[camera_avfoundation] Migrate tests to Swift - part 1 (#8603)

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. I also left most of the implementation comments, although I removed some of them that I considered not very helpful (e.g. "Run test").

Tests migrated in this PR:
- AvailableCamerasTests
- CameraExposureTests
- CameraFocusTests
- CameraPermissionTests
- CameraPreviewPauseTests
- CameraPropertiesTests
- QueueUtilsTests

packages/camera/camera_avfoundation/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.9.18+5
+
+* Migrates unit tests to Swift.
+
 ## 0.9.18+4
 
 * Refactors implementations to reduce usage of OCMock in internal testing.

packages/camera/camera_avfoundation/example/ios/RunnerTests/AvailableCamerasTests.swift

@@ -0,0 +1,120 @@
+// 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 AvailableCamerasTest: XCTestCase {
+  private func createCameraPlugin(with deviceDiscoverer: MockCameraDeviceDiscoverer) -> CameraPlugin
+  {
+    return CameraPlugin(
+      registry: MockFlutterTextureRegistry(),
+      messenger: MockFlutterBinaryMessenger(),
+      globalAPI: MockGlobalEventApi(),
+      deviceDiscoverer: deviceDiscoverer,
+      deviceFactory: { _ in MockCaptureDevice() },
+      captureSessionFactory: { MockCaptureSession() },
+      captureDeviceInputFactory: MockCaptureDeviceInputFactory()
+    )
+  }
+
+  func testAvailableCamerasShouldReturnAllCamerasOnMultiCameraIPhone() {
+    let mockDeviceDiscoverer = MockCameraDeviceDiscoverer()
+    let cameraPlugin = createCameraPlugin(with: mockDeviceDiscoverer)
+    let expectation = self.expectation(description: "Result finished")
+
+    // iPhone 13 Cameras:
+    let wideAngleCamera = MockCaptureDevice()
+    wideAngleCamera.uniqueID = "0"
+    wideAngleCamera.position = .back
+
+    let frontFacingCamera = MockCaptureDevice()
+    frontFacingCamera.uniqueID = "1"
+    frontFacingCamera.position = .front
+
+    let ultraWideCamera = MockCaptureDevice()
+    ultraWideCamera.uniqueID = "2"
+    ultraWideCamera.position = .back
+
+    let telephotoCamera = MockCaptureDevice()
+    telephotoCamera.uniqueID = "3"
+    telephotoCamera.position = .back
+
+    var requiredTypes: [AVCaptureDevice.DeviceType] = [
+      .builtInWideAngleCamera, .builtInTelephotoCamera,
+    ]
+    if #available(iOS 13.0, *) {
+      requiredTypes.append(.builtInUltraWideCamera)
+    }
+    var cameras: [MockCaptureDevice] = [wideAngleCamera, frontFacingCamera, telephotoCamera]
+    if #available(iOS 13.0, *) {
+      cameras.append(ultraWideCamera)
+    }
+
+    mockDeviceDiscoverer.discoverySessionStub = { deviceTypes, mediaType, position in
+      XCTAssertEqual(deviceTypes, requiredTypes)
+      XCTAssertEqual(mediaType, .video)
+      XCTAssertEqual(position, .unspecified)
+      return cameras
+    }
+
+    var resultValue: [FCPPlatformCameraDescription]?
+    cameraPlugin.availableCameras { result, error in
+      XCTAssertNil(error)
+      resultValue = result
+      expectation.fulfill()
+    }
+    waitForExpectations(timeout: 30, handler: nil)
+
+    // Verify the result.
+    if #available(iOS 13.0, *) {
+      XCTAssertEqual(resultValue?.count, 4)
+    } else {
+      XCTAssertEqual(resultValue?.count, 3)
+    }
+  }
+
+  func testAvailableCamerasShouldReturnOneCameraOnSingleCameraIPhone() {
+    let mockDeviceDiscoverer = MockCameraDeviceDiscoverer()
+    let cameraPlugin = createCameraPlugin(with: mockDeviceDiscoverer)
+    let expectation = self.expectation(description: "Result finished")
+
+    // iPhone 8 Cameras:
+    let wideAngleCamera = MockCaptureDevice()
+    wideAngleCamera.uniqueID = "0"
+    wideAngleCamera.position = .back
+
+    let frontFacingCamera = MockCaptureDevice()
+    frontFacingCamera.uniqueID = "1"
+    frontFacingCamera.position = .front
+
+    var requiredTypes: [AVCaptureDevice.DeviceType] = [
+      .builtInWideAngleCamera, .builtInTelephotoCamera,
+    ]
+    if #available(iOS 13.0, *) {
+      requiredTypes.append(.builtInUltraWideCamera)
+    }
+    let cameras: [MockCaptureDevice] = [wideAngleCamera, frontFacingCamera]
+
+    mockDeviceDiscoverer.discoverySessionStub = { deviceTypes, mediaType, position in
+      XCTAssertEqual(deviceTypes, requiredTypes)
+      XCTAssertEqual(mediaType, .video)
+      XCTAssertEqual(position, .unspecified)
+      return cameras
+    }
+
+    var resultValue: [FCPPlatformCameraDescription]?
+    cameraPlugin.availableCameras { result, error in
+      XCTAssertNil(error)
+      resultValue = result
+      expectation.fulfill()
+    }
+    waitForExpectations(timeout: 30, handler: nil)
+
+    // Verify the result.
+    XCTAssertEqual(resultValue?.count, 2)
+  }
+}

