Type check return type of function type

2 files changed, 48 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java b/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
index c5a27329..112b2f02 100644
--- a/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/typed/TypedNodeMatchers.java
@@ -125,6 +125,15 @@ public class TypedNodeMatchers {
         );
     }
 
+    public static Matcher<TypedTypeLevelExpressionNode<?>> isTypedFunctionTypeNode(
+        Matcher<FunctionType> value
+    ) {
+        return instanceOf(
+            TypedFunctionTypeNode.class,
+            has("value", x -> x.value(), value)
+        );
+    }
+
     public static Matcher<TypedExpressionNode> isTypedIfNode(
         Matcher<Iterable<? extends TypedConditionalBranchNode>> conditionalBranches,
         Matcher<TypedBlockNode> elseBody
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionTypeTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionTypeTests.java
new file mode 100644
index 00000000..608e3caf
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerFunctionTypeTests.java
@@ -0,0 +1,39 @@
+package org.shedlang.compiler.typechecker;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.untyped.Untyped;
+import org.shedlang.compiler.ast.untyped.UntypedFunctionTypeNode;
+import org.shedlang.compiler.typechecker.typesets.TypeSets;
+import org.shedlang.compiler.types.FunctionType;
+import org.shedlang.compiler.types.Types;
+import org.shedlang.compiler.util.P;
+
+import java.util.Map;
+
+import static org.shedlang.compiler.ast.typed.TypedNodeMatchers.isTypedFunctionTypeNode;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+
+public class TypeCheckerFunctionTypeTests {
+    @Test
+    public void returnTypeIsTypeChecked() {
+        var untyped = UntypedFunctionTypeNode.builder()
+            .withReturnType(Untyped.typeLevelReference("String"))
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .enterGlobal(P.map(
+                Map.entry("String", Types.metaType(Types.STRING))
+            ));
+
+        var typed = TypeChecker.typeCheckTypeLevelExpression(TypeSets.META_TYPE, untyped, context);
+
+        assertThat(
+            typed,
+            isTypedFunctionTypeNode(equalTo(
+                FunctionType.builder()
+                    .withReturnType(Types.STRING)
+                    .build()
+            ))
+        );
+    }
+}