Build software only once using Nix with the help of Cachix.

This action will configure Cachix and invoke nix-build.

Because you'd like for your CI to be fast. Let me explain.

Directory-based caching on a typical CI doesn't work well for Nix.

/nix/store is a global storage of everything Nix operates on. These are your sources, patches, tarballs, packages, configuration.

A directory-based cache requires downloading a whole store, including the irrelevant parts. cachix-action will only fetch what's needed by configuring a Nix binary cache.

When the build is done, cachix-action only has to upload the new store paths, rather than syncing the whole store.

Purging paths from a directory-based cache is not feasible because it'd have to be aware of all branches and their respective contents somehow.

1. Follow getting started to create your signing key
2. Backup the signing key in the process.

1. Click on Settings
2. Click on Secrets ([If missing, you need to sign up first for actions beta](https://github.com/features/actions))
3. Add your signing key value under name `CACHIX_SIGNING_KEY`.

name: "Test"
on:
  pull_request:
  push:
jobs:
  tests:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - uses: cachix/install-nix-action@v8
    - uses: cachix/cachix-action@v5
      with:
        name: mycache
        signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
        # Only needed for private caches
        authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
    - run: nix-build

See action.yml for all options.

Install the dependencies

$ yarn install

Build the typescript

$ yarn build

Run the tests ✔️

$ yarn test