Fix hover documentation for parameters.

pkg/analysis_server/test/analysis/get_hover_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.domain.analysis.hover;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ skipping 150 matching lines @@
       expect(hover.elementDescription, 'mmm(int a, String b) → List<String>');
       expect(hover.elementKind, 'method');
       // types
       expect(hover.staticType, isNull);
       expect(hover.propagatedType, isNull);
       // no parameter
       expect(hover.parameter, isNull);
     });
   }
 
+  test_expression_parameter() {
+    addTestFile('''
+library my.library;
+class A {
+  /// The method documentation.
+  m(int p) {
+  }
+}
+''');
+    return prepareHover('p) {').then((HoverInformation hover) {
+      // element
+      expect(hover.containingLibraryName, isNull);
+      expect(hover.containingLibraryPath, isNull);
+      expect(hover.containingClassDescription, isNull);
+      expect(hover.dartdoc, 'The method documentation.');
+      expect(hover.elementDescription, 'int p');
+      expect(hover.elementKind, 'parameter');
+      // types
+      expect(hover.staticType, 'int');
+      expect(hover.propagatedType, isNull);
+      // no parameter
+      expect(hover.parameter, isNull);
+    });
+  }
+
   test_expression_syntheticGetter() {
     addTestFile('''
 library my.library;
 class A {
   /// doc aaa
   /// doc bbb
   String fff;
 }
 main(A a) {
   print(a.fff);
@@ skipping 151 matching lines @@
 library my.library;
 main() {
   // nothing
 }
 ''');
     return prepareHover('nothing').then((HoverInformation hover) {
       expect(hover, isNull);
     });
   }
 }