2 files changed, 53 insertions, 2 deletions
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java b/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
index 31ead2a..1bafe96 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/parser/Parser.java
@@ -166,11 +166,17 @@ public class Parser {
         tokens.skip(TokenType.SYMBOL_BRACE_OPEN);
 
         var variants = parseMany(
-            () -> tokens.isNext(TokenType.SYMBOL_BRACE_CLOSE),
+            () -> !tokens.isNext(TokenType.KEYWORD_VARIANT),
             () -> parseSumVariantDefinition(tokens),
             () -> true
         );
 
+        var fields = parseMany(
+            () -> !tokens.isNext(TokenType.KEYWORD_FIELD),
+            () -> parseStructFieldDefinition(tokens),
+            () -> true
+        );
+
         tokens.skip(TokenType.SYMBOL_BRACE_CLOSE);
 
         var end = tokens.endPosition();
@@ -179,7 +185,7 @@ public class Parser {
         return new UntypedSumDefinitionNode(
             name.charSequence().toString(),
             variants,
-            List.of(),
+            fields,
             docComment,
             source
         );
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserSumDefinitionTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserSumDefinitionTests.java
index 34b94fc..20de7ba 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserSumDefinitionTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/parser/ParserSumDefinitionTests.java
@@ -6,6 +6,9 @@ import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedSumDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedSumVariantDefinitionNode;
 import org.zwobble.hobgoblin.compiler.ast.untyped.UntypedTypeLevelReferenceNode;
 
+import static org.zwobble.hobgoblin.compiler.ast.untyped.UntypedStructFieldDefinitionNodeMatcher.isUntypedStructFieldDefinitionNode;
+import static org.zwobble.hobgoblin.compiler.ast.untyped.UntypedSumDefinitionNodeMatcher.isUntypedSumDefinitionNode;
+import static org.zwobble.hobgoblin.compiler.ast.untyped.UntypedTypeLevelReferenceNodeMatcher.isUntypedTypeLevelReferenceNode;
 import static org.zwobble.hobgoblin.compiler.parser.ParserTesting.parseString;
 import static org.zwobble.precisely.AssertThat.assertThat;
 import static org.zwobble.precisely.Matchers.*;
@@ -82,6 +85,48 @@ public class ParserSumDefinitionTests {
     }
 
     @Test
+    public void emptySumHasNoFields() {
+        var source = """
+            sum Shape {
+            }""";
+
+        var node = parseString(
+            source,
+            Parser::parseNamespaceStatement
+        );
+
+        assertThat(node, instanceOf(
+            UntypedSumDefinitionNode.class,
+            has("fields", UntypedSumDefinitionNode::fields, isSequence())
+        ));
+    }
+
+    @Test
+    public void sumWithFields() {
+        var source = """
+            sum Shape {
+                field height: Int32;
+                field width: Int64;
+            }""";
+
+        var node = parseString(
+            source,
+            Parser::parseNamespaceStatement
+        );
+
+        assertThat(node, isUntypedSumDefinitionNode()
+            .withFields(isSequence(
+                isUntypedStructFieldDefinitionNode()
+                    .withName(equalTo("height"))
+                    .withType(isUntypedTypeLevelReferenceNode().withName(equalTo("Int32"))),
+                isUntypedStructFieldDefinitionNode()
+                    .withName(equalTo("width"))
+                    .withType(isUntypedTypeLevelReferenceNode().withName(equalTo("Int64")))
+            ))
+        );
+    }
+
+    @Test
     public void sumWithDocComment() {
         var source = """
             /// A 2D shape.