Parse sum types

2 files changed, 50 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
index d08e784d..ddb7db96 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
@@ -209,6 +209,17 @@ public class UntypedNodeMatchers {
         return isUntypedBinaryOperationNode(UntypedBinaryOperator.SUB, left, right);
     }
 
+    public static Matcher<UntypedNamespaceStatementNode> isUntypedSumTypeDefinitionNode(
+        String name,
+        Matcher<Iterable<? extends UntypedTypeLevelExpressionNode>> variants
+    ) {
+        return instanceOf(
+            UntypedSumTypeDefinitionNode.class,
+            has("name", x -> x.name(), equalTo(name)),
+            has("variants", x -> x.variants(), variants)
+        );
+    }
+
     public static Matcher<UntypedTargetNode> isUntypedTargetIgnoreNode() {
         return instanceOf(UntypedTargetNode.Ignore.class);
     }
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserSumTypeDefinitionTests.java b/src/test/java/org/shedlang/compiler/parser/ParserSumTypeDefinitionTests.java
new file mode 100644
index 00000000..65a8ef6f
--- /dev/null
+++ b/src/test/java/org/shedlang/compiler/parser/ParserSumTypeDefinitionTests.java
@@ -0,0 +1,39 @@
+package org.shedlang.compiler.parser;
+
+import org.junit.jupiter.api.Test;
+
+import static org.shedlang.compiler.ast.untyped.UntypedNodeMatchers.*;
+import static org.shedlang.compiler.parser.ParserTesting.parseString;
+import static org.zwobble.precisely.AssertThat.assertThat;
+import static org.zwobble.precisely.Matchers.isSequence;
+
+public class ParserSumTypeDefinitionTests {
+    @Test
+    public void canParseSumTypeWithSingleVariant() {
+        var source = "sumtype Option = Some;";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedSumTypeDefinitionNode("Option", isSequence(
+                isUntypedTypeLevelReferenceNode("Some")
+            ))
+        );
+    }
+
+    @Test
+    public void canParseSumTypeWithMultipleVariant() {
+        var source = "sumtype Option = Some | None;";
+
+        var node = parseString(source, Parser::parseNamespaceStatement);
+
+        assertThat(
+            node,
+            isUntypedSumTypeDefinitionNode("Option", isSequence(
+                isUntypedTypeLevelReferenceNode("Some"),
+                isUntypedTypeLevelReferenceNode("None")
+            ))
+        );
+    }
+}