fixes #22210; transform return future in try/finally properly (#22249)

* wip; fixes #22210; transform return future in try/finally properly

* add a test case for #22210

* minor

* inserts a needsCompletion flag

* uses copyNimNode

2 files changed, 114 insertions, 0 deletions

diff --git a/tests/async/t22210.nim b/tests/async/t22210.nim
new file mode 100644
index 000000000..fcf939472
--- /dev/null
+++ b/tests/async/t22210.nim
@@ -0,0 +1,41 @@
+discard """
+output: '''
+stage 1
+stage 2
+stage 3
+(status: 200, data: "SOMEDATA")
+'''
+"""
+
+import std/asyncdispatch
+
+
+# bug #22210
+type
+  ClientResponse = object
+    status*: int
+    data*: string
+
+proc subFoo1(): Future[int] {.async.} =
+  await sleepAsync(100)
+  return 200
+
+proc subFoo2(): Future[string] {.async.} =
+  await sleepAsync(100)
+  return "SOMEDATA"
+
+proc testFoo(): Future[ClientResponse] {.async.} =
+  try:
+    let status = await subFoo1()
+    doAssert(status == 200)
+    let data = await subFoo2()
+    return ClientResponse(status: status, data: data)
+  finally:
+    echo "stage 1"
+    await sleepAsync(100)
+    echo "stage 2"
+    await sleepAsync(200)
+    echo "stage 3"
+
+when isMainModule:
+  echo waitFor testFoo()
\ No newline at end of file
diff --git a/tests/async/t22210_2.nim b/tests/async/t22210_2.nim
new file mode 100644
index 000000000..9db664a32
--- /dev/null
+++ b/tests/async/t22210_2.nim
@@ -0,0 +1,73 @@
+import std/asyncdispatch
+
+
+# bug #22210
+type
+  ClientResponse = object
+    status*: int
+    data*: string
+
+proc subFoo1(): Future[int] {.async.} =
+  await sleepAsync(100)
+  return 200
+
+proc subFoo2(): Future[string] {.async.} =
+  await sleepAsync(100)
+  return "SOMEDATA"
+
+
+proc testFoo2(): Future[ClientResponse] {.async.} =
+  var flag = 0
+  try:
+    let status = await subFoo1()
+    doAssert(status == 200)
+    let data = await subFoo2()
+    result = ClientResponse(status: status, data: data)
+  finally:
+    inc flag
+    await sleepAsync(100)
+    inc flag
+    await sleepAsync(200)
+    inc flag
+  doAssert flag == 3
+
+discard waitFor testFoo2()
+
+proc testFoo3(): Future[ClientResponse] {.async.} =
+  var flag = 0
+  try:
+    let status = await subFoo1()
+    doAssert(status == 200)
+    let data = await subFoo2()
+    if false:
+      return ClientResponse(status: status, data: data)
+  finally:
+    inc flag
+    await sleepAsync(100)
+    inc flag
+    await sleepAsync(200)
+    inc flag
+  doAssert flag == 3
+
+discard waitFor testFoo3()
+
+
+proc testFoo4(): Future[ClientResponse] {.async.} =
+  var flag = 0
+  try:
+    let status = await subFoo1()
+    doAssert(status == 200)
+    let data = await subFoo2()
+    if status == 200:
+      return ClientResponse(status: status, data: data)
+    else:
+      return ClientResponse()
+  finally:
+    inc flag
+    await sleepAsync(100)
+    inc flag
+    await sleepAsync(200)
+    inc flag
+  doAssert flag == 3
+
+discard waitFor testFoo4()