pkg/analysis_server/test/context_manager_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.context.directory.manager;

import 'dart:collection';

import 'package:analysis_server/src/context_manager.dart';
import 'package:analysis_server/src/source/optimizing_pub_package_map_provider.dart';
import 'package:analysis_server/uri/resolver_provider.dart';
import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/file_system/memory_file_system.dart';
import 'package:analyzer/instrumentation/instrumentation.dart';
import 'package:analyzer/source/package_map_resolver.dart';
import 'package:analyzer/src/generated/engine.dart';
import 'package:analyzer/src/generated/source.dart';
import 'package:analyzer/src/generated/source_io.dart';
import 'package:package_config/packages.dart';
import 'package:path/path.dart';
import 'package:test_reflective_loader/test_reflective_loader.dart';
import 'package:unittest/unittest.dart';

import 'mocks.dart';

main() {
  groupSep = ' | ';
  defineReflectiveTests(AbstractContextManagerTest);
}

@reflectiveTest
class AbstractContextManagerTest {
  /**
   * The name of the 'bin' directory.
   */
  static const String BIN_NAME = 'bin';

  /**
   * The name of the 'example' directory.
   */
  static const String EXAMPLE_NAME = 'example';

  /**
   * The name of the 'lib' directory.
   */
  static const String LIB_NAME = 'lib';

  /**
   * The name of the 'src' directory.
   */
  static const String SRC_NAME = 'src';

  /**
   * The name of the 'test' directory.
   */
  static const String TEST_NAME = 'test';

  TestContextManager manager;

  MemoryResourceProvider resourceProvider;

  MockPackageMapProvider packageMapProvider;

  UriResolver packageResolver = null;

  String projPath = '/my/proj';

  String newFile(List<String> pathComponents, [String content = '']) {
    String filePath = posix.joinAll(pathComponents);
    resourceProvider.newFile(filePath, content);
    return filePath;
  }

  String newFolder(List<String> pathComponents) {
    String folderPath = posix.joinAll(pathComponents);
    resourceProvider.newFolder(folderPath);
    return folderPath;
  }

  UriResolver providePackageResolver(Folder folder) {
    return packageResolver;
  }

  void setUp() {
    resourceProvider = new MemoryResourceProvider();
    packageMapProvider = new MockPackageMapProvider();
    manager = new TestContextManager(
        resourceProvider, providePackageResolver, packageMapProvider);
    resourceProvider.newFolder(projPath);
    AbstractContextManager.ENABLE_PACKAGESPEC_SUPPORT = true;
  }

  void tearDown() {
    AbstractContextManager.ENABLE_PACKAGESPEC_SUPPORT = false;
  }

  test_ignoreFilesInPackagesFolder() {
    // create a context with a pubspec.yaml file
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    resourceProvider.newFile(pubspecPath, 'pubspec');
    // create a file in the "packages" folder
    String filePath1 = posix.join(projPath, 'packages', 'file1.dart');
    resourceProvider.newFile(filePath1, 'contents');
    // "packages" files are ignored initially
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.currentContextFilePaths[projPath], isEmpty);
    // "packages" files are ignored during watch
    String filePath2 = posix.join(projPath, 'packages', 'file2.dart');
    resourceProvider.newFile(filePath2, 'contents');
    return pumpEventQueue().then((_) {
      expect(manager.currentContextFilePaths[projPath], isEmpty);
    });
  }

  void test_isInAnalysisRoot_excluded() {
    // prepare paths
    String project = '/project';
    String excludedFolder = '$project/excluded';
    // set roots
    resourceProvider.newFolder(project);
    resourceProvider.newFolder(excludedFolder);
    manager.setRoots(
        <String>[project], <String>[excludedFolder], <String, String>{});
    // verify
    expect(manager.isInAnalysisRoot('$excludedFolder/test.dart'), isFalse);
  }

  void test_isInAnalysisRoot_inRoot() {
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.isInAnalysisRoot('$projPath/test.dart'), isTrue);
  }

  void test_isInAnalysisRoot_notInRoot() {
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.isInAnalysisRoot('/test.dart'), isFalse);
  }

