[MS-1243] Controlling the matcher execution with the isMatcherRunning flag

feature/matcher/src/main/java/com/simprints/matcher/screen/MatchViewModel.kt

@@ -33,6 +33,8 @@ internal class MatchViewModel @Inject constructor(
     private val configManager: ConfigManager,
     private val timeHelper: TimeHelper,
 ) : ViewModel() {
+    var isMatcherRunning = false
+        private set
     var isInitialized = false
         private set
     private var candidatesLoaded = 0
@@ -48,6 +50,8 @@ internal class MatchViewModel @Inject constructor(
     private val _matchResponse = MutableLiveData<LiveDataEventWithContent<Serializable>>()
 
     fun setupMatch(params: MatchParams) = viewModelScope.launch {
+        if (isMatcherRunning) return@launch
+        isMatcherRunning = true
         isInitialized = true
         val startTime = timeHelper.now()
 

feature/matcher/src/test/java/com/simprints/matcher/screen/MatchViewModelTest.kt

@@ -355,6 +355,43 @@ internal class MatchViewModelTest {
         )
     }
 
+    @Test
+    fun `setupMatch does not continue when isMatcherRunning is true`() = runTest {
+        // Seting up a matcher runs in background
+        coEvery { faceMatcherUseCase.invoke(any(), any()) } returns flow {
+            emit(MatcherUseCase.MatcherState.LoadingStarted(1))
+            emit(MatcherUseCase.MatcherState.CandidateLoaded)
+            emit(
+                MatcherUseCase.MatcherState.Success(
+                    matchResultItems = listOf(FaceMatchResult.Item("1", 90f)),
+                    totalCandidates = 1,
+                    matcherName = MATCHER_NAME,
+                    matchBatches = emptyList(),
+                ),
+            )
+        }
+        coJustRun { saveMatchEvent.invoke(any(), any(), any(), any(), any(), any(), any()) }
+
+        val states = viewModel.matchState.test()
+        val matchParams = MatchParams(
+            probeReferenceId = "referenceId",
+            probeFaceSamples = listOf(getFaceSample()),
+            faceSDK = FaceConfiguration.BioSdk.RANK_ONE,
+            flowType = FlowType.ENROL,
+            queryForCandidates = mockk {},
+            biometricDataSource = BiometricDataSource.Simprints,
+        )
+
+        viewModel.setupMatch(matchParams)
+        assertThat(viewModel.isMatcherRunning).isTrue()
+        viewModel.setupMatch(matchParams)
+        advanceUntilIdle()
+
+        coVerify(exactly = 1) { faceMatcherUseCase.invoke(any(), any()) }
+        // Checking that no new states were emitted. History = (NotStarted, LoadingCandidates LoadingCandidates, Finished)
+        assertThat(states.valueHistory()).hasSize(4)
+    }
+
     private fun getFaceSample(): MatchParams.FaceSample = MatchParams.FaceSample(UUID.randomUUID().toString(), Random.nextBytes(20))
 
     private fun getFingerprintSample(): MatchParams.FingerprintSample = MatchParams.FingerprintSample(