ci: add check step

.github/workflows/check.yml

@@ -0,0 +1,15 @@
+name: Check test suite
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+
+jobs:
+  check:
+    name: Check outputs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: DeterminateSystems/nix-installer-action@v15
+      - run: make check

Makefile

@@ -6,6 +6,10 @@ docs-serve:
 docs-build:
 	hugo -s docs/website
 
+.PHONY: check
+check:
+	{ command -v nix > /dev/null && nix flake check; } || { nix-build tests -A configs -A lib; }
+
 # Ideally, this should be done only in the remote CI environment with a certain
 # update cadence/rhythm.
 .PHONY: update