'
  pull_request:

jobs:
  build:
    name: Build
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
      - uses: moonrepo/setup-rust@v1
        with:
          cache: false
          targets: wasm32-wasi
      - id: build
        uses: moonrepo/build-wasm-plugin@v0
      - if: ${{ github.event_name == 'push' && github.ref_type == 'tag' }}
        uses: ncipollo/release-action@v1
        with:
          artifacts: builds/*
          artifactErrorsFailBuild: true
          body: ${{ steps.build.outputs.changelog-entry }}
          prerelease: ${{ steps.build.outputs.prerelease == 'true' }}
          skipIfReleaseExists: true

This plugin can also publish the built WASM plugin to ghcr.io as an OCI artifact. To do so, apply the following changes to your workflow:

1. Update permissions to the following:

permissions:
  contents: write
  packages: write
  attestations: write
  id-token: write

2. Enable the publish input and pass your GitHub token:

- id: build
  uses: moonrepo/build-wasm-plugin@v0
  with:
    publish: true
  env:
    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

By default this will use the repository owner (org/user) as the OCI namespace. If you want to customize this, configure the namespace input.

Packages to be built and published must have the following configuration in their Cargo.toml:

• The lib.crate-type setting should be set to cdylib.

[package]
name = "example_plugin"
version = "1.2.3"
edition = "2021"
license = "MIT"

[lib]
crate-type = ['cdylib']

Furthermore, this action will inherit the profile.release.opt-level setting from the current package (or workspace root) Cargo.toml. This setting will be passed to wasm-opt. We suggest s for file size, or z for runtime speed.

[profile.release]
codegen-units = 1
debug = false
lto = true
opt-level = "s"
panic = "abort"