macos: add UI test for window position restore across titlebar styles

Tests that window position and size are correctly restored after
reopen for all four macos-titlebar-style variants.

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

macos/GhosttyUITests/GhosttyWindowPositionUITests.swift

@@ -0,0 +1,158 @@
+//
+//  GhosttyWindowPositionUITests.swift
+//  GhosttyUITests
+//
+//  Created by Claude on 2026-03-11.
+//
+
+import XCTest
+
+final class GhosttyWindowPositionUITests: GhosttyCustomConfigCase {
+    override static var runsForEachTargetApplicationUIConfiguration: Bool { false }
+
+    // MARK: - Restore round-trip per titlebar style
+
+    @MainActor func testRestoredNative() throws { try runRestoreTest(titlebarStyle: "native") }
+    @MainActor func testRestoredHidden() throws { try runRestoreTest(titlebarStyle: "hidden") }
+    @MainActor func testRestoredTransparent() throws { try runRestoreTest(titlebarStyle: "transparent") }
+    @MainActor func testRestoredTabs() throws { try runRestoreTest(titlebarStyle: "tabs") }
+
+    // MARK: - Config overrides cached position/size
+
+    @MainActor
+    func testConfigOverridesCachedPositionAndSize() async throws {
+        // Launch maximized so the cached frame is fullscreen-sized.
+        try updateConfig(
+            """
+            maximize = true
+            title = "GhosttyWindowPositionUITests"
+            """
+        )
+
+        let app = try ghosttyApplication()
+        app.launch()
+
+        let window = app.windows.firstMatch
+        XCTAssertTrue(window.waitForExistence(timeout: 5), "Window should appear")
+
+        let maximizedFrame = window.frame
+
+        // Now update the config with a small explicit size and position,
+        // reload, and open a new window. It should respect the config, not the cache.
+        try updateConfig(
+            """
+            window-position-x = 50
+            window-position-y = 50
+            window-width = 30
+            window-height = 30
+            title = "GhosttyWindowPositionUITests"
+            """
+        )
+        app.typeKey(",", modifierFlags: [.command, .shift])
+        try await Task.sleep(for: .seconds(0.5))
+        app.typeKey("n", modifierFlags: [.command])
+
+        XCTAssertEqual(app.windows.count, 2, "Should have 2 windows")
+        let newWindow = app.windows.element(boundBy: 0)
+        let newFrame = newWindow.frame
+
+        // The new window should be smaller than the maximized one.
+        XCTAssertLessThan(newFrame.size.width, maximizedFrame.size.width,
+                          "30 columns should be narrower than maximized")
+        XCTAssertLessThan(newFrame.size.height, maximizedFrame.size.height,
+                          "30 rows should be shorter than maximized")
+
+        app.terminate()
+    }
+
+    // MARK: - Size-only config change preserves position
+
+    @MainActor
+    func testSizeOnlyConfigPreservesPosition() async throws {
+        // Launch maximized so the window has a known position (top-left of visible frame).
+        try updateConfig(
+            """
+            maximize = true
+            title = "GhosttyWindowPositionUITests"
+            """
+        )
+
+        let app = try ghosttyApplication()
+        app.launch()
+
+        let window = app.windows.firstMatch
+        XCTAssertTrue(window.waitForExistence(timeout: 5), "Window should appear")
+
+        let initialFrame = window.frame
+
+        // Reload with only size changed, close current window, open new one.
+        // Position should be restored from cache.
+        try updateConfig(
+            """
+            window-width = 30
+            window-height = 30
+            title = "GhosttyWindowPositionUITests"
+            """
+        )
+        app.typeKey(",", modifierFlags: [.command, .shift])
+        try await Task.sleep(for: .seconds(0.5))
+        app.typeKey("w", modifierFlags: [.command])
+        app.typeKey("n", modifierFlags: [.command])
+
+        let newWindow = app.windows.firstMatch
+        XCTAssertTrue(newWindow.waitForExistence(timeout: 5), "New window should appear")
+
+        let newFrame = newWindow.frame
+
+        // Position should be preserved from the cached value.
+        // Compare x and maxY since the window is anchored at the top-left
+        // but AppKit uses bottom-up coordinates (origin.y changes with height).
+        XCTAssertEqual(newFrame.origin.x, initialFrame.origin.x, accuracy: 2,
+                        "x position should not change with size-only config")
+        XCTAssertEqual(newFrame.maxY, initialFrame.maxY, accuracy: 2,
+                        "top edge (maxY) should not change with size-only config")
+
+        app.terminate()
+    }
+
+    // MARK: - Shared round-trip helper
+
+    /// Opens a new window, records its frame, closes it, opens another,
+    /// and verifies the frame is restored consistently.
+    private func runRestoreTest(titlebarStyle: String) throws {
+        try updateConfig(
+            """
+            macos-titlebar-style = \(titlebarStyle)
+            title = "GhosttyWindowPositionUITests"
+            """
+        )
+
+        let app = try ghosttyApplication()
+        app.launch()
+
+        let window = app.windows.firstMatch
+        XCTAssertTrue(window.waitForExistence(timeout: 5), "Window should appear")
+
+        let firstFrame = window.frame
+
+        // Close the window and open a new one — it should restore the same frame.
+        app.typeKey("w", modifierFlags: [.command])
+        app.typeKey("n", modifierFlags: [.command])
+
+        let window2 = app.windows.firstMatch
+        XCTAssertTrue(window2.waitForExistence(timeout: 5), "New window should appear")
+
+        let restoredFrame = window2.frame
+
+        XCTAssertEqual(restoredFrame.origin.x, firstFrame.origin.x, accuracy: 2,
+                        "[\(titlebarStyle)] x position should be restored")
+        XCTAssertEqual(restoredFrame.origin.y, firstFrame.origin.y, accuracy: 2,
+                        "[\(titlebarStyle)] y position should be restored")
+        XCTAssertEqual(restoredFrame.size.width, firstFrame.size.width, accuracy: 2,
+                        "[\(titlebarStyle)] width should be restored")
+        XCTAssertEqual(restoredFrame.size.height, firstFrame.size.height, accuracy: 2,
+                        "[\(titlebarStyle)] height should be restored")
+
+        app.terminate()
+    }
+}