Implement 'topLevelLibraryDeclarations' getter to return all libraries with exported top-level decl…

pkg/analyzer/test/src/dart/analysis/driver_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.
 
 library analyzer.test.driver;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/dart/analysis/byte_store.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
 import 'package:analyzer/src/dart/analysis/file_state.dart';
 import 'package:analyzer/src/dart/analysis/status.dart';
+import 'package:analyzer/src/dart/analysis/top_level_declaration.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart' show AnalysisOptionsImpl;
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/summary/idl.dart';
 import 'package:convert/convert.dart';
 import 'package:crypto/crypto.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../context/mock_sdk.dart';
@@ skipping 1101 matching lines @@
     addTestFile('int f() => 42;');
     await _waitForIdle();
 
     expect(allStatuses, hasLength(2));
     expect(allStatuses[0].isAnalyzing, isTrue);
     expect(allStatuses[0].isIdle, isFalse);
     expect(allStatuses[1].isAnalyzing, isFalse);
     expect(allStatuses[1].isIdle, isTrue);
   }
 
+  test_topLevelLibraryDeclarations() async {
+    var a = _p('/test/lib/a.dart');
+    var b = _p('/test/lib/b.dart');
+    var c = _p('/test/lib/c.dart');
+    var d = _p('/test/lib/d.dart');
+
+    provider.newFile(a, 'class A {}');
+    provider.newFile(b, 'export "a.dart", class B {}');
+    provider.newFile(c, 'import "d.dart"; class C {}');
+    provider.newFile(d, 'class D {}');
+
+    driver.addFile(a);
+    driver.addFile(b);
+    driver.addFile(c);
+    // Don't add d.dart, it is referenced implicitly.
+
+    List<TopLevelLibraryDeclarations> libraries =
+        await driver.topLevelLibraryDeclarations;
+    expect(libraries, hasLength(4));
+
+    void assertDeclarations(String path, List<String> expectedNames) {
+      TopLevelLibraryDeclarations library =
+          libraries.singleWhere((l) => l.source.fullName == path);
+      expect(library.declarations.map((d) => d.name),
+          unorderedEquals(expectedNames));
+    }
+
+    assertDeclarations(a, ['A']);
+    assertDeclarations(b, ['A', 'B']);
+    assertDeclarations(c, ['C']);
+    assertDeclarations(d, ['D']);
+  }
+
   ClassDeclaration _getClass(CompilationUnit unit, String name) {
     for (CompilationUnitMember declaration in unit.declarations) {
       if (declaration is ClassDeclaration) {
         if (declaration.name.name == name) {
           return declaration;
         }
       }
     }
     fail('Cannot find the class $name in\n$unit');
     return null;
@@ skipping 76 matching lines @@
   String _p(String path) => provider.convertPath(path);
 
   Future<Null> _waitForIdle() async {
     await idleStatusMonitor.signal;
   }
 
   static String _md5(String content) {
     return hex.encode(md5.convert(UTF8.encode(content)).bytes);
   }
 }