Add Cmd+Q quit warning with suppression toggle (#295)

Sources/AppDelegate.swift

@@ -1647,6 +1647,32 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
         return StoredShortcut(key: key, command: command, shift: shift, option: option, control: control)
     }
 
+    private func handleQuitShortcutWarning() -> Bool {
+        if !QuitWarningSettings.isEnabled() {
+            NSApp.terminate(nil)
+            return true
+        }
+
+        let alert = NSAlert()
+        alert.alertStyle = .warning
+        alert.messageText = "Quit cmux?"
+        alert.informativeText = "This will close all windows and workspaces."
+        alert.addButton(withTitle: "Quit")
+        alert.addButton(withTitle: "Cancel")
+        alert.showsSuppressionButton = true
+        alert.suppressionButton?.title = "Don't warn again for Cmd+Q"
+
+        let response = alert.runModal()
+        if alert.suppressionButton?.state == .on {
+            QuitWarningSettings.setEnabled(false)
+        }
+
+        if response == .alertFirstButtonReturn {
+            NSApp.terminate(nil)
+        }
+        return true
+    }
+
     private func handleCustomShortcut(event: NSEvent) -> Bool {
         // `charactersIgnoringModifiers` can be nil for some synthetic NSEvents and certain special keys.
         // Most shortcuts below use keyCode fallbacks, so treat nil as "" rather than bailing out.
@@ -1698,6 +1724,11 @@ final class AppDelegate: NSObject, NSApplicationDelegate, UNUserNotificationCent
             return false
         }
 
+        let normalizedFlags = flags.subtracting([.numericPad, .function])
+        if normalizedFlags == [.command], chars == "q" {
+            return handleQuitShortcutWarning()
+        }
+
         // When the terminal has active IME composition (e.g. Korean, Japanese, Chinese
         // input), don't intercept key events — let them flow through to the input method.
         if let ghosttyView = NSApp.keyWindow?.firstResponder as? GhosttyNSView,

Sources/cmuxApp.swift

@@ -2416,6 +2416,22 @@ enum AppearanceSettings {
     }
 }
 
+enum QuitWarningSettings {
+    static let warnBeforeQuitKey = "warnBeforeQuitShortcut"
+    static let defaultWarnBeforeQuit = true
+
+    static func isEnabled(defaults: UserDefaults = .standard) -> Bool {
+        if defaults.object(forKey: warnBeforeQuitKey) == nil {
+            return defaultWarnBeforeQuit
+        }
+        return defaults.bool(forKey: warnBeforeQuitKey)
+    }
+
+    static func setEnabled(_ isEnabled: Bool, defaults: UserDefaults = .standard) {
+        defaults.set(isEnabled, forKey: warnBeforeQuitKey)
+    }
+}
+
 enum ClaudeCodeIntegrationSettings {
     static let hooksEnabledKey = "claudeCodeHooksEnabled"
     static let defaultHooksEnabled = true
@@ -2446,6 +2462,7 @@ struct SettingsView: View {
     @AppStorage(BrowserLinkOpenSettings.browserHostWhitelistKey) private var browserHostWhitelist = BrowserLinkOpenSettings.defaultBrowserHostWhitelist
     @AppStorage(BrowserInsecureHTTPSettings.allowlistKey) private var browserInsecureHTTPAllowlist = BrowserInsecureHTTPSettings.defaultAllowlistText
     @AppStorage(NotificationBadgeSettings.dockBadgeEnabledKey) private var notificationDockBadgeEnabled = NotificationBadgeSettings.defaultDockBadgeEnabled
+    @AppStorage(QuitWarningSettings.warnBeforeQuitKey) private var warnBeforeQuitShortcut = QuitWarningSettings.defaultWarnBeforeQuit
     @AppStorage(WorkspacePlacementSettings.placementKey) private var newWorkspacePlacement = WorkspacePlacementSettings.defaultPlacement.rawValue
     @AppStorage(WorkspaceAutoReorderSettings.key) private var workspaceAutoReorder = WorkspaceAutoReorderSettings.defaultValue
     @AppStorage(SidebarBranchLayoutSettings.key) private var sidebarBranchVerticalLayout = SidebarBranchLayoutSettings.defaultVerticalLayout
@@ -2542,6 +2559,19 @@ struct SettingsView: View {
 
                         SettingsCardDivider()
 
+                        SettingsCardRow(
+                            "Warn Before Quit",
+                            subtitle: warnBeforeQuitShortcut
+                                ? "Show a confirmation before quitting with Cmd+Q."
+                                : "Cmd+Q quits immediately without confirmation."
+                        ) {
+                            Toggle("", isOn: $warnBeforeQuitShortcut)
+                                .labelsHidden()
+                                .controlSize(.small)
+                        }
+
+                        SettingsCardDivider()
+
                         SettingsCardRow(
                             "Sidebar Branch Layout",
                             subtitle: sidebarBranchVerticalLayout
@@ -2947,6 +2977,7 @@ struct SettingsView: View {
         browserInsecureHTTPAllowlist = BrowserInsecureHTTPSettings.defaultAllowlistText
         browserInsecureHTTPAllowlistDraft = BrowserInsecureHTTPSettings.defaultAllowlistText
         notificationDockBadgeEnabled = NotificationBadgeSettings.defaultDockBadgeEnabled
+        warnBeforeQuitShortcut = QuitWarningSettings.defaultWarnBeforeQuit
         newWorkspacePlacement = WorkspacePlacementSettings.defaultPlacement.rawValue
         workspaceAutoReorder = WorkspaceAutoReorderSettings.defaultValue
         sidebarBranchVerticalLayout = SidebarBranchLayoutSettings.defaultVerticalLayout

cmuxTests/CmuxWebViewKeyEquivalentTests.swift

@@ -886,6 +886,36 @@ final class AppearanceSettingsTests: XCTestCase {
     }
 }
 
+final class QuitWarningSettingsTests: XCTestCase {
+    func testDefaultWarnBeforeQuitIsEnabledWhenUnset() {
+        let suiteName = "QuitWarningSettingsTests.Default.\(UUID().uuidString)"
+        guard let defaults = UserDefaults(suiteName: suiteName) else {
+            XCTFail("Failed to create isolated UserDefaults suite")
+            return
+        }
+        defer { defaults.removePersistentDomain(forName: suiteName) }
+
+        defaults.removeObject(forKey: QuitWarningSettings.warnBeforeQuitKey)
+
+        XCTAssertTrue(QuitWarningSettings.isEnabled(defaults: defaults))
+    }
+
+    func testStoredPreferenceOverridesDefault() {
+        let suiteName = "QuitWarningSettingsTests.Stored.\(UUID().uuidString)"
+        guard let defaults = UserDefaults(suiteName: suiteName) else {
+            XCTFail("Failed to create isolated UserDefaults suite")
+            return
+        }
+        defer { defaults.removePersistentDomain(forName: suiteName) }
+
+        defaults.set(false, forKey: QuitWarningSettings.warnBeforeQuitKey)
+        XCTAssertFalse(QuitWarningSettings.isEnabled(defaults: defaults))
+
+        defaults.set(true, forKey: QuitWarningSettings.warnBeforeQuitKey)
+        XCTAssertTrue(QuitWarningSettings.isEnabled(defaults: defaults))
+    }
+}
+
 final class UpdateChannelSettingsTests: XCTestCase {
     func testResolvedFeedFallsBackWhenInfoFeedMissing() {
         let resolved = UpdateFeedResolver.resolvedFeedURLString(infoFeedURL: nil)