environment.links: add test

nixos/tests/all-tests.nix

@@ -313,6 +313,7 @@ in {
   envoy = handleTest ./envoy.nix {};
   environmentAliases = callTest ./environment-aliases.nix {};
   environmentSkel = callTest ./environment-skel.nix {};
+  environmentLinks = callTest ./environment-links.nix {};
   ergo = handleTest ./ergo.nix {};
   ergochat = handleTest ./ergochat.nix {};
   eris-server = handleTest ./eris-server.nix {};

nixos/tests/environment-links.nix

@@ -0,0 +1,21 @@
+import ./make-test.nix ({ pkgs, ...} : {
+  name = "environment-links";
+  meta = with pkgs.stdenv.lib.maintainers; {
+    maintainers = [ mkg20001 ];
+  };
+
+  nodes = {
+    machine = { config, lib, pkgs, ... }: {
+      environment.links = {
+        "bin/bash".source = "${pkgs.bash}/bin/bash";
+      };
+    };
+  };
+
+  testScript = {nodes, ...}: ''
+    $machine->start();
+    $machine->waitForUnit("default.target");
+
+    $machine->succeed("/bin/bash -c true");
+  '';
+})