Support ignores at end of line (#26181).

pkg/analyzer/test/generated/error_suppression_test.dart

Index: pkg/analyzer/test/generated/error_suppression_test.dart
diff --git a/pkg/analyzer/test/generated/error_suppression_test.dart b/pkg/analyzer/test/generated/error_suppression_test.dart
index c77bb3d3c48a5c967df3f67c652c7ba12b7f58c8..275e94ccc54468a5fdb35f8bda42547aaf2687eb 100644
--- a/pkg/analyzer/test/generated/error_suppression_test.dart
+++ b/pkg/analyzer/test/generated/error_suppression_test.dart
@@ -42,6 +42,25 @@ const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
         [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
@@ -53,6 +72,16 @@ const y = x; //CONST_INITIALIZED_WITH_NON_CONSTANT_VALUE
     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
@@ -108,6 +137,15 @@ const String y = x; //INVALID_ASSIGNMENT, CONST_INITIALIZED_WITH_NON_CONSTANT_VA
     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;