  test_refresh_folder_with_packagespec() {
    // create a context with a .packages file
    String packagespecFile = posix.join(projPath, '.packages');
    resourceProvider.newFile(packagespecFile, '');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    return pumpEventQueue().then((_) {
      expect(manager.currentContextPaths.toList(), [projPath]);
      manager.now++;
      manager.refresh(null);
      return pumpEventQueue().then((_) {
        expect(manager.currentContextPaths.toList(), [projPath]);
        expect(manager.currentContextTimestamps[projPath], manager.now);
      });
    });
  }

  test_refresh_folder_with_packagespec_subfolders() {
    // Create a folder with no .packages file, containing two subfolders with
    // .packages files.
    String subdir1Path = posix.join(projPath, 'subdir1');
    String subdir2Path = posix.join(projPath, 'subdir2');
    String packagespec1Path = posix.join(subdir1Path, '.packages');
    String packagespec2Path = posix.join(subdir2Path, '.packages');
    resourceProvider.newFile(packagespec1Path, '');
    resourceProvider.newFile(packagespec2Path, '');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    return pumpEventQueue().then((_) {
      expect(manager.currentContextPaths.toSet(),
          [subdir1Path, subdir2Path, projPath].toSet());
      manager.now++;
      manager.refresh(null);
      return pumpEventQueue().then((_) {
        expect(manager.currentContextPaths.toSet(),
            [subdir1Path, subdir2Path, projPath].toSet());
        expect(manager.currentContextTimestamps[projPath], manager.now);
        expect(manager.currentContextTimestamps[subdir1Path], manager.now);
        expect(manager.currentContextTimestamps[subdir2Path], manager.now);
      });
    });
  }

  test_refresh_folder_with_pubspec() {
    // create a context with a pubspec.yaml file
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    resourceProvider.newFile(pubspecPath, 'pubspec');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    return pumpEventQueue().then((_) {
      expect(manager.currentContextPaths.toList(), [projPath]);
      manager.now++;
      manager.refresh(null);
      return pumpEventQueue().then((_) {
        expect(manager.currentContextPaths.toList(), [projPath]);
        expect(manager.currentContextTimestamps[projPath], manager.now);
      });
    });
  }

  test_refresh_folder_with_pubspec_subfolders() {
    // Create a folder with no pubspec.yaml, containing two subfolders with
    // pubspec.yaml files.
    String subdir1Path = posix.join(projPath, 'subdir1');
    String subdir2Path = posix.join(projPath, 'subdir2');
    String pubspec1Path = posix.join(subdir1Path, 'pubspec.yaml');
    String pubspec2Path = posix.join(subdir2Path, 'pubspec.yaml');
    resourceProvider.newFile(pubspec1Path, 'pubspec');
    resourceProvider.newFile(pubspec2Path, 'pubspec');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    return pumpEventQueue().then((_) {
      expect(manager.currentContextPaths.toSet(),
          [subdir1Path, subdir2Path, projPath].toSet());
      manager.now++;
      manager.refresh(null);
      return pumpEventQueue().then((_) {
        expect(manager.currentContextPaths.toSet(),
            [subdir1Path, subdir2Path, projPath].toSet());
        expect(manager.currentContextTimestamps[projPath], manager.now);
        expect(manager.currentContextTimestamps[subdir1Path], manager.now);
        expect(manager.currentContextTimestamps[subdir2Path], manager.now);
      });
    });
  }

  test_path_filter() async {
    // Setup context.
    Folder root = resourceProvider.newFolder(projPath);
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.currentContextFilePaths[projPath], isEmpty);
    // Set ignore patterns for context.
    manager.setIgnorePatternsForContext(
        root, ['sdk_ext/**', 'lib/ignoreme.dart']);
    // Start creating files.
    newFile([projPath, AbstractContextManager.PUBSPEC_NAME]);
    String libPath = newFolder([projPath, LIB_NAME]);
    newFile([libPath, 'main.dart']);
    newFile([libPath, 'ignoreme.dart']);
    String sdkExtPath = newFolder([projPath, 'sdk_ext']);
    newFile([sdkExtPath, 'entry.dart']);
    String sdkExtSrcPath = newFolder([projPath, 'sdk_ext', 'src']);
    newFile([sdkExtSrcPath, 'part.dart']);
    // Pump event loop so new files are discovered and added to context.
    await pumpEventQueue();
    // Verify that ignored files were ignored.
    Map<String, int> fileTimestamps = manager.currentContextFilePaths[projPath];
    expect(fileTimestamps, isNotEmpty);
    List<String> files = fileTimestamps.keys.toList();
    expect(files.length, equals(1));
    expect(files[0], equals('/my/proj/lib/main.dart'));
  }

