Automatic Accessibility Audits on previews part 1 (#4322)

* setup target

* accessibility tests implementation

* removed ipad check

* pr improvements

* updated project

AccessibilityTests/Sources/Application.swift

@@ -0,0 +1,41 @@
+//
+// Copyright 2022-2024 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import XCTest
+
+enum Application {
+    static func launch(viewID: String) -> XCUIApplication {
+        checkEnvironments()
+        
+        let app = XCUIApplication()
+        
+        let launchEnvironment = [
+            "ACCESSIBILITY_VIEW": viewID
+        ]
+        
+        app.launchEnvironment = launchEnvironment
+        app.launch()
+        return app
+    }
+    
+    private static func checkEnvironments() {
+        let requirediPhoneSimulator = "iPhone17,3" // iPhone 16
+        let requiredOSVersion = 18
+        
+        let osVersion = ProcessInfo().operatingSystemVersion
+        guard osVersion.majorVersion == requiredOSVersion else {
+            fatalError("Switch to iOS \(requiredOSVersion) for these tests.")
+        }
+        
+        guard let deviceModel = ProcessInfo().environment["SIMULATOR_MODEL_IDENTIFIER"] else {
+            fatalError("Unknown simulator.")
+        }
+        guard deviceModel == requirediPhoneSimulator else {
+            fatalError("Running on \(deviceModel) but we only support \(requirediPhoneSimulator)")
+        }
+    }
+}

AccessibilityTests/Sources/Test.swift

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+//
+// Copyright 2025 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import XCTest
+
+@MainActor
+class Test: XCTestCase {
+    var app: XCUIApplication!
+    
+    func test() async throws {
+        let client = try UITestsSignalling.Client(mode: .tests)
+        app = Application.launch(viewID: "SecureBackupLogoutConfirmationScreen_Previews")
+        await client.waitForApp()
+        defer { try? client.stop() }
+        
+        try client.send(.accessibilityAudit(.nextPreview))
+        forLoop: for await signal in client.signals.values {
+            switch signal {
+            case .accessibilityAudit(let auditSignal):
+                switch auditSignal {
+                case .nextPreviewReady(let name):
+                    try? app.performAccessibilityAudit { issue in
+                        XCTFail("\(name): \(issue)")
+                        return true
+                    }
+                    try? client.send(.accessibilityAudit(.nextPreview))
+                case .noMorePreviews:
+                    break forLoop
+                default:
+                    fatalError("Unhandled signal")
+                }
+            default:
+                fatalError("Unhandled signal")
+            }
+        }
+        
+        app.terminate()
+    }
+}