nixosTests.ergochat: Test configuration reloading

nixos/tests/ergochat.nix

@@ -5,6 +5,7 @@ let
   ];
   server = "ergochat";
   ircPort = 6667;
+  altIrcPort = 16667;
   channel = "nixos-cat";
   iiDir = "/tmp/irc";
 in
@@ -22,6 +23,10 @@ in
           This one does.
         '';
       };
+
+      specialisation.new.configuration = {
+        services.ergochat.settings.server.listeners.":${toString altIrcPort}" = null;
+      };
     };
   }
   // lib.listToAttrs (
@@ -101,5 +106,10 @@ in
       # entry is executed by every client before advancing
       # to the next one.
     ''
-    + lib.concatStrings (reduce (lib.zipListsWith (cs: c: cs + c)) (map clientScript clients));
+    + lib.concatStrings (reduce (lib.zipListsWith (cs: c: cs + c)) (map clientScript clients))
+    # Test server config reloading
+    + ''
+      ${server}.succeed("/run/current-system/specialisation/new/bin/switch-to-configuration test")
+      ${server}.wait_for_open_port(${toString altIrcPort})
+    '';
 }