Ensure field is set to correct value

2 files changed, 27 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 7ff8bb1..f0ecbd1 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/values/ObjectInterpreterValue.java
@@ -5,8 +5,11 @@ import java.util.Map;
 import java.util.Optional;
 
 import org.zwobble.couscous.interpreter.NoSuchField;
+import org.zwobble.couscous.interpreter.UnexpectedValueType;
 import org.zwobble.couscous.values.PrimitiveValue;
 
+import lombok.val;
+
 public class ObjectInterpreterValue implements InterpreterValue {
     private final ConcreteType type;
     private final Map<String, InterpreterValue> fields;
@@ -36,7 +39,10 @@ public class ObjectInterpreterValue implements InterpreterValue {
     }
 
     public void setField(String fieldName, InterpreterValue value) {
-        type.getField(fieldName).orElseThrow(() -> new NoSuchField(fieldName));
+        val field = type.getField(fieldName).orElseThrow(() -> new NoSuchField(fieldName));
+        if (!field.getType().equals(value.getType().getName())) {
+            throw new UnexpectedValueType(field.getType(), value.getType().getName());
+        }
         fields.put(fieldName, value);   
     }
 }
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 7c5594a..808c2a7 100644
--- a/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
+++ b/src/test/java/org/zwobble/couscous/tests/interpreter/EvaluatorTests.java
@@ -134,6 +134,26 @@ public class EvaluatorTests extends BackendEvalTests {
         assertEquals(new NoSuchField("value"), exception);
     }
     
+    @Test
+    public void cannotSetValueOfFieldWithWrongType() {
+        val classNode = ClassNode.builder("com.example.Example")
+            .field("value", IntegerValue.REF)
+            .constructor(constructor -> constructor
+                .statement(assignStatement(
+                    fieldAccess(constructor.thisReference(), "value", IntegerValue.REF),
+                    literal(""))))
+            .build();
+        
+        val exception = assertThrows(UnexpectedValueType.class,
+            () -> evalExpression(
+                asList(classNode),
+                constructorCall(
+                    classNode.getName(),
+                    asList())));
+        
+        assertEquals(new UnexpectedValueType(IntegerValue.REF, StringValue.REF), exception);
+    }
+    
     private static Environment emptyEnvironment() {
         return new Environment(
             JavaProject.builder().build(),