Add solution for Flow exception handling exercise

Author: LukasLechnerDev

app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase3/FlowUseCase3ViewModel.kt

@@ -3,6 +3,7 @@ package com.lukaslechner.coroutineusecasesonandroid.usecases.flow.usecase3
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.asLiveData
 import com.lukaslechner.coroutineusecasesonandroid.base.BaseViewModel
+import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onCompletion
 import kotlinx.coroutines.flow.onStart
@@ -37,5 +38,9 @@ class FlowUseCase3ViewModel(
         .onCompletion {
             Timber.tag("Flow").d("Flow has completed.")
         }
+        .catch { throwable ->
+            Timber.tag("Flow").d("Enter catch operator with $throwable")
+            emit(UiState.Error("something went wrong"))
+        }
         .asLiveData()
 }

app/src/main/java/com/lukaslechner/coroutineusecasesonandroid/usecases/flow/usecase3/StockPriceDataSource.kt

@@ -5,6 +5,8 @@ import com.lukaslechner.coroutineusecasesonandroid.usecases.flow.mock.Stock
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.retry
+import retrofit2.HttpException
 import timber.log.Timber
 
 interface StockPriceDataSource {
@@ -20,5 +22,15 @@ class NetworkStockPriceDataSource(mockApi: FlowMockApi) : StockPriceDataSource {
             emit(currentStockList)
             delay(5_000)
         }
+    }.retry { cause ->
+        Timber.tag("Flow").d("Enter retry operator with $cause")
+
+        val shouldRetry = cause is HttpException
+
+        if (shouldRetry) {
+            delay(5_000)
+        }
+
+        shouldRetry
     }
 }