tests: prevent some unnecessary downloads

tests/modules/programs/firefox/deprecated-native-messenger.nix

@@ -11,15 +11,19 @@ with lib;
 
     nixpkgs.overlays = [
       (self: super: {
-        firefox-unwrapped = pkgs.runCommand "firefox-0" {
+        firefox-unwrapped = pkgs.runCommandLocal "firefox-0" {
           meta.description = "I pretend to be Firefox";
-          preferLocalBuild = true;
-          allowSubstitutes = false;
         } ''
           mkdir -p "$out/bin"
           touch "$out/bin/firefox"
           chmod 755 "$out/bin/firefox"
         '';
+
+        chrome-gnome-shell =
+          pkgs.runCommandLocal "dummy-chrome-gnome-shell" { } ''
+            mkdir -p $out/lib/mozilla/native-messaging-hosts
+            touch $out/lib/mozilla/native-messaging-hosts/dummy
+          '';
       })
     ];
 

tests/modules/programs/mpv/mpv-invalid-settings.nix

@@ -10,6 +10,18 @@
 
     nixpkgs.overlays = [
       (self: super: {
+        mpv-unwrapped = pkgs.runCommandLocal "mpv" {
+          version = "0";
+          passthru = {
+            lua.luaversion = "0";
+            luaEnv = "/dummy";
+            vapoursynthSupport = false;
+          };
+        } ''
+          mkdir -p $out/bin $out/Applications/mpv.app/Contents/MacOS
+          touch $out/bin/{,u}mpv $out/Applications/mpv.app/Contents/MacOS/mpv
+          chmod 755 $out/bin/{,u}mpv $out/Applications/mpv.app/Contents/MacOS/mpv
+        '';
         mpvDummy = pkgs.runCommandLocal "mpv" { } "mkdir $out";
         mpvScript =
           pkgs.runCommandLocal "mpvScript" { scriptName = "something"; }

tests/modules/programs/terminator/config-file.nix

@@ -8,6 +8,9 @@
       };
     };
 
+    nixpkgs.overlays =
+      [ (self: super: { terminator = pkgs.writeScriptBin "dummy" ""; }) ];
+
     nmt.script = ''
       assertFileContent home-files/.config/terminator/config ${
         pkgs.writeText "expected" ''

tests/modules/services/syncthing/tray-as-bool-triggers-warning.nix

@@ -6,6 +6,10 @@ with lib;
   config = {
     services.syncthing.tray = true;
 
+    nixpkgs.overlays = [
+      (self: super: { syncthingtray-minimal = pkgs.writeScriptBin "dummy" ""; })
+    ];
+
     test.asserts.warnings.expected = [
       "Specifying 'services.syncthing.tray' as a boolean is deprecated, set 'services.syncthing.tray.enable' instead. See https://github.com/nix-community/home-manager/pull/1257."
     ];

tests/modules/services/syncthing/tray.nix

@@ -6,6 +6,14 @@ with lib;
   config = {
     services.syncthing.tray.enable = true;
 
+    nixpkgs.overlays = [
+      (self: super: {
+        syncthingtray-minimal =
+          pkgs.runCommandLocal "syncthingtray" { pname = "syncthingtray"; }
+          "mkdir $out";
+      })
+    ];
+
     nmt.script = ''
       assertFileExists home-files/.config/systemd/user/syncthingtray.service
     '';