Disable subtyping for function types with type level params

1 files changed, 17 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java
index ca3008f3..9207024f 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerIsSubTypeTests.java
@@ -320,4 +320,21 @@ public class TypeCheckerIsSubTypeTests {
         assertThat(isSubType(functionType2, functionType1, context), equalTo(true));
         assertThat(isSubType(functionType1, functionType2, context), equalTo(false));
     }
+
+    @Test
+    public void whenFunctionHasTypeLevelParamsThenOtherFunctionsAreNotSupertypesNorSubtypes() {
+        var functionType1 = FunctionType.builder()
+            .withTypeLevelParams(List.of(
+                TypeParam.forStructType(Types.struct(NamespaceName.of("Example"), "Box"), "T")
+            ))
+            .withReturnType(Types.UNIT)
+            .build();
+        var functionType2 = FunctionType.builder()
+            .withReturnType(Types.UNIT)
+            .build();
+        var context = TypeCheckerContext.EMPTY;
+
+        assertThat(isSubType(functionType2, functionType1, context), equalTo(false));
+        assertThat(isSubType(functionType1, functionType2, context), equalTo(false));
+    }
 }