Issue 40701. Include 'late' into unlinked API signature.

R=brianwilkerson@google.com, pquitslund@google.com

Bug: #40701
Change-Id: Ia11ff4e65e779c4a370a6fec539564c0533bffa3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/136529
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>

pkg/analyzer/lib/src/dart/analysis/driver.dart

@@ -91,7 +91,7 @@ typedef WorkToWaitAfterComputingResult = Future<void> Function(String path);
 /// TODO(scheglov) Clean up the list of implicitly analyzed files.
 class AnalysisDriver implements AnalysisDriverGeneric {
   /// The version of data format, should be incremented on every format change.
-  static const int DATA_VERSION = 96;
+  static const int DATA_VERSION = 97;
 
   /// The length of the list returned by [_computeDeclaredVariablesSignature].
   static const int _declaredVariablesSignatureLength = 4;

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -10482,7 +10482,9 @@ class VariableDeclarationListImpl extends AnnotatedNodeImpl
 
   @override
   Token get firstTokenAfterCommentAndMetadata {
-    if (keyword != null) {
+    if (lateKeyword != null) {
+      return lateKeyword;
+    } else if (keyword != null) {
       return keyword;
     } else if (_type != null) {
       return _type.beginToken;

pkg/analyzer/test/src/dart/analysis/unlinked_api_signature_test.dart

@@ -2,7 +2,9 @@
 // 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.
 
+import 'package:analyzer/dart/analysis/features.dart';
 import 'package:analyzer/src/dart/analysis/unlinked_api_signature.dart';
+import 'package:analyzer/src/generated/engine.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -11,6 +13,7 @@ import '../ast/parse_base.dart';
 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(UnitApiSignatureTest);
+    defineReflectiveTests(UnitApiSignatureWithNullSafetyTest);
   });
 }
 
@@ -199,6 +202,30 @@ class B extends A {}
 ''');
   }
 
+  test_class_field_final_add() {
+    assertNotSameSignature(r'''
+class C {
+  int a = 0;
+}
+''', r'''
+class C {
+  final int a = 0;
+}
+''');
+  }
+
+  test_class_field_static_add() {
+    assertNotSameSignature(r'''
+class C {
+  int a;
+}
+''', r'''
+class C {
+  static int a;
+}
+''');
+  }
+
   test_class_field_withoutType() {
     assertNotSameSignature(r'''
 class C {
@@ -790,7 +817,7 @@ class A {}
 // @dart = 2.6
 class A {}
 ''', r'''
-// @dart = 2.5
+// @dart = 2.2
 class A {}
 ''');
   }
@@ -1011,6 +1038,14 @@ mixin M on A {}
 ''');
   }
 
+  test_topLevelVariable_final_add() {
+    assertNotSameSignature(r'''
+int a = 0;
+''', r'''
+final int a = 0;
+''');
+  }
+
   test_topLevelVariable_withoutType() {
     assertNotSameSignature(r'''
 var a = 1;
@@ -1075,3 +1110,51 @@ typedef F = void Function(double);
 ''');
   }
 }
+
+@reflectiveTest
+class UnitApiSignatureWithNullSafetyTest extends UnitApiSignatureTest {
+  @override
+  AnalysisOptionsImpl get analysisOptions => AnalysisOptionsImpl()
+    ..contextFeatures = FeatureSet.forTesting(
+        sdkVersion: '2.3.0', additionalFeatures: [Feature.non_nullable]);
+
+  test_class_field_late_add() {
+    assertNotSameSignature(r'''
+class C {
+  int a;
+}
+''', r'''
+class C {
+  late int a;
+}
+''');
+  }
+
+  test_class_field_late_remove() {
+    assertNotSameSignature(r'''
+class C {
+  late int a;
+}
+''', r'''
+class C {
+  int a;
+}
+''');
+  }
+
+  test_topLevelVariable_late_add() {
+    assertNotSameSignature(r'''
+int a;
+''', r'''
+late int a;
+''');
+  }
+
+  test_topLevelVariable_late_remove() {
+    assertNotSameSignature(r'''
+late int a;
+''', r'''
+int a;
+''');
+  }
+}