Issue 25021. Fix for adding new required parameters when optional exist.

pkg/analysis_server/test/services/correction/fix_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.fix;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/edit/fix/fix_dart.dart';
@@ skipping 157 matching lines @@
         '''
 class Test {
   final int a;
   final int b;
   final int c;
   Test(this.a, this.b, [this.c]);
 }
 ''');
   }
 
+  test_addMissingParameter_function_positional_hasNamed() async {
+    resolveTestUnit('''
+test({int a}) {}
+main() {
+  test(1);
+}
+''');
+    await assertNoFix(DartFixKind.ADD_MISSING_PARAMETER_POSITIONAL);
+  }
+
   test_addMissingParameter_function_positional_hasZero() async {
     resolveTestUnit('''
 test() {}
 main() {
   test(1);
 }
 ''');
     await assertHasFix(
         DartFixKind.ADD_MISSING_PARAMETER_POSITIONAL,
         '''
 test([int i]) {}
 main() {
   test(1);
 }
 ''');
   }
 
+  test_addMissingParameter_function_required_hasNamed() async {
+    resolveTestUnit('''
+test({int a}) {}
+main() {
+  test(1);
+}
+''');
+    await assertHasFix(
+        DartFixKind.ADD_MISSING_PARAMETER_REQUIRED,
+        '''
+test(int i, {int a}) {}
+main() {
+  test(1);
+}
+''');
+  }
+
   test_addMissingParameter_function_required_hasOne() async {
     resolveTestUnit('''
 test(int a) {}
 main() {
   test(1, 2.0);
 }
 ''');
     await assertHasFix(
         DartFixKind.ADD_MISSING_PARAMETER_REQUIRED,
         '''
@@ skipping 4414 matching lines @@
       int offset = resultCode.indexOf(search);
       positions.add(new Position(testFile, offset));
     }
     return positions;
   }
 
   void _performAnalysis() {
     while (context.performAnalysisTask().hasMoreWork);
   }
 }