Parse return statements without expression

4 files changed, 22 insertions, 5 deletions

diff --git a/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java b/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
index 9e4ac8cd..5612ae3c 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/Untyped.java
@@ -6,6 +6,7 @@ import org.shedlang.compiler.types.Visibility;
 
 import java.math.BigInteger;
 import java.util.List;
+import java.util.Optional;
 
 public class Untyped {
     private Untyped() {
@@ -93,7 +94,7 @@ public class Untyped {
     }
 
     public static UntypedFunctionReturnNode functionReturn(UntypedExpressionNode expression) {
-        return new UntypedFunctionReturnNode(expression, Sources.NULL);
+        return new UntypedFunctionReturnNode(Optional.of(expression), Sources.NULL);
     }
 
     public static UntypedIfNode if_(
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 8fd2ce41..8eb92ebb 100644
--- a/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
+++ b/src/test/java/org/shedlang/compiler/ast/untyped/UntypedNodeMatchers.java
@@ -134,7 +134,7 @@ public class UntypedNodeMatchers {
     }
 
     public static Matcher<UntypedFunctionStatementNode> isUntypedFunctionReturnNode(
-        Matcher<UntypedExpressionNode> expression
+        Matcher<Optional<? extends UntypedExpressionNode>> expression
     ) {
         return instanceOf(
             UntypedFunctionReturnNode.class,
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserFunctionReturnTests.java b/src/test/java/org/shedlang/compiler/parser/ParserFunctionReturnTests.java
index 6e7f5cc3..7637bf58 100644
--- a/src/test/java/org/shedlang/compiler/parser/ParserFunctionReturnTests.java
+++ b/src/test/java/org/shedlang/compiler/parser/ParserFunctionReturnTests.java
@@ -5,14 +5,29 @@ 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.isOptionalEmpty;
+import static org.zwobble.precisely.Matchers.isOptionalOf;
 
 public class ParserFunctionReturnTests {
     @Test
-    public void canParseFunctionReturn() {
+    public void canParseFunctionReturnWithExpression() {
         var source = "return f;";
 
         var node = parseString(source, Parser::parseFunctionStatement);
 
-        assertThat(node, isUntypedFunctionReturnNode(isUntypedReferenceNode("f")));
+        assertThat(node, isUntypedFunctionReturnNode(
+            isOptionalOf(isUntypedReferenceNode("f"))
+        ));
+    }
+
+    @Test
+    public void canParseFunctionReturnWithoutExpression() {
+        var source = "return;";
+
+        var node = parseString(source, Parser::parseFunctionStatement);
+
+        assertThat(node, isUntypedFunctionReturnNode(
+            isOptionalEmpty()
+        ));
     }
 }
diff --git a/src/test/java/org/shedlang/compiler/parser/ParserWhenTests.java b/src/test/java/org/shedlang/compiler/parser/ParserWhenTests.java
index 709d7cce..b1ff9141 100644
--- a/src/test/java/org/shedlang/compiler/parser/ParserWhenTests.java
+++ b/src/test/java/org/shedlang/compiler/parser/ParserWhenTests.java
@@ -5,6 +5,7 @@ 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.isOptionalOf;
 import static org.zwobble.precisely.Matchers.isSequence;
 
 public class ParserWhenTests {
@@ -28,7 +29,7 @@ public class ParserWhenTests {
                 isUntypedWhenCaseNode(
                     isUntypedTypeLevelReferenceNode("A"),
                     isUntypedBlockNode(isSequence(
-                        isUntypedFunctionReturnNode(isUntypedIntLiteralNode(4))
+                        isUntypedFunctionReturnNode(isOptionalOf(isUntypedIntLiteralNode(4)))
                     ))
                 ),
                 isUntypedWhenCaseNode(