  test_path_filter_analysis_option() async {
    // Create files.
    String libPath = newFolder([projPath, LIB_NAME]);
    newFile([libPath, 'main.dart']);
    newFile([libPath, 'nope.dart']);
    String sdkExtPath = newFolder([projPath, 'sdk_ext']);
    newFile([sdkExtPath, 'entry.dart']);
    String sdkExtSrcPath = newFolder([projPath, 'sdk_ext', 'src']);
    newFile([sdkExtSrcPath, 'part.dart']);
    // Setup analysis options file with ignore list.
    newFile([projPath, '.analysis_options'], r'''
analyzer:
  exclude:
    - lib/nope.dart
    - 'sdk_ext/**'
''');
    // Setup context.
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // Verify that analysis options was parsed and the ignore patterns applied.
    Map<String, int> fileTimestamps = manager.currentContextFilePaths[projPath];
    expect(fileTimestamps, isNotEmpty);
    List<String> files = fileTimestamps.keys.toList();
    expect(files.length, equals(1));
    expect(files[0], equals('/my/proj/lib/main.dart'));
  }

  test_refresh_oneContext() {
    // create two contexts with pubspec.yaml files
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    resourceProvider.newFile(pubspecPath, 'pubspec1');

    String proj2Path = '/my/proj2';
    resourceProvider.newFolder(proj2Path);
    String pubspec2Path = posix.join(proj2Path, 'pubspec.yaml');
    resourceProvider.newFile(pubspec2Path, 'pubspec2');

    List<String> roots = <String>[projPath, proj2Path];
    manager.setRoots(roots, <String>[], <String, String>{});
    return pumpEventQueue().then((_) {
      expect(manager.currentContextPaths.toList(), unorderedEquals(roots));
      int then = manager.now;
      manager.now++;
      manager.refresh([resourceProvider.getResource(proj2Path)]);
      return pumpEventQueue().then((_) {
        expect(manager.currentContextPaths.toList(), unorderedEquals(roots));
        expect(manager.currentContextTimestamps[projPath], then);
        expect(manager.currentContextTimestamps[proj2Path], manager.now);
      });
    });
  }

  void test_setRoots_addFolderWithDartFile() {
    String filePath = posix.join(projPath, 'foo.dart');
    resourceProvider.newFile(filePath, 'contents');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    var filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
    List<AnalysisContext> contextsInAnalysisRoot =
        manager.contextsInAnalysisRoot(resourceProvider.newFolder(projPath));
    expect(contextsInAnalysisRoot, hasLength(1));
    AnalysisContext context = contextsInAnalysisRoot[0];
    expect(context, isNotNull);
    Source result = context.sourceFactory.forUri('package:foo/foo.dart');
    expect(result, isNotNull);
    expect(result.exists(), isFalse);
  }

  void test_setRoots_addFolderWithDartFileInSubfolder() {
    String filePath = posix.join(projPath, 'foo', 'bar.dart');
    resourceProvider.newFile(filePath, 'contents');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    var filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
  }

  void test_setRoots_addFolderWithDummyLink() {
    String filePath = posix.join(projPath, 'foo.dart');
    resourceProvider.newDummyLink(filePath);
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    var filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, isEmpty);
  }

  void test_setRoots_addFolderWithNestedPackageSpec() {
    String examplePath = newFolder([projPath, EXAMPLE_NAME]);
    String libPath = newFolder([projPath, LIB_NAME]);

    newFile([projPath, AbstractContextManager.PACKAGE_SPEC_NAME]);
    newFile([libPath, 'main.dart']);
    newFile([examplePath, AbstractContextManager.PACKAGE_SPEC_NAME]);
    newFile([examplePath, 'example.dart']);

    packageMapProvider.packageMap['proj'] =
        [resourceProvider.getResource(libPath)];

    manager.setRoots(<String>[projPath], <String>[], <String, String>{});

    expect(manager.currentContextPaths, hasLength(2));

    expect(manager.currentContextPaths, contains(projPath));
    Set<Source> projSources = manager.currentContextSources[projPath];
    expect(projSources, hasLength(1));
    expect(projSources.first.uri.toString(), 'file:///my/proj/lib/main.dart');

