GROOVY-11329: Class using trait and @immutable and allProperties gives BUG! exception in phase 'canonicalization' NPE

Author: paulk-asert

src/main/java/groovy/transform/options/ImmutablePropertyHandler.java

@@ -234,7 +234,10 @@ private static Statement assignFieldWithDefault(final Parameter map, final Field
         get.setImplicitThis(false);
         MethodCallExpression containsKey = callX(varX(map), "containsKey", nameArg);
         containsKey.setImplicitThis(false);
-        fNode.getDeclaringClass().getField(fNode.getName()).setInitialValueExpression(null); // to avoid default initialization
+        // avoid NPE if no declaring class - can be the case for traits
+        if (fNode.getDeclaringClass() != null) {
+            fNode.getDeclaringClass().getField(fNode.getName()).setInitialValueExpression(null); // to avoid default initialization
+        }
         return ifElseS(containsKey, assignStmt, assignInit);
     }
 

src/test/org/codehaus/groovy/transform/ImmutableTransformTest.groovy

@@ -1063,4 +1063,23 @@ final class ImmutableTransformTest {
             assert obj['data'][2L] == 'bar'
         '''
     }
+
+    // GROOVY-11329
+    @Test
+    void testAllPropertiesAndTrait() {
+        assertScript shell, '''
+            import groovy.transform.Immutable
+
+            trait T {
+                String foo
+            }
+
+            @Immutable(allProperties=true)
+            class C implements T {
+                String bar
+            }
+
+            assert new C('bar', 'foo').toString() == 'C(bar, foo)'
+        '''
+    }
 }