[K/JS] Fix coroutines on ES2015 generators when there is not a GeneratorCoroutine was provided as a continuation ^KTOR-6882 Fixed

Author: JSMonk

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/JsIntrinsicTransformers.kt

@@ -284,6 +284,16 @@ class JsIntrinsicTransformers(backendContext: JsIrBackendContext) {
                 val backingField = context.getNameForField(intrinsics.void.owner.backingField!!)
                 JsNameRef(backingField)
             }
+
+            add(intrinsics.suspendOrReturnFunctionSymbol) { call, context ->
+                val (generatorCall, continuation) = translateCallArguments(call, context)
+                val jsInvokeFunName = context.getNameForStaticFunction(call.symbol.owner)
+                val VOID = context.getNameForField(intrinsics.void.owner.backingField!!)
+                val generatorBindCall = (generatorCall as JsInvocation).let {
+                    JsInvocation(JsNameRef(Namer.BIND_FUNCTION, it.qualifier), listOf(JsNameRef(VOID)) + it.arguments.dropLast(1))
+                }
+                JsInvocation(JsNameRef(jsInvokeFunName), generatorBindCall, continuation)
+            }
         }
     }
 

libraries/stdlib/js/src/kotlin/coroutines/intrinsics/IntrinsicsJs.kt

@@ -281,16 +281,18 @@ internal fun <R, T, P> (suspend R.(P) -> T).createCoroutineUninterceptedGenerato
     }
 
 
-internal fun suspendOrReturn(value: Any?, continuation: Continuation<Any?>): Any? {
-    if (!isGeneratorSuspendStep(value)) return value
+internal fun suspendOrReturn(generator: (continuation: Continuation<Any?>) -> dynamic, continuation: Continuation<Any?>): Any? {
+    val generatorCoroutineImpl = if (continuation.asDynamic().constructor === GeneratorCoroutineImpl::class.js) {
+        continuation.unsafeCast<GeneratorCoroutineImpl>()
+    } else {
+        GeneratorCoroutineImpl(continuation)
+    }
 
-    val iterator = value.unsafeCast<JsIterator<Any?>>()
+    val value = generator(generatorCoroutineImpl)
 
-    if (continuation.asDynamic().constructor !== GeneratorCoroutineImpl::class.js) {
-        return iterator.next().value
-    }
+    if (!isGeneratorSuspendStep(value)) return value
 
-    val generatorCoroutineImpl = continuation.unsafeCast<GeneratorCoroutineImpl>()
+    val iterator = value.unsafeCast<JsIterator<Any?>>()
 
     generatorCoroutineImpl.addNewIterator(iterator)
     try {