Use a GitHub Action oficial setup-bun para instalar o bun no seu runner do GitHub Actions.

name: my-workflow
jobs:
  my-job:
    name: my-job
    runs-on: ubuntu-latest
    steps:
      # ...
      - uses: actions/checkout@v4
      - uses: oven-sh/setup-bun@v2

      # executar qualquer comando `bun` ou `bunx`
      - run: bun install
      - run: bun index.ts
      - run: bun run build

---

Para especificar uma versão do Bun para instalar:

name: my-workflow
jobs:
  my-job:
    name: my-job
    runs-on: ubuntu-latest
    steps:
      # ...
      - uses: oven-sh/setup-bun@v2
        with: 
          bun-version: 1.3.3 # ou "latest", "canary", <sha> 

---

Consulte o README.md para documentação completa da GitHub Action setup-bun.