Introduce variables for type params

1 files changed, 63 insertions, 2 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 91839f6..1de6cbf 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerStructDefinitionTests.java
@@ -18,7 +18,7 @@ import static org.zwobble.precisely.Matchers.*;
 
 public class TypeCheckerStructDefinitionTests {
     @Test
-    public void whenStructDefinitionHasNoTypeParamsThenNameIsBoundToType() {
+    public void whenStructDefinitionHasNoTypeParamsThenStructNameIsBoundToType() {
         var untyped = UntypedStructDefinitionNode.arbitrary()
             .withName("X")
             .build();
@@ -41,7 +41,7 @@ public class TypeCheckerStructDefinitionTests {
     }
 
     @Test
-    public void whenStructDefinitionHasTypeParamsThenNameIsBoundToTypeConstructor() {
+    public void whenStructDefinitionHasTypeParamsThenStructNameIsBoundToTypeConstructor() {
         var untyped = UntypedStructDefinitionNode.arbitrary()
             .withName("X")
             .withTypeParams(Optional.of(List.of(
@@ -160,6 +160,67 @@ public class TypeCheckerStructDefinitionTests {
     }
 
     @Test
+    public void whenStructDefinitionHasTypeParamsThenTypeParamsAreBoundWithinStructDefinition() {
+        var untyped = UntypedStructDefinitionNode.arbitrary()
+            .withName("X")
+            .withTypeParams(Optional.of(List.of(
+                UntypedTypeParamNode.arbitrary().withName("A").build(),
+                UntypedTypeParamNode.arbitrary().withName("B").build()
+            )))
+            .withFields(List.of(
+                UntypedStructFieldDefinitionNode.arbitrary()
+                    .withName("a")
+                    .withType(UntypedArb.typeLevelReference("A"))
+                    .build(),
+                UntypedStructFieldDefinitionNode.arbitrary()
+                    .withName("b")
+                    .withType(UntypedArb.typeLevelReference("B"))
+                    .build()
+            ))
+            .build();
+        var globalContext = TypeCheckerGlobalContext.initial();
+        var namespaceName = NamespaceName.of("a", "b");
+        var namespaceContext = globalContext.enterNamespace(namespaceName);
+
+        var typed = typeCheckNamespaceStatement(untyped, namespaceContext);
+
+        var expectedInnerType = new SimpleStructType(NamespaceName.of("a", "b"), "X");
+        assertThat(typed, instanceOf(
+            TypedStructDefinitionNode.class,
+            has(
+                "fields",
+                TypedStructDefinitionNode::fields,
+                isOptionalOf(isSequence(
+                    allOf(
+                        has("name", TypedStructFieldDefinitionNode::name, equalTo("a")),
+                        has("type", TypedStructFieldDefinitionNode::type, has(
+                            "value",
+                            TypedTypeLevelExpressionNode::value,
+                            equalTo(new TypeParam(expectedInnerType, "A"))
+                        ))
+                    ),
+                    allOf(
+                        has("name", TypedStructFieldDefinitionNode::name, equalTo("b")),
+                        has("type", TypedStructFieldDefinitionNode::type, has(
+                            "value",
+                            TypedTypeLevelExpressionNode::value,
+                            equalTo(new TypeParam(expectedInnerType, "B"))
+                        ))
+                    )
+                ))
+            )
+        ));
+        var typesInfo = globalContext.toTypesInfo();
+        assertThat(
+            typesInfo.fieldsOf(new SimpleStructType(namespaceName, "X")),
+            isOptionalOf(isSequence(
+                isField("a", new TypeParam(expectedInnerType, "A")),
+                isField("b", new TypeParam(expectedInnerType, "B"))
+            ))
+        );
+    }
+
+    @Test
     public void structCanUseTypeDefinedLater() {
         var int32Type = SimpleNativeType.builtin("Int32");
         var namespaceName = NamespaceName.of("a", "b");