CI: open the PC app's main window and fail on QML warnings

.github/workflows/ci.yml

@@ -85,6 +85,9 @@ jobs:
       - name: Installer
         shell: pwsh
         run: ./scripts/package.ps1 -SkipBuild
+      - name: Open the main window, with no QML warnings
+        shell: pwsh
+        run: ./scripts/ui-check.ps1
       - name: Install, run and uninstall it
         shell: pwsh
         run: ./scripts/smoke-installer.ps1

desktop/app/cpp/app_helpers.cpp

@@ -79,7 +79,37 @@ void register_qml_app_engine(QQmlApplicationEngine &engine)
 #include <QtCore/QStandardPaths>
 #include <QtCore/QTextStream>
 
+#include <atomic>
+#include <cstdio>
+
 namespace {
+std::atomic<int> &qmlProblems()
+{
+    static std::atomic<int> count { 0 };
+    return count;
+}
+
+// A warning or error from QML: a component that didn't load, a binding or
+// a script that failed.
+bool isQmlProblem(QtMsgType type, const QMessageLogContext &ctx, const QString &msg)
+{
+    if (type != QtWarningMsg && type != QtCriticalMsg && type != QtFatalMsg)
+        return false;
+    return (ctx.file && QByteArray(ctx.file).startsWith("qrc:/")) || msg.contains(QStringLiteral("qrc:/"));
+}
+
+// `--ui-check`: messages go to stderr, not the log file, and QML problems
+// are counted.
+void uiCheckMessageHandler(QtMsgType type, const QMessageLogContext &ctx, const QString &msg)
+{
+    if (type == QtDebugMsg)
+        return;
+    if (isQmlProblem(type, ctx, msg))
+        qmlProblems().fetch_add(1);
+    std::fprintf(stderr, "[%d] %s (%s:%d)\n", int(type), qUtf8Printable(msg), ctx.file ? ctx.file : "", ctx.line);
+    std::fflush(stderr);
+}
+
 void qtLogMessageHandler(QtMsgType type, const QMessageLogContext &ctx, const QString &msg)
 {
     if (type == QtDebugMsg)
@@ -102,6 +132,17 @@ void prepare_qt()
     prepare_qt_without_log();
 }
 
+void prepare_qt_for_ui_check()
+{
+    qInstallMessageHandler(uiCheckMessageHandler);
+    prepare_qt_without_log();
+}
+
+int32_t qml_problem_count()
+{
+    return qmlProblems().load();
+}
+
 void prepare_qt_without_log()
 {
     // Windows get an alpha channel so the Mica backdrop can show through, and

desktop/app/cpp/app_helpers.h

@@ -8,6 +8,8 @@
 // Qt setup that must happen before QGuiApplication is created.
 void prepare_qt();
 void prepare_qt_without_log();
+void prepare_qt_for_ui_check();
+int32_t qml_problem_count();
 
 // Adds one size of the app icon (straight-alpha RGBA, size x size).
 void add_app_icon_image(int32_t size, rust::Slice<const uint8_t> rgba);

desktop/app/src/bridge/native.rs

@@ -20,6 +20,12 @@ pub mod ffi {
         /// Like `prepare_qt`, without the QML log file: for the installer
         /// and uninstaller, which mustn't create the app's data folder.
         fn prepare_qt_without_log();
+        /// Like `prepare_qt`, for `--ui-check`: Qt's messages go to stderr
+        /// instead of the log file, and QML warnings and errors are counted.
+        fn prepare_qt_for_ui_check();
+        /// How many QML warnings and errors there were since
+        /// `prepare_qt_for_ui_check`.
+        fn qml_problem_count() -> i32;
         fn add_app_icon_image(size: i32, rgba: &[u8]);
         fn apply_app_icon();
         fn keep_running_without_windows();

desktop/app/src/main.rs

@@ -234,8 +234,16 @@ struct Options {
     /// The uninstaller's window (`--remove [--installed <folder>]`).
     remove: bool,
     installed: Option<PathBuf>,
+    /// `--ui-check` (needs `--data-dir`): open the main window, quit after
+    /// [`UI_CHECK_SECONDS`], and fail if QML reported a warning or an error.
+    /// Qt's messages go to stderr. For CI (`scripts/ui-check.ps1`).
+    ui_check: bool,
 }
 
+/// How long `--ui-check` keeps the window open: long enough for the window
+/// to load, be restored and settle.
+const UI_CHECK_SECONDS: u64 = 8;
+
 fn parse_options() -> Options {
     parse_options_from(std::env::args_os().skip(1))
 }
@@ -264,6 +272,10 @@ fn parse_options_from<I: IntoIterator<Item = std::ffi::OsString>>(iter: I) -> Op
                 in_share = false;
                 options.uninstall = true;
             }
+            Some("--ui-check") => {
+                in_share = false;
+                options.ui_check = true;
+            }
             Some(setup::SETUP_ARG) => {
                 in_share = false;
                 options.setup = Some(PathBuf::new());
@@ -465,6 +477,11 @@ fn main() -> ExitCode {
             }
         };
     }
+    // The check starts the whole app, so never on the user's own data.
+    if options.ui_check && options.data_dir.is_none() {
+        eprintln!("nectarlink: --ui-check needs --data-dir");
+        return ExitCode::FAILURE;
+    }
     let data_dir = options.data_dir.clone().unwrap_or_else(default_data_dir);
     if let Err(e) = std::fs::create_dir_all(&data_dir) {
         eprintln!("nectarlink: can't create {}: {e}", data_dir.display());
@@ -595,7 +612,11 @@ fn main() -> ExitCode {
         send_to::handle(request);
     }
 
