Updated object detector tests to use delegates

mediapipe/tasks/ios/test/vision/object_detector/MPPObjectDetectorTests.m

@@ -25,6 +25,8 @@ static NSDictionary *const kCatsAndDogsRotatedImage =
 static NSString *const kExpectedErrorDomain = @"com.google.mediapipe.tasks";
 static const float pixelDifferenceTolerance = 10.0f;
 static const float scoreDifferenceTolerance = 0.02f;
+static NSString *const kLiveStreamTestsDictObjectDetectorKey = @"object_detector";
+static NSString *const kLiveStreamTestsDictExpectationKey = @"expectation";
 
 #define AssertEqualErrors(error, expectedError)                                               \
   XCTAssertNotNil(error);                                                                     \
@@ -58,7 +60,10 @@ static const float scoreDifferenceTolerance = 0.02f;
   XCTAssertEqualWithAccuracy(boundingBox.size.height, expectedBoundingBox.size.height, \
                              pixelDifferenceTolerance, @"index i = %d", idx);
 
-@interface MPPObjectDetectorTests : XCTestCase
+@interface MPPObjectDetectorTests : XCTestCase <MPPObjectDetectorDelegate> {
+  NSDictionary *liveStreamSucceedsTestDict;
+  NSDictionary *outOfOrderTimestampTestDict;
+}
 @end
 
 @implementation MPPObjectDetectorTests
@@ -452,20 +457,17 @@ static const float scoreDifferenceTolerance = 0.02f;
     MPPObjectDetectorOptions *options = [self objectDetectorOptionsWithModelName:kModelName];
 
     options.runningMode = runningModesToTest[i];
-    options.completion =
+    options.objectDetectorDelegate = self;
-        ^(MPPObjectDetectionResult *result, NSInteger timestampInMilliseconds, NSError *error) {
-        };
 
-    [self
+    [self assertCreateObjectDetectorWithOptions:options
-        assertCreateObjectDetectorWithOptions:options
                          failsWithExpectedError:
-                           [NSError
+                             [NSError errorWithDomain:kExpectedErrorDomain
-                               errorWithDomain:kExpectedErrorDomain
                                                  code:MPPTasksErrorCodeInvalidArgumentError
                                              userInfo:@{
                                                NSLocalizedDescriptionKey :
-                                            @"The vision task is in image or video mode, a "
+                                                   @"The vision task is in image or video mode. "
-                                            @"user-defined result callback should not be provided."
+                                                   @"The delegate must not be"
+                                                   @"set in the task's options."
                                              }]];
   }
 }
@@ -481,8 +483,10 @@ static const float scoreDifferenceTolerance = 0.02f;
                                                code:MPPTasksErrorCodeInvalidArgumentError
                                            userInfo:@{
                                              NSLocalizedDescriptionKey :
-                                                 @"The vision task is in live stream mode, a "
+                                                 @"The vision task is in live stream mode. An "
-                                                 @"user-defined result callback must be provided."
+                                                 @"object must be set as the delegate of"
+                                                 @"the task in the its options to ensure "
+                                                 @"asynchronous delivery of results."
                                            }]];
 }
 
@@ -636,18 +640,11 @@ static const float scoreDifferenceTolerance = 0.02f;
       initWithDescription:@"detectWithOutOfOrderTimestampsAndLiveStream"];
   expectation.expectedFulfillmentCount = 1;
 
-  options.completion =
-      ^(MPPObjectDetectionResult *result, NSInteger timestampInMilliseconds, NSError *error) {
-        [self assertObjectDetectionResult:result
-                  isEqualToExpectedResult:
-                      [MPPObjectDetectorTests
-                          expectedDetectionResultForCatsAndDogsImageWithTimestampInMilliseconds:
-                              timestampInMilliseconds]
-                  expectedDetectionsCount:maxResults];
-        [expectation fulfill];
-      };
-
   MPPObjectDetector *objectDetector = [self objectDetectorWithOptionsSucceeds:options];
+  liveStreamSucceedsTestDict = {
+    kLiveStreamTestsDictObjectDetectorKey : objectDetector,
+    kLiveStreamTestsDictExpectationKey : expectation
+  };
 
   MPPImage *image = [self imageWithFileInfo:kCatsAndDogsImage];
 
@@ -693,19 +690,15 @@ static const float scoreDifferenceTolerance = 0.02f;
   expectation.expectedFulfillmentCount = iterationCount + 1;
   expectation.inverted = YES;
 
-  options.completion =
+  options.objectDetectorDelegate = self;
-      ^(MPPObjectDetectionResult *result, NSInteger timestampInMilliseconds, NSError *error) {
-        [self assertObjectDetectionResult:result
-                  isEqualToExpectedResult:
-                      [MPPObjectDetectorTests
-                          expectedDetectionResultForCatsAndDogsImageWithTimestampInMilliseconds:
-                              timestampInMilliseconds]
-                  expectedDetectionsCount:maxResults];
-        [expectation fulfill];
-      };
 
   MPPObjectDetector *objectDetector = [self objectDetectorWithOptionsSucceeds:options];
 
+  liveStreamSucceedsTestDict = {
+    kLiveStreamTestsDictObjectDetectorKey : objectDetector,
+    kLiveStreamTestsDictExpectationKey : expectation
+  };
+
   // TODO: Mimic initialization from CMSampleBuffer as live stream mode is most likely to be used
   // with the iOS camera. AVCaptureVideoDataOutput sample buffer delegates provide frames of type
   // `CMSampleBuffer`.
@@ -718,4 +711,23 @@ static const float scoreDifferenceTolerance = 0.02f;
   [self waitForExpectations:@[ expectation ] timeout:0.5];
 }
 
+- (void)objectDetector:(MPPObjectDetector *)objectDetector
+    didFinishObjectDetectionWithResult:(MPPObjectDetectionResult *)objectDetectionResult
+               timestampInMilliseconds:(NSInteger)timestampInMilliseconds
+                                 error:(NSError *)error {
+  NSInteger maxResults = 4;
+  [self assertObjectDetectionResult:result
+            isEqualToExpectedResult:
+                [MPPObjectDetectorTests
+                    expectedDetectionResultForCatsAndDogsImageWithTimestampInMilliseconds:
+                        timestampInMilliseconds]
+            expectedDetectionsCount:maxResults];
+
+  if (objectDetector == outOfOrderTimestampTestDict[kLiveStreamTestsDictObjectDetectorKey]) {
+    [outOfOrderTimestampTestDict[kLiveStreamTestsDictExpectationKey] fulfill];
+  } else if (objectDetector == liveStreamSucceedsTestDict[kLiveStreamTestsDictObjectDetectorKey]) {
+    [liveStreamSucceedsTestDict[kLiveStreamTestsDictExpectationKey] fulfill];
+  }
+}
+
 @end