weak jobs workaround

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 0.4.33
 
+* `Coroutines`
+    * Add `WeakJob` workaround:
+        * `CoroutineScope#`
+
 ## 0.4.32
 
 * `Versions`:

coroutines/src/commonMain/kotlin/dev/inmo/micro_utils/coroutines/WeakJob.kt

@@ -0,0 +1,31 @@
+package dev.inmo.micro_utils.coroutines
+
+import kotlinx.coroutines.*
+import kotlin.coroutines.CoroutineContext
+import kotlin.coroutines.EmptyCoroutineContext
+
+fun CoroutineScope.createWeakSubScope() = CoroutineScope(coroutineContext.minusKey(Job)).also { newScope ->
+    coroutineContext.job.invokeOnCompletion { newScope.cancel() }
+}
+
+fun CoroutineScope.weakLaunch(
+    context: CoroutineContext = EmptyCoroutineContext,
+    start: CoroutineStart = CoroutineStart.DEFAULT,
+    block: suspend CoroutineScope.() -> Unit
+): Job {
+    val scope = createWeakSubScope()
+    val job = scope.launch(context, start, block)
+    job.invokeOnCompletion { scope.cancel() }
+    return job
+}
+
+fun <T> CoroutineScope.weakAsync(
+    context: CoroutineContext = EmptyCoroutineContext,
+    start: CoroutineStart = CoroutineStart.DEFAULT,
+    block: suspend CoroutineScope.() -> T
+): Deferred<T> {
+    val scope = createWeakSubScope()
+    val deferred = scope.async(context, start, block)
+    deferred.invokeOnCompletion { scope.cancel() }
+    return deferred
+}

coroutines/src/jvmTest/kotlin/dev/inmo/micro_utils/coroutines/WeakJob.kt

@@ -0,0 +1,40 @@
+package dev.inmo.micro_utils.coroutines
+
+import kotlinx.coroutines.*
+import org.junit.Test
+
+class WeakJob {
+    @Test
+    fun `test that weak jobs works correctly`() {
+        val scope = CoroutineScope(Dispatchers.Default)
+        lateinit var weakLaunchJob: Job
+        lateinit var weakAsyncJob: Job
+        scope.launchSynchronously {
+            val completeDeferred = Job()
+            coroutineScope {
+                weakLaunchJob = weakLaunch {
+                    while (isActive) {
+                        delay(100L)
+                    }
+                }
+                weakAsyncJob = weakAsync {
+                    while (isActive) {
+                        delay(100L)
+                    }
+                }
+
+                coroutineContext.job.invokeOnCompletion {
+                    scope.launch {
+                        delay(1000L)
+                        completeDeferred.complete()
+                    }
+                }
+                launch { delay(1000L); cancel() }
+            }
+            completeDeferred.join()
+        }
+
+        assert(!weakLaunchJob.isActive)
+        assert(!weakAsyncJob.isActive)
+    }
+}