Declare sum types

2 files changed, 74 insertions, 11 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerStructDefinitionTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerStructDefinitionTests.java
index 0e27584a..5d53301d 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerStructDefinitionTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerStructDefinitionTests.java
@@ -35,7 +35,7 @@ public class TypeCheckerStructDefinitionTests {
     }
 
     @Test
-    public void canTypeCheckStructDefinitionWithNoFields() {
+    public void typeIsAddedToEnvironment() {
         var untyped = UntypedStructDefinitionNode.builder()
             .withName("ExampleStruct")
             .build();
@@ -44,15 +44,16 @@ public class TypeCheckerStructDefinitionTests {
         var typed = typeCheckNamespaceStatement(untyped, context);
 
         assertThat(
-            typed.value(),
-            isTypedStructDefinitionNode()
-                .withType(isStructType(NAMESPACE_NAME, "ExampleStruct"))
-                .withFields(isSequence())
+            typed.context().compileTimeLookup("ExampleStruct"),
+            isOptionalOf(equalTo(Variable.defined(
+                Types.metaType(Types.struct(NAMESPACE_NAME, "ExampleStruct")),
+                VariableType.CONSTANT
+            )))
         );
     }
 
     @Test
-    public void typeIsAddedToEnvironment() {
+    public void canTypeCheckStructDefinitionWithNoFields() {
         var untyped = UntypedStructDefinitionNode.builder()
             .withName("ExampleStruct")
             .build();
@@ -61,11 +62,10 @@ public class TypeCheckerStructDefinitionTests {
         var typed = typeCheckNamespaceStatement(untyped, context);
 
         assertThat(
-            typed.context().compileTimeLookup("ExampleStruct"),
-            isOptionalOf(equalTo(Variable.defined(
-                Types.metaType(Types.struct(NAMESPACE_NAME, "ExampleStruct")),
-                VariableType.CONSTANT
-            )))
+            typed.value(),
+            isTypedStructDefinitionNode()
+                .withType(isStructType(NAMESPACE_NAME, "ExampleStruct"))
+                .withFields(isSequence())
         );
     }
 
diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java
new file mode 100644
index 00000000..167a2477
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerSumTypeDefinitionTests.java
@@ -0,0 +1,63 @@
+package org.shedlang.compiler.typechecker;
+
+import org.junit.jupiter.api.Test;
+import org.shedlang.compiler.ast.typed.TypedNamespaceStatementNode;
+import org.shedlang.compiler.ast.untyped.UntypedNamespaceStatementNode;
+import org.shedlang.compiler.ast.untyped.UntypedSumTypeDefinitionNode;
+import org.shedlang.compiler.typechecker.errors.CannotDefineSumTypeOutsideOfNamespace;
+import org.shedlang.compiler.types.NamespaceName;
+import org.shedlang.compiler.types.Types;
+import org.shedlang.compiler.util.P;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.equalTo;
+import static org.zwobble.precisely.Matchers.isOptionalOf;
+
+public class TypeCheckerSumTypeDefinitionTests {
+    private static final NamespaceName NAMESPACE_NAME = NamespaceName.of("Example");
+
+    @Test
+    public void whenOutsideOfNamespaceThenErrorIsThrown() {
+        var untyped = UntypedSumTypeDefinitionNode.builder()
+            .withName("ExampleSumType")
+            .build();
+        var context = TypeCheckerContext.EMPTY;
+
+        assertThrows(
+            CannotDefineSumTypeOutsideOfNamespace.class,
+            () -> TypeChecker.typeCheckNamespaceStatement(untyped).typeCheckAllPhases(context)
+        );
+    }
+
+    @Test
+    public void typeIsAddedToEnvironment() {
+        var untyped = UntypedSumTypeDefinitionNode.builder()
+            .withName("ExampleSumType")
+            .build();
+        var context = TypeCheckerContext.EMPTY;
+
+        var typed = typeCheckNamespaceStatement(untyped, context);
+
+        assertThat(
+            typed.context().compileTimeLookup("ExampleSumType"),
+            isOptionalOf(equalTo(Variable.defined(
+                Types.metaType(Types.sum(NAMESPACE_NAME, "ExampleSumType")),
+                VariableType.CONSTANT
+            )))
+        );
+    }
+
+    private static TypeCheckerResult<? extends TypedNamespaceStatementNode> typeCheckNamespaceStatement(
+        UntypedNamespaceStatementNode untyped,
+        TypeCheckerContext context
+    ) {
+        // TODO: remove duplication of this method
+        var declaredVariables = DeclaredVariables.forNamespaceStatement(untyped, P.vector());
+        var environment = EnvironmentBuilder.EMPTY.addUndefined(declaredVariables);
+
+        context = context.enterNamespace(NAMESPACE_NAME, environment.build());
+
+        return TypeChecker.typeCheckNamespaceStatement(untyped).typeCheckAllPhases(context);
+    }
+}