testsuite: test "no intersection" error message

test the error message for non-intersecting polymorphic variant types.
ocaml · Feb 26, 2019 · 70a9134 · 70a9134
1 parent ce95fa4
commit 70a9134
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/testsuite/tests/typing-misc/polyvars.ml b/testsuite/tests/typing-misc/polyvars.ml
@@ -154,3 +154,13 @@ Here is an example of a case that is not matched:
 (`AnyOtherTag', `AnyOtherTag'')
 val f : [> `AnyOtherTag ] * [> `AnyOtherTag | `AnyOtherTag' ] -> int = <fun>
 |}]
+
+let x:(([`A] as 'a)* ([`B] as 'a)) = [`A]
+[%%expect {|
+Line 1, characters 22-32:
+1 | let x:(([`A] as 'a)* ([`B] as 'a)) = [`A]
+                          ^^^^^^^^^^
+Error: This alias is bound to type [ `B ] but is used as an instance of type
+         [ `A ]
+       These two variant types have no intersection
+|}]