Add a test

.github/workflows/nix.yml

@@ -0,0 +1,33 @@
+name: nix
+
+on: [push, pull_request]
+
+permissions: {}
+
+jobs:
+  nix:
+    if: github.repository == 'Swatinem/rust-cache'
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+
+    name: Test Nix on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
+        with:
+          persist-credentials: false
+
+      - uses: cachix/install-nix-action@7e5978947b7efba56e96c43fd785691980aca924 # v31.8.4
+
+      - uses: ./
+        with:
+          workspaces: tests
+          cmd-format: nix develop tests -c {0}
+
+      - run: |
+          nix develop -c cargo check --color always
+          nix develop -c cargo test --color always
+        working-directory: tests

tests/flake.nix

@@ -0,0 +1,23 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = inputs @ { self, nixpkgs, flake-utils, rust-overlay, ... }:
+    flake-utils.lib.eachDefaultSystem (
+      system: let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs { inherit system overlays; };
+      in {
+        devShells.default = with pkgs; mkShell {
+          buildInputs = [ rust-bin.stable.latest.minimal ];
+        };
+      }
+    );
+}
+