Check field presence for sum variants

2 files changed, 70 insertions, 8 deletions

diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java
index f45b215..81bf9b8 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java
@@ -5,17 +5,12 @@ import org.zwobble.hobgoblin.compiler.ast.typed.TypedNamespaceNode;
 import org.zwobble.hobgoblin.compiler.ast.typed.TypedStructDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.typed.TypedStructFieldDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.typed.TypedTypeLevelExpressionNode;
-import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedArb;
-import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedNamespaceNode;
-import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedStructDefinitionNode;
-import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedStructFieldDefinitionNode;
-import org.zwobble.hobgoblin.compiler.types.Field;
-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.ast.untyped.*;
+import org.zwobble.hobgoblin.compiler.types.*;
 
 import java.util.List;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.zwobble.hobgoblin.compiler.typechecker.TypeCheckerTesting.typeCheckNamespaceStatement;
 import static org.zwobble.precisely.AssertThat.assertThat;
 import static org.zwobble.precisely.Matchers.*;
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSumDefinitionTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSumDefinitionTests.java
index 57c40f5..36a4647 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSumDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerSumDefinitionTests.java
@@ -10,6 +10,7 @@ import org.zwobble.hobgoblin.compiler.types.*;
 
 import java.util.List;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.zwobble.hobgoblin.compiler.typechecker.TypeCheckerTesting.typeCheckNamespaceStatement;
 import static org.zwobble.precisely.AssertThat.assertThat;
 import static org.zwobble.precisely.Matchers.*;
@@ -130,4 +131,70 @@ public class TypeCheckerSumDefinitionTests {
             )
         ));
     }
+
+    @Test
+    public void givenVariantTypeIsDefinedFirstWhenVariantTypeIsMissingFieldThenErrorIsThrown() {
+        var int32Type = SimpleNativeType.builtin("Int32");
+        var untyped = UntypedSumDefinitionNode.arbitrary()
+            .withName("Shape")
+            .withVariants(List.of(
+                UntypedSumVariantDefinitionNode.arbitrary()
+                    .withType(UntypedTypeLevelReferenceNode.arbitrary().withName("Square"))
+                    .build()
+            ))
+            .withFields(List.of(
+                UntypedStructFieldDefinitionNode.arbitrary()
+                    .withName("area")
+                    .withType(UntypedTypeLevelReferenceNode.arbitrary().withName("Int32"))
+                    .build()
+            ))
+            .build();
+        var globalContext = TypeCheckerGlobalContext.initial();
+        globalContext.addNativeType(int32Type);
+        var namespaceName = NamespaceName.of("a", "b");
+        var namespaceContext = globalContext
+            .enterNamespace(namespaceName);
+        var variantType = new StructType(namespaceName, "Square");
+        namespaceContext.declare("Square", new TypeLevelValueType(variantType));
+        namespaceContext.defineStructType(variantType, List.of());
+
+        var error = assertThrows(
+            SubtypeIsMissingFieldError.class,
+            () -> typeCheckNamespaceStatement(untyped, namespaceContext)
+        );
+
+        assertThat(error.supertype(), equalTo(new SumType(namespaceName, "Shape")));
+        assertThat(error.subtype(), equalTo(variantType));
+        assertThat(error.fieldName(), equalTo("area"));
+    }
+
+    @Test
+    public void givenSumTypeIsDefinedFirstWhenVariantTypeIsMissingFieldThenErrorIsThrown() {
+        var int32Type = SimpleNativeType.builtin("Int32");
+        var untyped = UntypedStructDefinitionNode.arbitrary()
+            .withName("Square")
+            .build();
+        var globalContext = TypeCheckerGlobalContext.initial();
+        globalContext.addNativeType(int32Type);
+        var namespaceName = NamespaceName.of("a", "b");
+        var namespaceContext = globalContext
+            .enterNamespace(namespaceName);
+        var sumType = new SumType(namespaceName, "Shape");
+        var variantType = new StructType(namespaceName, "Square");
+        namespaceContext.declare("Sum", new TypeLevelValueType(sumType));
+        namespaceContext.defineSumType(
+            sumType,
+            List.of(variantType),
+            List.of(new Field("area", int32Type))
+        );
+
+        var error = assertThrows(
+            SubtypeIsMissingFieldError.class,
+            () -> typeCheckNamespaceStatement(untyped, namespaceContext)
+        );
+
+        assertThat(error.supertype(), equalTo(sumType));
+        assertThat(error.subtype(), equalTo(variantType));
+        assertThat(error.fieldName(), equalTo("area"));
+    }
 }