Issue 21883. Add checks if type parameters can be used.

pkg/analysis_server/test/services/correction/assist_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 test.services.correction.assist;
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:analysis_server/src/services/correction/assist.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/index/local_memory_index.dart';
@@ skipping 148 matching lines @@
     verifyNoTestUnitErrors = false;
     _indexTestUnit('''
 main() {
   for (var item in unknownList) {
   }
 }
 ''');
     assertNoAssistAt('item in', AssistKind.ADD_TYPE_ANNOTATION);
   }
 
+  void test_addTypeAnnotation_declaredIdentifier_generic_OK() {
+    _indexTestUnit('''
+class A<T> {
+  main(List<List<T>> items) {
+    for (var item in items) {
+    }
+  }
+}
+''');
+    assertHasAssistAt('item in', AssistKind.ADD_TYPE_ANNOTATION, '''
+class A<T> {
+  main(List<List<T>> items) {
+    for (List<T> item in items) {
+    }
+  }
+}
+''');
+  }
+
   void test_addTypeAnnotation_declaredIdentifier_OK() {
     _indexTestUnit('''
 main(List<String> items) {
   for (var item in items) {
   }
 }
 ''');
     // on identifier
     assertHasAssistAt('item in', AssistKind.ADD_TYPE_ANNOTATION, '''
 main(List<String> items) {
@@ skipping 40 matching lines @@
 }
 ''');
     assertHasAssistAt('item in', AssistKind.ADD_TYPE_ANNOTATION, '''
 main(List<String> items) {
   for (final String item in items) {
   }
 }
 ''');
   }
 
+  void test_addTypeAnnotation_local_generic_OK_literal() {
+    _indexTestUnit('''
+class A {
+  main(List<int> items) {
+    var v = items;
+  }
+}
+''');
+    assertHasAssistAt('v =', AssistKind.ADD_TYPE_ANNOTATION, '''
+class A {
+  main(List<int> items) {
+    List<int> v = items;
+  }
+}
+''');
+  }
+
+  void test_addTypeAnnotation_local_generic_OK_local() {
+    _indexTestUnit('''
+class A<T> {
+  main(List<T> items) {
+    var v = items;
+  }
+}
+''');
+    assertHasAssistAt('v =', AssistKind.ADD_TYPE_ANNOTATION, '''
+class A<T> {
+  main(List<T> items) {
+    List<T> v = items;
+  }
+}
+''');
+  }
+
   void test_addTypeAnnotation_local_OK_addImport_dartUri() {
     addSource('/my_lib.dart', r'''
 import 'dart:async';
 Future<int> getFutureInt() => null;
 ''');
     _indexTestUnit('''
 import 'my_lib.dart';
 main() {
   var v = getFutureInt();
 }
@@ skipping 2008 matching lines @@
 ''');
     // not binary expression
     assertNoAssistAt('main() {', AssistKind.SPLIT_AND_CONDITION);
     // selection is not empty and includes more than just operator
     {
       length = 5;
       assertNoAssistAt('&& 2 == 2', AssistKind.SPLIT_AND_CONDITION);
     }
   }
 
-  void test_splitAndCondition_wrong_notAnd() {
-    _indexTestUnit('''
-main() {
-  if (1 == 1 || 2 == 2) {
-    print(0);
-  }
-}
-''');
-    assertNoAssistAt('|| 2', AssistKind.SPLIT_AND_CONDITION);
-  }
-
   void test_splitAndCondition_wrong_hasElse() {
     _indexTestUnit('''
 main() {
   if (1 == 1 && 2 == 2) {
     print(1);
   } else {
     print(2);
   }
 }
 ''');
     assertNoAssistAt('&& 2', AssistKind.SPLIT_AND_CONDITION);
   }
 
+  void test_splitAndCondition_wrong_notAnd() {
+    _indexTestUnit('''
+main() {
+  if (1 == 1 || 2 == 2) {
+    print(0);
+  }
+}
+''');
+    assertNoAssistAt('|| 2', AssistKind.SPLIT_AND_CONDITION);
+  }
+
   void test_splitAndCondition_wrong_notPartOfIf() {
     _indexTestUnit('''
 main() {
   print(1 == 1 && 2 == 2);
 }
 ''');
     assertNoAssistAt('&& 2', AssistKind.SPLIT_AND_CONDITION);
   }
 
   void test_splitAndCondition_wrong_notTopLevelAnd() {
@@ skipping 277 matching lines @@
   void _indexTestUnit(String code) {
     resolveTestUnit(code);
     index.indexUnit(context, testUnit);
   }
 
   void _setStartEndSelection() {
     offset = findOffset('// start\n') + '// start\n'.length;
     length = findOffset('// end') - offset;
   }
 }