test: Fix ANRTrackerTests.clearDirectlyAfterStart (#4773)

The tests testClearDirectlyAfterStart,
testClearDirectlyAfterStart_FullyBlocking_NotReported
sometimes failed with the started and finished invocations being greater
than 1. This is fixed now by asserting the number of starts matches
the number of finish invocations.

Author: philipphofmann

Tests/SentryTests/Integrations/ANR/SentryANRTrackerV1Tests.swift

@@ -189,7 +189,7 @@ class SentryANRTrackerV1Tests: XCTestCase, SentryANRTrackerDelegate {
         wait(for: [anrDetectedExpectation, anrStoppedExpectation], timeout: 0.0)
     }
 
-    func testClearDirectlyAfterStart() {
+    func testClearDirectlyAfterStart_FinishesThread() {
         anrDetectedExpectation.isInverted = true
 
         let invocations = 10
@@ -201,8 +201,9 @@ class SentryANRTrackerV1Tests: XCTestCase, SentryANRTrackerDelegate {
         wait(for: [anrDetectedExpectation, anrStoppedExpectation], timeout: 1)
 
         XCTAssertEqual(0, fixture.threadWrapper.threads.count)
-        XCTAssertEqual(1, fixture.threadWrapper.threadStartedInvocations.count)
-        XCTAssertEqual(1, fixture.threadWrapper.threadFinishedInvocations.count)
+        // As it can take a while until a new thread is started, the thread tracker may start
+        // and finish multiple times. Most importantly, the code covers every start with one finish.
+        XCTAssertEqual(fixture.threadWrapper.threadStartedInvocations.count, fixture.threadWrapper.threadFinishedInvocations.count, "The number of started and finished threads should be equal, otherwise the ANR tracker could run.")
     }
 
     // swiftlint:disable test_case_accessibility

Tests/SentryTests/Integrations/ANR/SentryANRTrackerV2Tests.swift

@@ -403,9 +403,10 @@ class SentryANRTrackerV2Tests: XCTestCase {
 
         wait(for: [listener.anrDetectedExpectation, listener.anrStoppedExpectation], timeout: self.waitTimeout)
 
-        XCTAssertEqual(0, threadWrapper.threads.count)
-        XCTAssertEqual(1, threadWrapper.threadStartedInvocations.count)
-        XCTAssertEqual(1, threadWrapper.threadFinishedInvocations.count)
+        XCTAssertEqual(0, threadWrapper.threads.count)        
+        // As it can take a while until a new thread is started, the thread tracker may start
+        // and finish multiple times. Most importantly, the code covers every start with one finish.
+        XCTAssertEqual(threadWrapper.threadStartedInvocations.count, threadWrapper.threadFinishedInvocations.count, "The number of started and finished threads should be equal, otherwise the ANR tracker could run.")
     }
 
     func testNoFrameDelayData_FullyBlocking_NotReported() throws {