Revert UI test foreground activation changes back to 56a4d258

Reverts cbb21872, 54ec524a, 10fd323b, 75375ab7, 82a16aa7 — all
attempts to fix display resolution UI test foreground activation
on CI that introduced regressions. Restores the state from the
last fully green CI run (56a4d258).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -495,24 +495,12 @@ jobs:
           {"helperBinaryPath":"$HELPER_PATH"}
           EOF
 
-          # Retry once — foreground activation on headless CI runners is flaky
-          for attempt in 1 2; do
-            if xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug \
-              -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
-              -disableAutomaticPackageResolution \
-              -destination "platform=macOS" \
-              -only-testing:cmuxUITests/DisplayResolutionRegressionUITests \
-              test; then
-              exit 0
-            fi
-            if [ "$attempt" -eq 2 ]; then
-              echo "Display resolution UI regression failed after 2 attempts" >&2
-              exit 1
-            fi
-            echo "Attempt $attempt failed, retrying..."
-            pkill -x "cmux DEV" 2>/dev/null || true
-            sleep 3
-          done
+          xcodebuild -project GhosttyTabs.xcodeproj -scheme cmux -configuration Debug \
+            -clonedSourcePackagesDirPath "$SOURCE_PACKAGES_DIR" \
+            -disableAutomaticPackageResolution \
+            -destination "platform=macOS" \
+            -only-testing:cmuxUITests/DisplayResolutionRegressionUITests \
+            test
 
       - name: Run browser find focus UI regression
         run: |

Sources/AppDelegate.swift

@@ -1929,10 +1929,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         Self.cachedIsRunningUnderXCTest
     }
 
-#if DEBUG
-    private var uiTestForegroundActivationInFlight = false
-#endif
-
     private static func detectRunningUnderXCTest(_ env: [String: String]) -> Bool {
         if env["XCTestConfigurationFilePath"] != nil { return true }
         if env["XCTestBundlePath"] != nil { return true }
@@ -2369,7 +2365,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         // In UI tests, `WindowGroup` occasionally fails to materialize a window quickly on the VM.
         // If there are no windows shortly after launch, force-create one so XCUITest can proceed.
         if isRunningUnderXCTest {
-            scheduleUITestForegroundActivationIfNeeded(reason: "didFinishLaunching")
             if let rawVariant = env["CMUX_UI_TEST_BROWSER_IMPORT_HINT_VARIANT"] {
                 UserDefaults.standard.set(
                     BrowserImportHintSettings.variant(for: rawVariant).rawValue,
@@ -2394,7 +2389,7 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
                     self.openNewMainWindow(nil)
                 }
                 self.moveUITestWindowToTargetDisplayIfNeeded()
-                self.scheduleUITestForegroundActivationIfNeeded(reason: "afterForceWindow")
+                NSRunningApplication.current.activate(options: [.activateAllWindows, .activateIgnoringOtherApps])
                 self.writeUITestDiagnosticsIfNeeded(stage: "afterForceWindow")
             }
             if env["CMUX_UI_TEST_BROWSER_IMPORT_HINT_OPEN_BLANK_BROWSER"] == "1" {
@@ -2420,12 +2415,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
 #endif
     }
 
-    func applicationWillFinishLaunching(_ notification: Notification) {
-#if DEBUG
-        scheduleUITestForegroundActivationIfNeeded(reason: "willFinishLaunching")
-#endif
-    }
-
 #if DEBUG
     private func writeUITestDiagnosticsIfNeeded(stage: String) {
         let env = ProcessInfo.processInfo.environment
@@ -2444,8 +2433,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         payload["pid"] = String(ProcessInfo.processInfo.processIdentifier)
         payload["bundleId"] = Bundle.main.bundleIdentifier ?? ""
         payload["isRunningUnderXCTest"] = isRunningUnderXCTest ? "1" : "0"
-        payload["appIsActive"] = NSApp.isActive ? "1" : "0"
-        payload["activationPolicy"] = debugActivationPolicyDescription(NSApp.activationPolicy())
         payload["windowsCount"] = String(windows.count)
         payload["windowIdentifiers"] = ids
         payload["windowVisibleFlags"] = vis
@@ -2577,66 +2564,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         )
     }
 