    expect(manager.currentContextPaths, contains(examplePath));
    Set<Source> exampleSources = manager.currentContextSources[examplePath];
    expect(exampleSources, hasLength(1));
    expect(exampleSources.first.uri.toString(),
        'file:///my/proj/example/example.dart');
  }

  void test_setRoots_addFolderWithNestedPubspec() {
    String examplePath = newFolder([projPath, EXAMPLE_NAME]);
    String libPath = newFolder([projPath, LIB_NAME]);

    newFile([projPath, AbstractContextManager.PUBSPEC_NAME]);
    newFile([libPath, 'main.dart']);
    newFile([examplePath, AbstractContextManager.PUBSPEC_NAME]);
    newFile([examplePath, 'example.dart']);

    packageMapProvider.packageMap['proj'] =
        [resourceProvider.getResource(libPath)];

    manager.setRoots(<String>[projPath], <String>[], <String, String>{});

    expect(manager.currentContextPaths, hasLength(2));

    expect(manager.currentContextPaths, contains(projPath));
    Set<Source> projSources = manager.currentContextSources[projPath];
    expect(projSources, hasLength(1));
    expect(projSources.first.uri.toString(), 'package:proj/main.dart');

    expect(manager.currentContextPaths, contains(examplePath));
    Set<Source> exampleSources = manager.currentContextSources[examplePath];
    expect(exampleSources, hasLength(1));
    expect(exampleSources.first.uri.toString(),
        'file:///my/proj/example/example.dart');
  }

  void test_setRoots_addFolderWithoutPubspec() {
    packageMapProvider.packageMap = null;
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    expect(manager.currentContextPaths, hasLength(1));
    expect(manager.currentContextPaths, contains(projPath));
    expect(manager.currentContextFilePaths[projPath], hasLength(0));
  }

  void test_setRoots_addFolderWithPackagespec() {
    String packagespecPath = posix.join(projPath, '.packages');
    resourceProvider.newFile(packagespecPath,
        'unittest:file:///home/somebody/.pub/cache/unittest-0.9.9/lib/');
    String libPath = newFolder([projPath, LIB_NAME]);
    File mainFile =
        resourceProvider.newFile(posix.join(libPath, 'main.dart'), '');
    Source source = mainFile.createSource();

    manager.setRoots(<String>[projPath], <String>[], <String, String>{});

    // verify
    expect(manager.currentContextPaths, hasLength(1));
    expect(manager.currentContextPaths, contains(projPath));
    expect(manager.currentContextFilePaths[projPath], hasLength(1));

    // smoketest resolution
    SourceFactory sourceFactory = manager.currentContext.sourceFactory;
    Source resolvedSource =
        sourceFactory.resolveUri(source, 'package:unittest/unittest.dart');
    expect(resolvedSource, isNotNull);
    expect(resolvedSource.fullName,
        equals('/home/somebody/.pub/cache/unittest-0.9.9/lib/unittest.dart'));
  }

  void test_setRoots_addFolderWithPubspec() {
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    resourceProvider.newFile(pubspecPath, 'pubspec');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    expect(manager.currentContextPaths, hasLength(1));
    expect(manager.currentContextPaths, contains(projPath));
    expect(manager.currentContextFilePaths[projPath], hasLength(0));
  }

  void test_setRoots_addFolderWithPubspec_andPackagespec() {
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    String packagespecPath = posix.join(projPath, '.packages');
    resourceProvider.newFile(pubspecPath, 'pubspec');
    resourceProvider.newFile(packagespecPath, '');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // verify
    manager.assertContextPaths([projPath]);
  }

  void test_setRoots_addFolderWithPubspecAndLib() {
    String binPath = newFolder([projPath, BIN_NAME]);
    String libPath = newFolder([projPath, LIB_NAME]);
    String srcPath = newFolder([libPath, SRC_NAME]);
    String testPath = newFolder([projPath, TEST_NAME]);

    newFile([projPath, AbstractContextManager.PUBSPEC_NAME]);
    String appPath = newFile([binPath, 'app.dart']);
    newFile([libPath, 'main.dart']);
    newFile([srcPath, 'internal.dart']);
    String testFilePath = newFile([testPath, 'main_test.dart']);

    packageMapProvider.packageMap['proj'] =
        [resourceProvider.getResource(libPath)];

