Require explicit exit behaviour of handler methods

1 files changed, 32 insertions, 0 deletions

diff --git a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
index 88254905..f1a68abf 100644
--- a/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
+++ b/src/test/java/org/shedlang/compiler/typechecker/TypeCheckerTryTests.java
@@ -594,4 +594,36 @@ public class TypeCheckerTryTests {
         assertThat(error.allowed(), equalTo(Effects.NONE));
         assertThat(error.actual(), equalTo(handledEffect));
     }
+
+    @Test
+    public void whenHandlerMethodReachesEndOfBodyThenErrorIsThrown() {
+        var handledEffect = Effects.userDefined(NAMESPACE_NAME, "HandledEffect");
+        var untyped = UntypedTryNode.builder()
+            .withHandledEffect(Untyped.typeLevelReference(handledEffect.name()))
+            .addHandlerMethod(
+                UntypedTryHandlerMethodNode.builder()
+                    .withName("mark")
+                    .build()
+            )
+            .build();
+        var context = TypeCheckerContext.EMPTY
+            .addUserDefinedEffectInfo(
+                handledEffect,
+                UserDefinedEffectInfo.builder()
+                    .addMethod("mark", FunctionType.builder().withReturnType(Types.UNIT).build())
+                    .build()
+            )
+            .enterFunction(
+                P.map(
+                    Map.entry(handledEffect.name(), Variable.defined(Types.effectType(handledEffect), VariableType.CONSTANT))
+                ),
+                Effects.NONE,
+                Optional.empty()
+            );
+
+        assertThrows(
+            EffectHandlerMethodMustResumeOrExitError.class,
+            () -> typeCheckExpression(untyped, context)
+        );
+    }
 }