-    private func scheduleUITestForegroundActivationIfNeeded(reason: String) {
-        let env = ProcessInfo.processInfo.environment
-        guard isRunningUnderXCTest(env) else { return }
-        guard !uiTestForegroundActivationInFlight else { return }
-
-        uiTestForegroundActivationInFlight = true
-        attemptUITestForegroundActivation(reason: reason, attempt: 0)
-    }
-
-    private func attemptUITestForegroundActivation(reason: String, attempt: Int) {
-        let env = ProcessInfo.processInfo.environment
-        guard isRunningUnderXCTest(env) else {
-            uiTestForegroundActivationInFlight = false
-            return
-        }
-
-        if NSApp.activationPolicy() != .regular {
-            _ = NSApp.setActivationPolicy(.regular)
-        }
-        if NSApp.isHidden {
-            NSApp.unhide(nil)
-        }
-
-        let windows = NSApp.windows
-        if let window = windows.first {
-            window.orderFrontRegardless()
-            window.makeKeyAndOrderFront(nil)
-        }
-
-        NSApp.activate(ignoringOtherApps: true)
-        NSRunningApplication.current.activate(options: [.activateAllWindows, .activateIgnoringOtherApps])
-        writeUITestDiagnosticsIfNeeded(stage: "foreground.\(reason).\(attempt)")
-
-        if NSApp.isActive {
-            uiTestForegroundActivationInFlight = false
-            return
-        }
-        guard attempt < 20 else {
-            uiTestForegroundActivationInFlight = false
-            return
-        }
-
-        DispatchQueue.main.asyncAfter(deadline: .now() + 0.25) { [weak self] in
-            self?.attemptUITestForegroundActivation(reason: reason, attempt: attempt + 1)
-        }
-    }
-
-    private func debugActivationPolicyDescription(_ policy: NSApplication.ActivationPolicy) -> String {
-        switch policy {
-        case .regular:
-            return "regular"
-        case .accessory:
-            return "accessory"
-        case .prohibited:
-            return "prohibited"
-        @unknown default:
-            return "unknown(\(policy.rawValue))"
-        }
-    }
-
     private func moveUITestWindowToTargetDisplayIfNeeded(attempt: Int = 0) {
         let env = ProcessInfo.processInfo.environment
         guard let rawDisplayID = env["CMUX_UI_TEST_TARGET_DISPLAY_ID"],
@@ -2677,7 +2604,6 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         window.setFrame(frame, display: true, animate: false)
         window.makeKeyAndOrderFront(nil)
         window.orderFrontRegardless()
-        scheduleUITestForegroundActivationIfNeeded(reason: "afterMoveToTargetDisplay")
         if window.screen?.cmuxDisplayID != targetDisplayID, attempt < 20 {
             DispatchQueue.main.asyncAfter(deadline: .now() + 0.25) { [weak self] in
                 self?.moveUITestWindowToTargetDisplayIfNeeded(attempt: attempt + 1)

cmuxUITests/DisplayResolutionRegressionUITests.swift

@@ -1,10 +1,8 @@
 import XCTest
 import Foundation
-import AppKit
 
 final class DisplayResolutionRegressionUITests: XCTestCase {
     private let defaultDisplayHarnessManifestPath = "/tmp/cmux-ui-test-display-harness.json"
-    private let appBundleIdentifier = "com.cmuxterm.app.debug"
     private var launchTag = ""
     private var diagnosticsPath = ""
     private var displayReadyPath = ""
@@ -13,7 +11,7 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
     private var displayDonePath = ""
     private var helperBinaryPath = ""
     private var helperLogPath = ""
-    private var launchedRunningApp: NSRunningApplication?
+    private var launchedApp: XCUIApplication?
     private var helperProcess: Process?
 
     override func setUp() {
@@ -241,79 +239,18 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
         helperProcess = proc
     }
 
