A whitespace-only change can be incremental anywhere.

pkg/analyzer/test/generated/incremental_resolver_test.dart

 // Copyright (c) 2014, 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 engine.incremental_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
@@ skipping 2160 matching lines @@
   String code;
   LibraryElement oldLibrary;
   CompilationUnit oldUnit;
   CompilationUnitElement oldUnitElement;
 
   void setUp() {
     super.setUp();
     _resetWithIncremental(true);
   }
 
+  void test_false_topLevelFunction_name() {
+    _resolveUnit(r'''
+a() {}
+b() {}
+''');
+    _updateAndValidate(r'''
+a() {}
+bb() {}
+''', expectedSuccess: false);
+  }
+
   void test_inBody_expression() {
     _resolveUnit(r'''
 class A {
   m() {
     print(1);
   }
 }
 ''');
     _updateAndValidate(r'''
 class A {
@@ skipping 41 matching lines @@
   }
 }''');
     for (int i = 0; i < 6; i++) {
       if (i.isEven) {
         _updateAndValidate(r'''
 class A {
   m() {
     return true;
 
   }
-}''', false);
+}''', compareWithFull: false);
       } else {
         _updateAndValidate(r'''
 class A {
   m() {
     return true;
   }
-}''', false);
+}''', compareWithFull: false);
       }
     }
   }
 
   void test_multiple_expression() {
     _resolveUnit(r'''
 main() {
   print(1);
 }''');
     for (int i = 0; i < 6; i++) {
       if (i.isEven) {
         _updateAndValidate(r'''
 main() {
   print(12);
-}''', false);
+}''', compareWithFull: false);
       } else {
         _updateAndValidate(r'''
 main() {
   print(1);
-}''', false);
+}''', compareWithFull: false);
       }
     }
   }
 
+  void test_true_emptyLine_betweenClassMembers_insert() {
+    _resolveUnit(r'''
+class A {
+  a() {}
+  b() {}
+}
+''');
+    _updateAndValidate(r'''
+class A {
+  a() {}
+
+  b() {}
+}
+''');
+  }
+
+  void test_true_emptyLine_betweenClassMembers_remove() {
+    _resolveUnit(r'''
+class A {
+  a() {}
+
+  b() {}
+}
+''');
+    _updateAndValidate(r'''
+class A {
+  a() {}
+  b() {}
+}
+''');
+  }
+
+  void test_true_emptyLine_betweenCompilationUnitMembers_insert() {
+    _resolveUnit(r'''
+a() {}
+b() {}
+''');
+    _updateAndValidate(r'''
+a() {}
+
+b() {}
+''');
+  }
+
+  void test_true_emptyLine_betweenCompilationUnitMembers_remove() {
+    _resolveUnit(r'''
+a() {
+  print(1)
+}
+
+b() {
+  foo(42);
+}
+foo(String p) {};
+''');
+    _updateAndValidate(r'''
+a() {
+  print(1)
+}
+b() {
+  foo(42);
+}
+foo(String p) {};
+''');
+  }
+
   void test_true_wholeConstructor() {
     _resolveUnit(r'''
 class A {
   A(int a) {
     print(a);
   }
 }
 ''');
     _updateAndValidate(r'''
 class A {
@@ skipping 202 matching lines @@
     oldUnitElement = oldUnit.element;
   }
 
   void _runTasks() {
     AnalysisResult result = analysisContext.performAnalysisTask();
     while (result.changeNotices != null) {
       result = analysisContext.performAnalysisTask();
     }
   }
 
-  void _updateAndValidate(String newCode, [bool compareWithFull = true]) {
+  void _updateAndValidate(String newCode, {bool expectedSuccess: true,
+      bool compareWithFull: true}) {
     // Run any pending tasks tasks.
     _runTasks();
     // Update the source - currently this may cause incremental resolution.
     // Then request the updated resolved unit.
     _resetWithIncremental(true);
     analysisContext2.setContents(source, newCode);
     CompilationUnit newUnit = resolveCompilationUnit(source, oldLibrary);
     List<AnalysisError> newErrors = analysisContext.getErrors(source).errors;
+    // check for expected failure
+    if (!expectedSuccess) {
+      expect(newUnit.element, isNot(same(oldUnitElement)));
+      return;
+    }
     // The existing CompilationUnitElement should be updated.
     expect(newUnit.element, same(oldUnitElement));
     // The only expected pending task should return the same resolved
     // "newUnit", so all clients will get it using the usual way.
     AnalysisResult analysisResult = analysisContext.performAnalysisTask();
     ChangeNotice notice = analysisResult.changeNotices[0];
     expect(notice.compilationUnit, same(newUnit));
     // Resolve "newCode" from scratch.
     if (compareWithFull) {
       _resetWithIncremental(false);
@@ skipping 1118 matching lines @@
     _visitList(node.metadata, other.metadata);
     _visitNode(node.identifier, other.identifier);
   }
 
   static void assertSameResolution(CompilationUnit actual,
       CompilationUnit expected) {
     _SameResolutionValidator validator = new _SameResolutionValidator(expected);
     actual.accept(validator);
   }
 }