analyzer strong mode: infer final field from initializer if super getters are dynamic

pkg/analyzer/test/src/task/strong_mode_test.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library test.src.task.strong_mode_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/strong_mode.dart';
@@ skipping 223 matching lines @@
     PropertyAccessorElement getterB = classB.getGetter(fieldName);
     expect(fieldB.type.isDynamic, isTrue);
     expect(getterB.returnType.isDynamic, isTrue);
 
     inferrer.inferCompilationUnit(unit);
 
     expect(fieldB.type, fieldA.type);
     expect(getterB.returnType, getterA.returnType);
   }
 
+  void test_inferCompilationUnit_field_single_final_narrowType() {
+    InstanceMemberInferrer inferrer = createInferrer;
+    String fieldName = 'f';
+    CompilationUnitElement unit = resolve('''
+class A {
+  final $fieldName;
+}
+class B extends A {
+  final $fieldName = 0;
+}
+''');
+    ClassElement classA = unit.getType('A');
+    FieldElement fieldA = classA.getField(fieldName);
+    PropertyAccessorElement getterA = classA.getGetter(fieldName);
+    ClassElement classB = unit.getType('B');
+    FieldElement fieldB = classB.getField(fieldName);
+    PropertyAccessorElement getterB = classB.getGetter(fieldName);
+    expect(fieldB.type.isDynamic, isTrue);
+    expect(getterB.returnType.isDynamic, isTrue);
+
+    inferrer.inferCompilationUnit(unit);
+
+    expect(fieldB.type, inferrer.typeProvider.intType);
+    expect(getterB.returnType, fieldB.type);
+  }
+
   void test_inferCompilationUnit_field_single_generic() {
     InstanceMemberInferrer inferrer = createInferrer;
     String fieldName = 'f';
     CompilationUnitElement unit = resolve('''
 class A<E> {
   E $fieldName;
 }
 class B<E> extends A<E> {
   var $fieldName;
 }
@@ skipping 741 matching lines @@
     }
   }
 }
 ''');
     CompilationUnit unit = context.resolveCompilationUnit2(source, source);
     VariableGatherer gatherer = new VariableGatherer(filter);
     unit.accept(gatherer);
     return gatherer.results;
   }
 }