feature: Coroutine Task Wrapper (#1064)

* feature: Coroutine Task Wrapper
- Add extension functions to wrap Task in coroutine
- Update libs

* feature: Coroutine Task Wrapper
- Suppress unused
- Correct logic for background threading

Author: phillwiggins

build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = "1.3.72"
+    ext.kotlin_version = "1.4.10"
     repositories {
         google()
         jcenter()

coroutines/README.md

@@ -72,6 +72,33 @@ launch { // Coroutine builder
 
 We can save, pinning and fetch parse objects use coroutines as well.
 
+## Task Wrapper
+Coroutine support can be provided as an extension method on any `Task`. For example:
+```kotlin
+suspend fun anonymousLogin() {
+    try {
+        val user = ParseAnonymousUtils.logInInBackground().suspendGet()
+        Timber.d("Logged in with user ${user.objectId}")
+    } catch (e: ParseException) {
+        Timber.e(e)
+    }
+}
+```
+Tasks with a Void results, ie. `Task<Void>` can be made into a `Completable`.
+For example:
+```kotlin
+suspend fun updateUserLastLogIn() {
+    val user = ParseUser.getCurrentUser()
+    user.put("lastLoggedIn", System.currentTimeMillis())
+    try {
+        user.saveInBackground().suspendRun()
+        Timber.d("user saved")
+    } catch (e: ParseException) {
+        Timber.e(it)
+    }
+}
+```
+
 ## Contributing
 When contributing to the `coroutines` module, please first consider if the extension function you are wanting to add would potentially be better suited in the main `parse` module. If it is something specific to Kotlin users or only useful in a Kotlin project, feel free to make a PR adding it to this module. Otherwise, consider adding the addition to the `parse` module itself, so that it is still usable in Java.
 

coroutines/build.gradle

@@ -29,7 +29,7 @@ android {
 }
 
 ext {
-    coroutinesVersion = "1.3.3"
+    coroutinesVersion = "1.3.9"
 }
 
 dependencies {

coroutines/src/main/java/com/parse/coroutines/ParseTaskExtensions.kt

@@ -0,0 +1,35 @@
+@file:JvmName("ParseTaskExtensions")
+@file:Suppress("unused")
+
+package com.parse.coroutines
+
+import com.parse.boltsinternal.Task
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
+import kotlin.coroutines.suspendCoroutine
+
+@Suppress("BlockingMethodInNonBlockingContext")
+suspend fun <T> Task<T>.suspendGet(dispatcher: CoroutineDispatcher = Dispatchers.IO) = withContext<T>(dispatcher) {
+    return@withContext suspendCoroutine { continuation ->
+        waitForCompletion()
+        if (isFaulted) {
+            continuation.resumeWithException(error)
+        }
+        continuation.resume(result)
+    }
+}
+
+@Suppress("BlockingMethodInNonBlockingContext")
+suspend fun Task<Void>.suspendRun(dispatcher: CoroutineDispatcher = Dispatchers.IO) = withContext<Unit>(dispatcher) {
+    return@withContext suspendCoroutine { continuation ->
+        waitForCompletion()
+        if (isFaulted) {
+            continuation.resumeWithException(error)
+        }
+        continuation.resume(Unit)
+    }
+}
+