Testing

Tests in Marchyo are fast evaluation-based checks that verify NixOS configurations evaluate without errors. They don’t build any derivations, so they complete in under a minute.

Running tests

# Run all tests
nix flake check

# List available tests
nix eval .#checks.x86_64-linux --apply builtins.attrNames

There is no way to run a single test in isolation — nix flake check runs them all.

Test structure

tests/
  default.nix        # Entry point — auto-discovers tests/eval/ and merges the results
  lib.nix            # Shared helpers (assertTest, testNixOS, withTestUser, …)
  lib-tests.nix      # Library function unit tests
  eval/              # Per-feature module tests, auto-discovered (one file per feature)

Module tests

Verify that NixOS configurations evaluate without errors for various feature combinations:

Test	Description
eval-minimal	Minimal NixOS modules import
eval-desktop	Desktop feature flag
eval-development	Development feature flag
eval-all-features	All features enabled together
eval-themes	Theme configurations
eval-keyboard	Keyboard layouts and IME
eval-graphics-*	GPU configurations (Intel, AMD, NVIDIA, PRIME)

Library tests

Unit tests for lib functions using the assertTest helper.

Writing tests

Module evaluation test

Create (or extend) a file under tests/eval/ — e.g. tests/eval/my-feature.nix. Each file is a function that receives the shared helpers and returns an attrset of named tests; it is auto-discovered, so no registration is needed:

{ helpers, ... }:
let
  inherit (helpers) testNixOS withTestUser;
in
{
  eval-my-feature = testNixOS "my-feature" (withTestUser {
    marchyo.myFeature.enable = true;
  });
}

The testNixOS helper evaluates the NixOS config without building derivations. The withTestUser helper merges your config with a minimal bootable config (grub disabled, root filesystem, stateVersion).

Library test

Add to tests/lib-tests.nix, using the assertTest helper from tests/lib.nix (assertTest name assertion message — fails at evaluation time when the assertion is false):

test-my-function =
  let
    result = lib.myFunction "input";
  in
  assertTest "my-function" (result == "expected") "Expected myFunction to transform input";

CI pipeline

The GitHub Actions workflow (.github/workflows/validate.yml) runs four jobs:

1. Lint — nix fmt -- --ci plus a flake.lock / devenv.lock rev-parity check on a single Linux runner. Runs on every push and PR.
2. Check — nix flake check --accept-flake-config on x86_64-linux. Runs on every push and PR.
3. Check (aarch64-linux) — the same checks on an ARM runner. Runs only on pushes to main and manual dispatch.
4. Build — nix build .#nixosConfigurations.x86_64.config.system.build.toplevel. Runs only on pushes to main and manual dispatch, after lint and check succeed.

Lint and check run in parallel. Concurrency groups cancel superseded PR runs automatically. Builds use Cachix (jylhis cache).

A separate .github/workflows/site.yml workflow is a build-only gate for the website: changes touching site/** run bun run check and bun run build. Deployment happens outside GitHub Actions — Cloudflare Workers Builds deploys the site to marchyo.org on push to main.