    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    Set<Source> sources = manager.currentContextSources[projPath];

    expect(manager.currentContextPaths, hasLength(1));
    expect(manager.currentContextPaths, contains(projPath));
    expect(sources, hasLength(4));
    List<String> uris =
        sources.map((Source source) => source.uri.toString()).toList();
    expect(uris, contains('file://$appPath'));
    expect(uris, contains('package:proj/main.dart'));
    expect(uris, contains('package:proj/src/internal.dart'));
    expect(uris, contains('file://$testFilePath'));
  }

  void test_setRoots_addFolderWithPubspecAndPackagespecFolders() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProjectA = '$root/sub/aaa';
    String subProjectB = '$root/sub/sub2/bbb';
    String subProjectA_file = '$subProjectA/bin/a.dart';
    String subProjectB_file = '$subProjectB/bin/b.dart';
    // create files
    resourceProvider.newFile('$subProjectA/pubspec.yaml', 'pubspec');
    resourceProvider.newFile('$subProjectB/pubspec.yaml', 'pubspec');
    resourceProvider.newFile('$subProjectA/.packages', '');
    resourceProvider.newFile('$subProjectB/.packages', '');

    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subProjectA_file, 'library a;');
    resourceProvider.newFile(subProjectB_file, 'library b;');

    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProjectA, subProjectB]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
    manager.assertContextFiles(subProjectB, [subProjectB_file]);
  }

  void test_setRoots_addFolderWithPubspecFolders() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProjectA = '$root/sub/aaa';
    String subProjectB = '$root/sub/sub2/bbb';
    String subProjectA_file = '$subProjectA/bin/a.dart';
    String subProjectB_file = '$subProjectB/bin/b.dart';
    // create files
    resourceProvider.newFile('$subProjectA/pubspec.yaml', 'pubspec');
    resourceProvider.newFile('$subProjectB/pubspec.yaml', 'pubspec');
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subProjectA_file, 'library a;');
    resourceProvider.newFile(subProjectB_file, 'library b;');
    // configure package maps
    packageMapProvider.packageMaps = {
      subProjectA: {'foo': [resourceProvider.newFolder('/package/foo')]},
      subProjectB: {'bar': [resourceProvider.newFolder('/package/bar')]},
    };
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProjectA, subProjectB]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
    manager.assertContextFiles(subProjectB, [subProjectB_file]);
    // verify package maps
    _checkPackageMap(root, isNull);
    _checkPackageMap(
        subProjectA, equals(packageMapProvider.packageMaps[subProjectA]));
    _checkPackageMap(
        subProjectB, equals(packageMapProvider.packageMaps[subProjectB]));
  }

  void test_setRoots_addPackageRoot() {
    String packagePathFoo = '/package1/foo';
    String packageRootPath = '/package2/foo';
    Folder packageFolder = resourceProvider.newFolder(packagePathFoo);
    packageMapProvider.packageMap = {'foo': [packageFolder]};
    List<String> includedPaths = <String>[projPath];
    List<String> excludedPaths = <String>[];
    manager.setRoots(includedPaths, excludedPaths, <String, String>{});
    _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
    manager.setRoots(includedPaths, excludedPaths, <String, String>{
      projPath: packageRootPath
    });
    _checkPackageRoot(projPath, equals(packageRootPath));
  }

  void test_setRoots_changePackageRoot() {
    String packageRootPath1 = '/package1';
    String packageRootPath2 = '/package2';
    List<String> includedPaths = <String>[projPath];
    List<String> excludedPaths = <String>[];
    manager.setRoots(includedPaths, excludedPaths, <String, String>{
      projPath: packageRootPath1
    });
    _checkPackageRoot(projPath, equals(packageRootPath1));
    manager.setRoots(includedPaths, excludedPaths, <String, String>{
      projPath: packageRootPath2
    });
    _checkPackageRoot(projPath, equals(packageRootPath2));
  }

  void test_setRoots_exclude_newRoot_withExcludedFile() {
    // prepare paths
    String project = '/project';
    String file1 = '$project/file1.dart';
    String file2 = '$project/file2.dart';
    // create files
    resourceProvider.newFile(file1, '// 1');
    resourceProvider.newFile(file2, '// 2');
    // set roots
    manager.setRoots(<String>[project], <String>[file1], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file2]);
  }

