Support ignores at end of line (#26181).

pkg/analyzer/test/generated/error_suppression_test.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 
 import '../reflective_tests.dart';
 import '../utils.dart';
@@ skipping 24 matching lines @@
 // ignore: invalid_assignment
 int x = '';
 // ... but no ignore here ...
 const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source,
         [CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE]);
   }
 
+  void test_ignore_first_trailing() {
+    Source source = addSource('''
+int x = ''; // ignore: invalid_assignment
+// ... but no ignore here ...
+const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
+''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source,
+        [CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE]);
+  }
+
+  void test_ignore_only_trailing() {
+    Source source = addSource('''
+int x = ''; // ignore: invalid_assignment
+''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, []);
+  }
+
   void test_ignore_second() {
     Source source = addSource('''
 //INVALID_ASSIGNMENT
 int x = '';
 // ignore: const_initialized_with_non_constant_value
 const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source, [StaticTypeWarningCode.INVALID_ASSIGNMENT]);
   }
 
+  void test_ignore_second_trailing() {
+    Source source = addSource('''
+//INVALID_ASSIGNMENT
+int x = '';
+const y = x; // ignore: const_initialized_with_non_constant_value
+''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, [StaticTypeWarningCode.INVALID_ASSIGNMENT]);
+  }
+
   void test_invalid_error_code() {
     Source source = addSource('''
 // ignore: right_format_wrong_code
 int x = '';
 const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source, [
       StaticTypeWarningCode.INVALID_ASSIGNMENT,
       CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
@@ skipping 35 matching lines @@
   void test_multiple_ignores() {
     Source source = addSource('''
 int x = 3;
 // ignore: invalid_assignment, const_initialized_with_non_constant_value
 const String y = x; //INVALID_ASSIGNMENT, CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source, []);
   }
 
+  void test_multiple_ignores_traling() {
+    Source source = addSource('''
+int x = 3;
+const String y = x; // ignore: invalid_assignment, const_initialized_with_non_constant_value
+''');
+    computeLibrarySourceErrors(source);
+    assertErrors(source, []);
+  }
+
   void test_multiple_ignores_whitespace_variant_1() {
     Source source = addSource('''
 int x = 3;
 //ignore:invalid_assignment,const_initialized_with_non_constant_value
 const String y = x; //INVALID_ASSIGNMENT, CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source, []);
   }
 
@@ skipping 22 matching lines @@
 int x = '';  //INVALID_ASSIGNMENT
 const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
 ''');
     computeLibrarySourceErrors(source);
     assertErrors(source, [
       StaticTypeWarningCode.INVALID_ASSIGNMENT,
       CompileTimeErrorCode.CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
     ]);
   }
 }