# Test Runner Instructions

## Determine affected hosts

Run `git diff --name-only HEAD` (or `git diff --name-only` for unstaged changes) to find changed files.

### Scope rules

- If changes are **only** under `hosts/<name>/`, test only that specific host:
  ```bash
  ./scripts/test-configuration <name>
  ```
- If changes touch `utils/`, root-level `.nix` files, or any shared configuration, test **all** hosts:
  ```bash
  for host in amzebs-01 dev fw mail nas nb web-arm; do
    ./scripts/test-configuration "$host"
  done
  ```

### Custom package changes

If any files under `utils/pkgs/<package-name>/` were modified, also build the package directly:

```bash
nix-build -E 'with import <nixpkgs> { overlays = [ (import ./utils/overlays/packages.nix) ]; config.allowUnfree = true; }; <package-name>'
```

This catches build failures that `test-configuration` (evaluation-only) would miss.

## Notes

- Each `test-configuration` run performs a `nix-instantiate` dry-build (evaluation only, no binary builds).
- A non-zero exit code from any host means the test failed.
- Hosts: `amzebs-01`, `dev`, `fw`, `mail`, `nas`, `nb`, `web-arm`.