Treat variant as subtype of sum

1 files changed, 38 insertions, 2 deletions

diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java
index 35779fe..e2b43d0 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSubtypingTests.java
@@ -1,7 +1,12 @@
 package org.zwobble.hobgoblin.compiler.typechecker;
 
 import org.junit.jupiter.api.Test;
+import org.zwobble.hobgoblin.compiler.types.NamespaceName;
 import org.zwobble.hobgoblin.compiler.types.SimpleNativeType;
+import org.zwobble.hobgoblin.compiler.types.StructType;
+import org.zwobble.hobgoblin.compiler.types.SumType;
+
+import java.util.List;
 
 import static org.zwobble.hobgoblin.compiler.typechecker.TypeCheckerSubtyping.isSubtype;
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -13,7 +18,7 @@ public class TypeCheckerSubtypingTests {
         var nativeType1 = SimpleNativeType.builtin("Int32");
         var nativeType2 = SimpleNativeType.builtin("Int32");
 
-        var isSubtype = isSubtype(nativeType1, nativeType2);
+        var isSubtype = isSubtype(nativeType1, nativeType2, TypesInfo.EMPTY);
 
         assertThat(isSubtype, equalTo(true));
     }
@@ -23,7 +28,38 @@ public class TypeCheckerSubtypingTests {
         var nativeType1 = SimpleNativeType.builtin("Int32");
         var nativeType2 = SimpleNativeType.builtin("Int64");
 
-        var isSubtype = isSubtype(nativeType1, nativeType2);
+        var isSubtype = isSubtype(nativeType1, nativeType2, TypesInfo.EMPTY);
+
+        assertThat(isSubtype, equalTo(false));
+    }
+
+    @Test
+    public void variantIsSubtypeOfSumType() {
+        var variantType1 = new StructType(NamespaceName.of(), "Rectangle");
+        var variantType2 = new StructType(NamespaceName.of(), "Circle");
+        var sumType = new SumType(NamespaceName.of(), "Shape");
+        var typesInfo = TypesInfoInMemory.empty();
+        typesInfo.defineSumType(sumType, List.of(variantType1, variantType2), List.of());
+
+        var isSubtype = isSubtype(variantType1, sumType, typesInfo);
+
+        assertThat(isSubtype, equalTo(true));
+    }
+
+    @Test
+    public void variantIsNotSubtypeOfUnrelatedSumType() {
+        var typesInfo = TypesInfoInMemory.empty();
+
+        var variantType1 = new StructType(NamespaceName.of(), "Rectangle");
+        var variantType2 = new StructType(NamespaceName.of(), "Circle");
+        var sumType = new SumType(NamespaceName.of(), "Shape");
+        typesInfo.defineSumType(sumType, List.of(variantType1, variantType2), List.of());
+
+        var otherSumType = new SumType(NamespaceName.of(), "Shape3D");
+        var otherVariantType = new StructType(NamespaceName.of(), "Cube");
+        typesInfo.defineSumType(sumType, List.of(otherVariantType), List.of());
+
+        var isSubtype = isSubtype(variantType1, otherSumType, typesInfo);
 
         assertThat(isSubtype, equalTo(false));
     }