Ensure variants are structs

1 files changed, 20 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java
index f93cea14..ac96ca3d 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java
@@ -4,6 +4,7 @@ import org.junit.jupiter.api.Test;
 import org.shedlang.compiler.ast.untyped.Untyped;
 import org.shedlang.compiler.ast.untyped.UntypedSumTypeDefinitionNode;
 import org.shedlang.compiler.typechecker.errors.CannotDefineSumTypeOutsideOfNamespace;
+import org.shedlang.compiler.typechecker.errors.VariantTypeIsNotStructError;
 import org.shedlang.compiler.types.NamespaceName;
 import org.shedlang.compiler.types.Types;
 import org.shedlang.compiler.util.P;
@@ -81,4 +82,23 @@ public class TypeCheckerSumTypeDefinitionTests {
             ))
         );
     }
+
+    @Test
+    public void whenVariantIsNotStructThenErrorIsThrown() {
+        var untyped = UntypedSumTypeDefinitionNode.builder()
+            .withName("ExampleSumType")
+            .addVariant(Untyped.typeLevelReference("String"))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterGlobal(P.map(
+                Map.entry("String", Types.metaType(Types.STRING))
+            ));
+
+        var error = assertThrows(
+            VariantTypeIsNotStructError.class,
+            () -> typeCheckNamespaceStatement(untyped, context)
+        );
+
+        assertThat(error.variantType(), equalTo(Types.STRING));
+    }
 }