refactor illegal iterator assignment detection (#12212)

* refactor illegal iterator assignment detection

* delete crappy test

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/errmsgs/ttypeAllowed.nim b/tests/errmsgs/ttypeAllowed.nim
new file mode 100644
index 000000000..a5b335faa
--- /dev/null
+++ b/tests/errmsgs/ttypeAllowed.nim
@@ -0,0 +1,28 @@
+discard """
+cmd: "nim check $file"
+errmsg: ""
+nimout: '''
+ttypeAllowed.nim(13, 5) Error: invalid type: 'iterator (a: int, b: int, step: Positive): int{.inline, noSideEffect, gcsafe, locks: 0.}' for let
+ttypeAllowed.nim(17, 7) Error: invalid type for const: iterator (a: int, b: int, step: Positive): int{.inline, noSideEffect, gcsafe, locks: 0.}
+ttypeAllowed.nim(21, 5) Error: invalid type: 'iterator (a: int, b: int, step: Positive): int{.inline, noSideEffect, gcsafe, locks: 0.}' for var
+ttypeAllowed.nim(26, 10) Error: invalid type: 'iterator (a: int, b: int, step: Positive): int{.inline, noSideEffect, gcsafe, locks: 0.}' for result
+'''
+"""
+
+
+let f1 = case true
+  of true:  countup[int]
+  of false: countdown[int]
+
+const f2 = case true
+  of true:  countup[int]
+  of false: countdown[int]
+
+var f3 = case true
+  of true:  countup[int]
+  of false: countdown[int]
+
+proc foobar(): auto =
+  result = case true
+    of true:  countup[int]
+    of false: countdown[int]