Throw error when trying to get undeclared field

2 files changed, 19 insertions, 1 deletions

diff --git a/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java b/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
index 6e653d2..b6a1e87 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
@@ -34,7 +34,7 @@ public class ObjectInterpreterValue implements InterpreterValue {
         if (fields.containsKey(fieldName)) {
             return fields.get(fieldName);            
         } else {
-            throw new UnsupportedOperationException();
+            throw new NoSuchField(fieldName);
         }
     }
 
diff --git a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
index 808c2a7..0f96fe7 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
@@ -116,6 +116,24 @@ public class EvaluatorTests extends BackendEvalTests {
     }
     
     @Test
+    public void cannotGetValueOfUndeclaredField() {
+        val classNode = ClassNode.builder("com.example.Example")
+            .build();
+        
+        val exception = assertThrows(NoSuchField.class,
+            () -> evalExpression(
+                asList(classNode),
+                fieldAccess(
+                    constructorCall(
+                        classNode.getName(),
+                        asList()),
+                    "value",
+                    IntegerValue.REF)));
+        
+        assertEquals(new NoSuchField("value"), exception);
+    }
+    
+    @Test
     public void cannotSetValueOfUndeclaredField() {
         val classNode = ClassNode.builder("com.example.Example")
             .constructor(constructor -> constructor