-    bridge::native::ffi::prepare_qt();
+    if options.ui_check {
+        bridge::native::ffi::prepare_qt_for_ui_check();
+    } else {
+        bridge::native::ffi::prepare_qt();
+    }
     let mut app = QGuiApplication::new();
     if let Some(mut app) = app.as_mut() {
         app.as_mut().set_application_name(&QString::from("Nectarlink"));
@@ -630,6 +651,12 @@ fn main() -> ExitCode {
         bridge::native::ffi::register_qml_app_engine(engine.as_mut());
         engine.load(&QUrl::from("qrc:/qt/qml/app/nectarlink/qml/App.qml"));
     }
+    if options.ui_check {
+        std::thread::spawn(|| {
+            std::thread::sleep(Duration::from_secs(UI_CHECK_SECONDS));
+            bridge::app::request_quit();
+        });
+    }
     let code = app.as_mut().map_or(1, |app| app.exec());
 
     tracing::info!(code, "shutting down");
@@ -644,6 +671,14 @@ fn main() -> ExitCode {
     win::net::stop();
     core_host::shutdown();
     drop(app);
+    if options.ui_check {
+        let problems = bridge::native::ffi::qml_problem_count();
+        if problems > 0 {
+            eprintln!("nectarlink: --ui-check: {problems} QML warning(s) or error(s), see above");
+            return ExitCode::FAILURE;
+        }
+        eprintln!("nectarlink: --ui-check: no QML warnings");
+    }
     ExitCode::from(u8::try_from(code).unwrap_or(1))
 }
 
@@ -672,6 +707,17 @@ mod tests {
         );
     }
 
+    #[test]
+    fn parse_options_recognizes_ui_check_flag() {
+        let opts = parse_options_from(
+            ["--ui-check", "--data-dir", r"C:\Temp\nectarlink-test"].into_iter().map(OsString::from),
+        );
+        assert!(opts.ui_check);
+        assert!(!opts.minimized);
+        assert_eq!(opts.data_dir, Some(PathBuf::from(r"C:\Temp\nectarlink-test")));
+        assert!(!parse_options_from(["--minimized"].into_iter().map(OsString::from)).ui_check);
+    }
+
     #[test]
     fn parse_options_recognizes_task_flag() {
         let find_opts = parse_options_from(

scripts/ui-check.ps1

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+<#
+.SYNOPSIS
+  Opens the Windows app's main window for a few seconds and fails on any
+  QML warning or error.
+
+.DESCRIPTION
+  Runs nectarlink-desktop.exe --ui-check with a new data folder under
+  target\ui-check, so the user's own data is never touched, and without
+  USB (NECTARLINK_NO_ADB=1). The app shows the main window, quits after a
+  few seconds and exits with an error if QML reported a problem, such as a
+  component that didn't load. The QML tests can't catch that for the app's
+  windows, which need the Rust singletons and NativeWindow.
+
+  -Exe defaults to the staged package (scripts\package.ps1), which has its
+  Qt libraries next to it; for target\release, pass -Exe and have Qt's bin
+  folder on PATH.
+
+.EXAMPLE
+  .\scripts\package.ps1 -StageOnly; .\scripts\ui-check.ps1
+#>
+param(
+    [string]$Exe
+)
+
+$ErrorActionPreference = 'Stop'
+$repo = Split-Path -Parent $PSScriptRoot
+if (-not $Exe) { $Exe = Join-Path $repo 'target\package\Nectarlink\nectarlink-desktop.exe' }
+if (-not (Test-Path $Exe)) { throw "$Exe not found; run scripts\package.ps1 -StageOnly first, or pass -Exe" }
+
+$data = Join-Path $repo 'target\ui-check'
+if (Test-Path $data) { Remove-Item -Recurse -Force $data }
+New-Item -ItemType Directory -Force $data | Out-Null
+$stderr = Join-Path $data 'stderr.txt'
+
+$env:NECTARLINK_NO_ADB = '1'
+$app = Start-Process $Exe -ArgumentList '--ui-check', '--data-dir', "`"$data`"" `
+    -RedirectStandardError $stderr -PassThru -NoNewWindow
+# Without the handle, ExitCode stays empty after the process exits.
+$null = $app.Handle
+if (-not $app.WaitForExit(120000)) {
+    $app.Kill()
+    throw "the app didn't quit within 2 minutes"
+}
+Get-Content $stderr | Write-Host
+if ($app.ExitCode -ne 0) { throw "UI check failed (exit code $($app.ExitCode))" }