Start of tests

flake.nix

@@ -5,9 +5,24 @@
  */
 {
   description = "A wireguard network creation tool";
-  outputs = { self, ... }:
+  outputs = { self, nixpkgs, ... }:
+  let
+    forAllSystems = nixpkgs.lib.genAttrs [ "x86_64-linux" "aarch64-linux" ];
+  in
   {
     wnlib = import ./lib.nix;
     nixosModules.default = import ./wire.nix;
+    checks = forAllSystems (system: 
+      let
+        checkArgs = {
+          # reference to nixpkgs for the current system
+          pkgs = nixpkgs.legacyPackages.${system};
+          # this gives us a reference to our flake but also all flake inputs
+          inherit self;
+        };
+      in {
+      # import our test
+      null = import ./tests/null.nix checkArgs;
+    });
   };
 }

tests/lib.nix

@@ -0,0 +1,21 @@
+# tests/lib.nix
+# see https://blog.thalheim.io/2023/01/08/how-to-use-nixos-testing-framework-with-flakes/
+# The first argument to this function is the test module itself
+test:
+# These arguments are provided by `flake.nix` on import, see checkArgs
+{ pkgs, self}:
+let
+  inherit (pkgs) lib;
+  # this imports the nixos library that contains our testing framework
+  nixos-lib = import (pkgs.path + "/nixos/lib") {};
+in
+(nixos-lib.runTest {
+  hostPkgs = pkgs;
+  # This speeds up the evaluation by skipping evaluating documentation (optional)
+  defaults.documentation.enable = lib.mkDefault false;
+  # This makes `self` available in the NixOS configuration of our virtual machines.
+  # This is useful for referencing modules or packages from your own flake
+  # as well as importing from other flakes.
+  node.specialArgs = { inherit self; };
+  imports = [ test ];
+}).config.result

tests/null.nix

@@ -0,0 +1,22 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+(import ./lib.nix) {
+  name = "Null test, should always pass";
+  nodes = {
+    # `self` here is set by using specialArgs in `lib.nix`
+    node1 = { self, pkgs, ... }: {
+    };
+  };
+  # This is the test code that will check if our service is running correctly:
+  testScript = ''
+    start_all()
+    # wait for our service to start
+    node1.wait_for_unit("hello-world-server")
+    output = node1.succeed("echo Hello world")
+    # Check if our webserver returns the expected result
+    assert "Hello world" in output, f"'{output}' does not contain 'Hello world'"
+  '';
+}