-    // Launch the app via NSWorkspace instead of XCUIApplication to avoid
-    // the 60-second foreground activation timeout that kills UI tests on
-    // headless CI runners. NSWorkspace.openApplication passes environment
-    // variables through OpenConfiguration and returns immediately.
     private func launchAppProcess(targetDisplayID: String) throws {
-        let appBundlePath = try resolveAppBundlePath()
-        let appURL = URL(fileURLWithPath: appBundlePath)
-
-        let config = NSWorkspace.OpenConfiguration()
-        config.environment = launchEnvironment(targetDisplayID: targetDisplayID)
-        config.activates = true
-
-        let semaphore = DispatchSemaphore(value: 0)
-        var launchError: Error?
-        var runningApp: NSRunningApplication?
-
-        NSWorkspace.shared.openApplication(at: appURL, configuration: config) { app, error in
-            runningApp = app
-            launchError = error
-            semaphore.signal()
+        let app = XCUIApplication()
+        for (key, value) in launchEnvironment(targetDisplayID: targetDisplayID) {
+            app.launchEnvironment[key] = value
         }
-
-        let waitResult = semaphore.wait(timeout: .now() + 30.0)
-        if waitResult == .timedOut {
+        app.launch()
+        guard ensureForegroundAfterLaunch(app, timeout: 12.0) else {
             throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
-                NSLocalizedDescriptionKey: "NSWorkspace.openApplication timed out after 30s for \(appBundlePath)"
+                NSLocalizedDescriptionKey: "XCUIApplication failed to reach foreground. state=\(app.state.rawValue)"
             ])
         }
-
-        if let error = launchError {
-            throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
-                NSLocalizedDescriptionKey: "NSWorkspace.openApplication failed: \(error.localizedDescription) path=\(appBundlePath)"
-            ])
-        }
-
-        launchedRunningApp = runningApp
-
-        if !waitForAppLaunchDiagnostics(timeout: 15.0) {
-            let isAlive = launchedRunningApp?.isTerminated == false
-            throw NSError(domain: "DisplayResolutionRegressionUITests", code: 2, userInfo: [
-                NSLocalizedDescriptionKey: "App failed to write launch diagnostics. alive=\(isAlive) diagnostics=\(loadDiagnostics() ?? [:])"
-            ])
-        }
-    }
-
-    private func resolveAppBundlePath() throws -> String {
-        let testBundle = Bundle(for: Self.self)
-        // UI test bundle is at:
-        //   .../Build/Products/Debug/cmuxUITests-Runner.app/Contents/PlugIns/cmuxUITests.xctest
-        // The app is at:
-        //   .../Build/Products/Debug/cmux DEV.app
-        let productsDir = testBundle.bundleURL
-            .deletingLastPathComponent()  // PlugIns/
-            .deletingLastPathComponent()  // Contents/
-            .deletingLastPathComponent()  // cmuxUITests-Runner.app/
-        let appPath = productsDir.appendingPathComponent("cmux DEV.app").path
-        if FileManager.default.fileExists(atPath: appPath) {
-            return appPath
-        }
-
-        // Fallback: search DerivedData for the app
-        let env = ProcessInfo.processInfo.environment
-        if let builtProductsDir = env["BUILT_PRODUCTS_DIR"], !builtProductsDir.isEmpty {
-            let candidate = URL(fileURLWithPath: builtProductsDir)
-                .appendingPathComponent("cmux DEV.app").path
-            if FileManager.default.fileExists(atPath: candidate) {
-                return candidate
-            }
-        }
-
-        throw NSError(domain: "DisplayResolutionRegressionUITests", code: 4, userInfo: [
-            NSLocalizedDescriptionKey: "App bundle not found. primary=\(appPath) BUILT_PRODUCTS_DIR=\(env["BUILT_PRODUCTS_DIR"] ?? "<unset>")"
-        ])
+        launchedApp = app
     }
 
     private func launchEnvironment(targetDisplayID: String) -> [String: String] {
@@ -327,25 +264,31 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
     }
 
     private func terminateLaunchedAppIfNeeded() {
-        guard let app = launchedRunningApp else { return }
-        defer { launchedRunningApp = nil }
+        guard let launchedApp else { return }
+        defer { self.launchedApp = nil }
 
-        if app.isTerminated { return }
+        if launchedApp.state == .notRunning {
+            return
+        }
 
-        app.terminate()
-        // Wait up to 5s for termination
-        let deadline = Date().addingTimeInterval(5.0)
-        while !app.isTerminated && Date() < deadline {
-            RunLoop.current.run(until: Date().addingTimeInterval(0.1))
-        }
-        if !app.isTerminated {
-            app.forceTerminate()
-        }
+        launchedApp.terminate()
+        _ = launchedApp.wait(for: .notRunning, timeout: 5.0)
     }
 
     private func launchedAppDiagnostics() -> String {
-        guard let app = launchedRunningApp else { return "not-launched" }
-        return "pid=\(app.processIdentifier) terminated=\(app.isTerminated)"
+        guard let launchedApp else { return "not-launched" }
+        return "state=\(launchedApp.state.rawValue)"
+    }
+
+    private func ensureForegroundAfterLaunch(_ app: XCUIApplication, timeout: TimeInterval) -> Bool {
+        if app.wait(for: .runningForeground, timeout: timeout) {
+            return true
+        }
+        if app.state == .runningBackground {
+            app.activate()
+            return app.wait(for: .runningForeground, timeout: 6.0)
+        }
+        return false
     }
 
     private func waitForTargetDisplayMove(targetDisplayID: String, timeout: TimeInterval) -> Bool {
@@ -412,15 +355,6 @@ final class DisplayResolutionRegressionUITests: XCTestCase {
             .deletingLastPathComponent()
     }
 
-    private func waitForAppLaunchDiagnostics(timeout: TimeInterval) -> Bool {
-        waitForCondition(timeout: timeout) {
-            guard let diagnostics = self.loadDiagnostics() else { return false }
-            guard let pid = diagnostics["pid"], !pid.isEmpty else { return false }
-            guard let stage = diagnostics["stage"], !stage.isEmpty else { return false }
-            return true
-        }
-    }
-
     private func removeTestArtifacts() {
         for path in [
             diagnosticsPath,