[camera_avfoundation] Migrate tests to Swift - part 2 (flutter#8613)

This PR migrates some of Objective-C tests to Swift as a part of Swift migration: [flutter/flutter/issues/119109](flutter/flutter#119109).

I kept the names of test cases the same.

Tests migrated in this PR:
- CameraCaptureSessionQueueRaceConditionTests
- CameraMethodChannelTests
- CameraOrientationTests
- CameraSettingsTests
- CameraSessionPresetsTests

Author: FirentisTFW

packages/camera/camera_avfoundation/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.18+8
+
+* Migrates unit tests to Swift.
+
 ## 0.9.18+7
 
 * Fixes crash when setting `activeFormat` on `FLTCaptureDevice`.

packages/camera/camera_avfoundation/example/ios/Runner.xcodeproj/project.pbxproj

@@ -0,0 +1,54 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import XCTest
+
+@testable import camera_avfoundation
+
+final class CameraCaptureSessionQueueRaceConditionTests: XCTestCase {
+  private func createCameraPlugin() -> CameraPlugin {
+    return CameraPlugin(
+      registry: MockFlutterTextureRegistry(),
+      messenger: MockFlutterBinaryMessenger(),
+      globalAPI: MockGlobalEventApi(),
+      deviceDiscoverer: MockCameraDeviceDiscoverer(),
+      deviceFactory: { _ in MockCaptureDevice() },
+      captureSessionFactory: { MockCaptureSession() },
+      captureDeviceInputFactory: MockCaptureDeviceInputFactory()
+    )
+  }
+
+  func testFixForCaptureSessionQueueNullPointerCrashDueToRaceCondition() {
+    let cameraPlugin = createCameraPlugin()
+    let disposeExpectation = expectation(description: "dispose's result block must be called")
+    let createExpectation = expectation(description: "create's result block must be called")
+
+    // Mimic a dispose call followed by a create call, which can be triggered by slightly dragging the
+    // home bar, causing the app to be inactive, and immediately regain active.
+    cameraPlugin.disposeCamera(0) { error in
+      disposeExpectation.fulfill()
+    }
+
+    cameraPlugin.createCameraOnSessionQueue(
+      withName: "acamera",
+      settings: FCPPlatformMediaSettings.make(
+        with: .medium,
+        framesPerSecond: nil,
+        videoBitrate: nil,
+        audioBitrate: nil,
+        enableAudio: true
+      )
+    ) { result, error in
+      createExpectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+
+    // `captureSessionQueue` must not be nil after `create` call. Otherwise a nil
+    // `captureSessionQueue` passed into `AVCaptureVideoDataOutput::setSampleBufferDelegate:queue:`
+    // API will cause a crash.
+    XCTAssertNotNil(
+      cameraPlugin.captureSessionQueue, "captureSessionQueue must not be nil after create method.")
+  }
+}

packages/camera/camera_avfoundation/example/ios/RunnerTests/CameraCaptureSessionQueueRaceConditionTests.m

@@ -0,0 +1,78 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import AVFoundation
+import XCTest
+
+@testable import camera_avfoundation
+
+final class CameraMethodChannelTests: XCTestCase {
+  private func createCameraPlugin(with session: MockCaptureSession) -> CameraPlugin {
+    return CameraPlugin(
+      registry: MockFlutterTextureRegistry(),
+      messenger: MockFlutterBinaryMessenger(),
+      globalAPI: MockGlobalEventApi(),
+      deviceDiscoverer: MockCameraDeviceDiscoverer(),
+      deviceFactory: { _ in MockCaptureDevice() },
+      captureSessionFactory: { session },
+      captureDeviceInputFactory: MockCaptureDeviceInputFactory()
+    )
+  }
+
+  func testCreate_ShouldCallResultOnMainThread() {
+    let avCaptureSessionMock = MockCaptureSession()
+    avCaptureSessionMock.canSetSessionPreset = true
+    let camera = createCameraPlugin(with: avCaptureSessionMock)
+    let expectation = self.expectation(description: "Result finished")
+
+    var resultValue: NSNumber?
+    camera.createCameraOnSessionQueue(
+      withName: "acamera",
+      settings: FCPPlatformMediaSettings.make(
+        with: FCPPlatformResolutionPreset.medium,
+        framesPerSecond: nil,
+        videoBitrate: nil,
+        audioBitrate: nil,
+        enableAudio: true
+      )
+    ) { result, error in
+      resultValue = result
+      expectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+    XCTAssertNotNil(resultValue)
+  }
+
+  func testDisposeShouldDeallocCamera() {
+    let avCaptureSessionMock = MockCaptureSession()
+    avCaptureSessionMock.canSetSessionPreset = true
+    let camera = createCameraPlugin(with: avCaptureSessionMock)
+    let createExpectation = self.expectation(description: "create's result block must be called")
+
+    camera.createCameraOnSessionQueue(
+      withName: "acamera",
+      settings: FCPPlatformMediaSettings.make(
+        with: .medium,
+        framesPerSecond: nil,
+        videoBitrate: nil,
+        audioBitrate: nil,
+        enableAudio: true
+      )
+    ) { result, error in
+      createExpectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+    XCTAssertNotNil(camera.camera)
+
+    let disposeExpectation = self.expectation(description: "dispose's result block must be called")
+    camera.disposeCamera(0) { error in
+      disposeExpectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+    XCTAssertNil(camera.camera, "camera should be deallocated after dispose")
+  }
+}