multisync now allows tuples in return type (#21074)

* Add test case

* Use .toStrLit() on param node first

This means that more complex types are fully rendered

lib/pure/asyncmacro.nim

@@ -286,8 +286,8 @@ macro async*(prc: untyped): untyped =
 proc splitParamType(paramType: NimNode, async: bool): NimNode =
   result = paramType
   if paramType.kind == nnkInfix and paramType[0].strVal in ["|", "or"]:
-    let firstAsync = "async" in paramType[1].strVal.normalize
-    let secondAsync = "async" in paramType[2].strVal.normalize
+    let firstAsync = "async" in paramType[1].toStrLit().strVal.normalize
+    let secondAsync = "async" in paramType[2].toStrLit().strVal.normalize
 
     if firstAsync:
       result = paramType[if async: 1 else: 2]

tests/async/t20111.nim

@@ -0,0 +1,19 @@
+discard """
+  action: "run"
+"""
+import asyncdispatch
+type
+    Sync = object
+    Async = object
+    SyncRes = (Sync, string)
+    AsyncRes = (Async, string)
+
+proc foo(val: Sync | Async): Future[(Async, string) | (Sync, string)] {.multisync.} =
+    return (val, "hello")
+
+let
+  myAsync = Async()
+  mySync = Sync()
+
+doAssert typeof(waitFor foo(myAsync)) is AsyncRes
+doAssert typeof(foo(mySync)) is SyncRes