Implement search for PrefixElement.

pkg/analyzer/test/src/dart/analysis/search_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 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/dart/analysis/search.dart';
@@ skipping 20 matching lines @@
 
   ExpectedResult(this.enclosingElement, this.kind, this.offset, this.length,
       {this.isResolved: true, this.isQualified: false});
 
   bool operator ==(Object result) {
     return result is SearchResult &&
         result.kind == this.kind &&
         result.isResolved == this.isResolved &&
         result.isQualified == this.isQualified &&
         result.offset == this.offset &&
+        result.length == this.length &&
         result.enclosingElement == this.enclosingElement;
   }
 
   @override
   String toString() {
     StringBuffer buffer = new StringBuffer();
     buffer.write("ExpectedResult(kind=");
     buffer.write(kind);
     buffer.write(", enclosingElement=");
     buffer.write(enclosingElement);
@@ skipping 452 matching lines @@
     var expected = [
       _expectId(fooElement, SearchResultKind.WRITE, 'p = 1;'),
       _expectId(fooElement, SearchResultKind.READ_WRITE, 'p += 2;'),
       _expectId(fooElement, SearchResultKind.READ, 'p);'),
       _expectId(fooElement, SearchResultKind.INVOCATION, 'p();'),
       _expectIdQ(mainElement, SearchResultKind.REFERENCE, 'p: 42')
     ];
     await _verifyReferences(element, expected);
   }
 
+  test_searchReferences_PrefixElement() async {
+    String partCode = r'''
+part of my_lib;
+ppp.Future c;
+''';
+    provider.newFile(_p('$testProject/my_part.dart'), partCode);
+    await _resolveTestUnit('''
+library my_lib;
+import 'dart:async' as ppp;
+part 'my_part.dart';
+main() {
+  ppp.Future a;
+  ppp.Stream b;
+}
+''');
+    PrefixElement element = _findElementAtString('ppp;');
+    Element a = _findElement('a');
+    Element b = _findElement('b');
+    Element c = findChildElement(testLibraryElement, 'c');
+    var expected = [
+      _expectId(a, SearchResultKind.REFERENCE, 'ppp.Future'),
+      _expectId(b, SearchResultKind.REFERENCE, 'ppp.Stream'),
+      new ExpectedResult(c, SearchResultKind.REFERENCE,
+          partCode.indexOf('ppp.Future c'), 'ppp'.length)
+    ];
+    await _verifyReferences(element, expected);
+  }
+
   test_searchReferences_PropertyAccessorElement_getter() async {
     await _resolveTestUnit('''
 class A {
   get ggg => null;
   main() {
     print(ggg); // ref-nq
     print(this.ggg); // ref-q
     ggg(); // inv-nq
     this.ggg(); // inv-q
   }
@@ skipping 177 matching lines @@
     List<SearchResult> results = await driver.search.references(element);
     _assertResults(results, expectedMatches);
     expect(results, hasLength(expectedMatches.length));
   }
 
   static void _assertResults(
       List<SearchResult> matches, List<ExpectedResult> expectedMatches) {
     expect(matches, unorderedEquals(expectedMatches));
   }
 }