add headless app for tests on CI

.github/workflows/e2e.yml

@@ -0,0 +1,28 @@
+name: "End-to-end tests"
+
+on:
+    push:
+        branches: ["main"]
+    pull_request:
+    workflow_dispatch:
+
+jobs:
+    e2e:
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v6
+              with:
+                  submodules: recursive
+
+            - name: Lix GHA Installer Action
+              uses: samueldr/lix-gha-installer-action@v2026-02-22
+              with:
+                  extra_nix_config: experimental-features = nix-command flakes flake-self-attrs
+
+            - name: Generate code
+              run: nix develop --command bash -c "flutter pub get && dart scripts/generate.dart && flutter pub run build_runner build"
+
+            - name: Run end-to-end tests
+              run: nix run .#e2e-headless

flake.lock

@@ -27,11 +27,11 @@
         "treefmt-nix": "treefmt-nix"
       },
       "locked": {
-        "lastModified": 1794004794,
-        "narHash": "sha256-fNmKraRLE963JuV3K4giays4KcOVCGpjvFuEG2E0hmE=",
+        "lastModified": 1794063651,
+        "narHash": "sha256-EXBj8a1aBO99CpMZWGqf6z6D/LFdsW/aB2xfDDrJuHw=",
         "ref": "refs/heads/quad/fix/latest-event-in-thread-aggregation",
-        "rev": "35813f52748c31b0b10cc72e69dabef6a838c46a",
-        "revCount": 8067,
+        "rev": "40a4100ec8734d18f8baf8b0dcfea80b6944e90e",
+        "revCount": 8068,
         "type": "git",
         "url": "file:///home/quadradical/Documents/Code/continuwuity"
       },

linux/nix/default.nix

@@ -55,14 +55,10 @@
 
       devShells.default = pkgs.callPackage ./devshell.nix { };
 
-      apps.e2e =
+      apps =
         let
           buildEnv = import ./build_env.nix { inherit pkgs lib; };
-        in
-        {
-          type = "app";
-          program = lib.getExe (
-            pkgs.writeShellApplication {
+          e2e = pkgs.writeShellApplication {
             name = "nexus-e2e";
             runtimeInputs =
               buildEnv.packages
@@ -74,10 +70,37 @@
               ]);
             runtimeEnv = buildEnv.env;
             text = builtins.readFile ./e2e.sh;
+          };
+        in
+        {
+          e2e = {
+            type = "app";
+            program = lib.getExe e2e;
+          };
+
+          e2e-headless = {
+            type = "app";
+            program = lib.getExe (
+              pkgs.writeShellApplication {
+                name = "nexus-e2e-headless";
+                runtimeInputs = [ pkgs.cage ];
+                runtimeEnv = {
+                  WLR_BACKENDS = "headless";
+                  __EGL_VENDOR_LIBRARY_FILENAMES = "${pkgs.mesa}/share/glvnd/egl_vendor.d/50_mesa.json";
+                };
+                text = ''
+                  unset DISPLAY WAYLAND_DISPLAY
+                  # Wayland needs one, which CI may not have
+                  XDG_RUNTIME_DIR="''${XDG_RUNTIME_DIR:-$(mktemp -d)}"
+                  export XDG_RUNTIME_DIR
+
+                  exec cage -- ${lib.getExe e2e} "$@"
+                '';
               }
             );
           };
         };
+    };
 
   flake.nixosModules.default = import ./module.nix self;
 }