packages/camera/camera_avfoundation/example/ios/RunnerTests/CameraExposureTests.swift

@@ -0,0 +1,66 @@
+// 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 CameraExposureTests: XCTestCase {
+  private func createSutAndMocks() -> (FLTCam, MockCaptureDevice, MockDeviceOrientationProvider) {
+    let mockDevice = MockCaptureDevice()
+    let mockDeviceOrientationProvider = MockDeviceOrientationProvider()
+
+    let configuration = FLTCreateTestCameraConfiguration()
+    configuration.captureDeviceFactory = { mockDevice }
+    configuration.deviceOrientationProvider = mockDeviceOrientationProvider
+    let camera = FLTCreateCamWithConfiguration(configuration)
+
+    return (camera, mockDevice, mockDeviceOrientationProvider)
+  }
+
+  func testSetExposurePointWithResult_SetsExposurePointOfInterest() {
+    let (camera, mockDevice, mockDeviceOrientationProvider) = createSutAndMocks()
+    // UI is currently in landscape left orientation.
+    mockDeviceOrientationProvider.orientation = .landscapeLeft
+    // Exposure point of interest is supported.
+    mockDevice.exposurePointOfInterestSupported = true
+
+    // Verify the focus point of interest has been set.
+    var setPoint = CGPoint.zero
+    mockDevice.setExposurePointOfInterestStub = { point in
+      if point == CGPoint(x: 1, y: 1) {
+        setPoint = point
+      }
+    }
+
+    let completionExpectation = expectation(description: "Completion called")
+    camera.setExposurePoint(FCPPlatformPoint.makeWith(x: 1, y: 1)) { error in
+      XCTAssertNil(error)
+      completionExpectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+    XCTAssertEqual(setPoint, CGPoint(x: 1.0, y: 1.0))
+  }
+
+  func testSetExposurePoint_WhenNotSupported_ReturnsError() {
+    let (camera, mockDevice, mockDeviceOrientationProvider) = createSutAndMocks()
+    // UI is currently in landscape left orientation.
+    mockDeviceOrientationProvider.orientation = .landscapeLeft
+    // Exposure point of interest is not supported.
+    mockDevice.exposurePointOfInterestSupported = false
+
+    let expectation = self.expectation(description: "Completion with error")
+
+    camera.setExposurePoint(FCPPlatformPoint.makeWith(x: 1, y: 1)) { error in
+      XCTAssertNotNil(error)
+      XCTAssertEqual(error?.code, "setExposurePointFailed")
+      XCTAssertEqual(error?.message, "Device does not have exposure point capabilities")
+      expectation.fulfill()
+    }
+
+    waitForExpectations(timeout: 30, handler: nil)
+  }
+}