Check row type is struct

3 files changed, 53 insertions, 4 deletions

diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/TypeChecker.java b/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/TypeChecker.java
index eb3e09d..211726b 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/TypeChecker.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/TypeChecker.java
@@ -468,12 +468,18 @@ public class TypeChecker {
         UntypedTableDefinitionNode untyped,
         TypeCheckerNamespaceContext context
     ) {
-        var rowType = typeCheckMetaType(untyped.rowType(), context);
+        var rowTypeTypedNode = typeCheckMetaType(untyped.rowType(), context);
+
+        if (!(rowTypeTypedNode.value() instanceof StructType rowType)) {
+            throw new TableRowTypeMustBeStructError(
+                rowTypeTypedNode.value(),
+                rowTypeTypedNode.source()
+            );
+        }
 
         return new TypedTableDefinitionNode(
             untyped.name(),
-            // TODO: handle not struct type.
-            (StructType) rowType.value(),
+            rowType,
             // TODO: check primary key is valid.
             untyped.primaryKey(),
             untyped.docComment(),
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/errors/TableRowTypeMustBeStructError.java b/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/errors/TableRowTypeMustBeStructError.java
new file mode 100644
index 0000000..17b93d4
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/typechecker/errors/TableRowTypeMustBeStructError.java
@@ -0,0 +1,18 @@
+package org.zwobble.hobgoblin.compiler.typechecker.errors;
+
+import org.zwobble.hobgoblin.compiler.errors.SourceError;
+import org.zwobble.hobgoblin.compiler.sources.Source;
+import org.zwobble.hobgoblin.compiler.types.Type;
+
+public class TableRowTypeMustBeStructError extends SourceError {
+    private final Type rowType;
+
+    public TableRowTypeMustBeStructError(Type rowType, Source source) {
+        super("row types must be structs, but was " + rowType.describe(), source);
+        this.rowType = rowType;
+    }
+
+    public Type rowType() {
+        return rowType;
+    }
+}
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerTableDefinitionTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerTableDefinitionTests.java
index 7c08688..a4e1cf4 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerTableDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/typechecker/TypeCheckerTableDefinitionTests.java
@@ -4,10 +4,13 @@ import org.junit.jupiter.api.Test;
 import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedTableDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedTypeLevelReferenceNode;
 import org.zwobble.hobgoblin.compiler.sources.NullSource;
+import org.zwobble.hobgoblin.compiler.typechecker.errors.TableRowTypeMustBeStructError;
 import org.zwobble.hobgoblin.compiler.types.NamespaceName;
+import org.zwobble.hobgoblin.compiler.types.SimpleNativeType;
 import org.zwobble.hobgoblin.compiler.types.SimpleStructType;
 import org.zwobble.hobgoblin.compiler.types.Types;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.zwobble.hobgoblin.compiler.ast.typed.TypedTableDefinitionNodeMatcher.isTypedTableDefinitionNode;
 import static org.zwobble.hobgoblin.compiler.typechecker.TypeChecker.typeCheckDatabaseSchemaStatement;
 import static org.zwobble.precisely.AssertThat.assertThat;
@@ -15,7 +18,7 @@ import static org.zwobble.precisely.Matchers.equalTo;
 
 public class TypeCheckerTableDefinitionTests {
     @Test
-    public void databaseSchemaStatementsAreTypeChecked() {
+    public void minimalTableDefinition() {
         var untyped = UntypedTableDefinitionNode.arbitrary()
             .withName("authors")
             .withRowType(UntypedTypeLevelReferenceNode.arbitrary()
@@ -35,4 +38,26 @@ public class TypeCheckerTableDefinitionTests {
             .withRowType(equalTo(authorType))
         );
     }
+
+    @Test
+    public void whenRowTypeIsNotStructTypeThenErrorIsThrown() {
+        var untyped = UntypedTableDefinitionNode.arbitrary()
+            .withName("authors")
+            .withRowType(UntypedTypeLevelReferenceNode.arbitrary()
+                .withName("Author")
+                .build()
+            )
+            .build();
+        var globalContext = TypeCheckerContextArb.globalContext();
+        var namespaceContext = globalContext.enterNamespace(NamespaceName.of("App"));
+        var authorType = new SimpleNativeType(NamespaceName.of("App"), "Author");
+        namespaceContext.declare("Author", Types.metaType(authorType), NullSource.INSTANCE);
+
+        var error = assertThrows(
+            TableRowTypeMustBeStructError.class,
+            () -> typeCheckDatabaseSchemaStatement(untyped, namespaceContext)
+        );
+
+        assertThat(error.rowType(), equalTo(authorType));
+    }
 }