InterruptedException and IOException now excluded exceptions to alert on (#791)

* InterruptedException and IOException now excluded exceptions to alert on

* Change IOException to InterruptedIOException and permit crash on DEBUG

* Remove UndeliverableException from alerting handler; handled elsewhere

Author: CDRussell

app/src/main/java/com/duckduckgo/app/global/AlertingUncaughtExceptionHandler.kt

@@ -16,28 +16,60 @@
 
 package com.duckduckgo.app.global
 
+import com.duckduckgo.app.browser.BuildConfig
 import com.duckduckgo.app.global.exception.UncaughtExceptionRepository
 import com.duckduckgo.app.global.exception.UncaughtExceptionSource
 import com.duckduckgo.app.statistics.store.OfflinePixelCountDataStore
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.launch
+import java.io.InterruptedIOException
 
 class AlertingUncaughtExceptionHandler(
     private val originalHandler: Thread.UncaughtExceptionHandler,
     private val offlinePixelCountDataStore: OfflinePixelCountDataStore,
     private val uncaughtExceptionRepository: UncaughtExceptionRepository
 ) : Thread.UncaughtExceptionHandler {
 
-    override fun uncaughtException(t: Thread?, originalException: Throwable?) {
+    override fun uncaughtException(thread: Thread?, originalException: Throwable?) {
 
+        if (shouldRecordExceptionAndCrashApp(originalException)) {
+            recordExceptionAndAllowCrash(thread, originalException)
+            return
+        }
+
+        if (shouldCrashApp()) {
+            originalHandler.uncaughtException(thread, originalException)
+        }
+
+    }
+
+    /**
+     * Some exceptions happen due to lifecycle issues, such as our sync service being forced to stop.
+     * In such cases, we don't need to alert about the exception as they are exceptions essentially signalling that work was interrupted.
+     * Examples of this would be if the internet was lost during the sync,
+     * or when two or more sync operations are scheduled to run at the same time; one would run and the rest would be interrupted.
+     */
+    private fun shouldRecordExceptionAndCrashApp(exception: Throwable?): Boolean {
+        return when (exception) {
+            is InterruptedException, is InterruptedIOException -> false
+            else -> true
+        }
+    }
+
+    /**
+     * If the exception is one we don't report on, we still want to see a crash when we're in DEBUG builds for safety we aren't ignoring important issues
+     */
+    private fun shouldCrashApp(): Boolean = BuildConfig.DEBUG
+
+    private fun recordExceptionAndAllowCrash(thread: Thread?, originalException: Throwable?) {
         GlobalScope.launch(Dispatchers.IO + NonCancellable) {
             uncaughtExceptionRepository.recordUncaughtException(originalException, UncaughtExceptionSource.GLOBAL)
             offlinePixelCountDataStore.applicationCrashCount += 1
 
             // wait until the exception has been fully processed before propagating exception
-            originalHandler.uncaughtException(t, originalException)
+            originalHandler.uncaughtException(thread, originalException)
         }
     }
 }