  void test_setRoots_exclude_newRoot_withExcludedFolder() {
    // prepare paths
    String project = '/project';
    String folderA = '$project/aaa';
    String folderB = '$project/bbb';
    String fileA = '$folderA/a.dart';
    String fileB = '$folderB/b.dart';
    // create files
    resourceProvider.newFile(fileA, 'library a;');
    resourceProvider.newFile(fileB, 'library b;');
    // set roots
    manager.setRoots(<String>[project], <String>[folderB], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA]);
  }

  void test_setRoots_exclude_sameRoot_addExcludedFile() {
    // prepare paths
    String project = '/project';
    String file1 = '$project/file1.dart';
    String file2 = '$project/file2.dart';
    // create files
    resourceProvider.newFile(file1, '// 1');
    resourceProvider.newFile(file2, '// 2');
    // set roots
    manager.setRoots(<String>[project], <String>[], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1, file2]);
    // exclude "2"
    manager.setRoots(<String>[project], <String>[file2], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1]);
  }

  void test_setRoots_exclude_sameRoot_addExcludedFolder() {
    // prepare paths
    String project = '/project';
    String folderA = '$project/aaa';
    String folderB = '$project/bbb';
    String fileA = '$folderA/a.dart';
    String fileB = '$folderB/b.dart';
    // create files
    resourceProvider.newFile(fileA, 'library a;');
    resourceProvider.newFile(fileB, 'library b;');
    // initially both "aaa/a" and "bbb/b" are included
    manager.setRoots(<String>[project], <String>[], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA, fileB]);
    // exclude "bbb/"
    manager.setRoots(<String>[project], <String>[folderB], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA]);
  }

  void test_setRoots_exclude_sameRoot_removeExcludedFile() {
    // prepare paths
    String project = '/project';
    String file1 = '$project/file1.dart';
    String file2 = '$project/file2.dart';
    // create files
    resourceProvider.newFile(file1, '// 1');
    resourceProvider.newFile(file2, '// 2');
    // set roots
    manager.setRoots(<String>[project], <String>[file2], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1]);
    // stop excluding "2"
    manager.setRoots(<String>[project], <String>[], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1, file2]);
  }

  void test_setRoots_exclude_sameRoot_removeExcludedFile_inFolder() {
    // prepare paths
    String project = '/project';
    String file1 = '$project/bin/file1.dart';
    String file2 = '$project/bin/file2.dart';
    // create files
    resourceProvider.newFile(file1, '// 1');
    resourceProvider.newFile(file2, '// 2');
    // set roots
    manager.setRoots(<String>[project], <String>[file2], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1]);
    // stop excluding "2"
    manager.setRoots(<String>[project], <String>[], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [file1, file2]);
  }

  void test_setRoots_exclude_sameRoot_removeExcludedFolder() {
    // prepare paths
    String project = '/project';
    String folderA = '$project/aaa';
    String folderB = '$project/bbb';
    String fileA = '$folderA/a.dart';
    String fileB = '$folderB/b.dart';
    // create files
    resourceProvider.newFile(fileA, 'library a;');
    resourceProvider.newFile(fileB, 'library b;');
    // exclude "bbb/"
    manager.setRoots(<String>[project], <String>[folderB], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA]);
    // stop excluding "bbb/"
    manager.setRoots(<String>[project], <String>[], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA, fileB]);
  }

  void test_setRoots_newFolderWithPackageRoot() {
    String packageRootPath = '/package';
    manager.setRoots(<String>[projPath], <String>[], <String, String>{
      projPath: packageRootPath
    });
    _checkPackageRoot(projPath, equals(packageRootPath));
  }

  void test_setRoots_newlyAddedFoldersGetProperPackageMap() {
    String packagePath = '/package/foo';
    Folder packageFolder = resourceProvider.newFolder(packagePath);
    packageMapProvider.packageMap = {'foo': [packageFolder]};
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
  }

  void test_setRoots_packageResolver() {
    Uri uri = Uri.parse('package:foo/foo.dart');
    Source source = new TestSource();
    packageResolver = new TestUriResolver({uri: source});
    String filePath = posix.join(projPath, 'foo.dart');
    resourceProvider.newFile(filePath, 'contents');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});

    List<AnalysisContext> contextsInAnalysisRoot =
        manager.contextsInAnalysisRoot(resourceProvider.newFolder(projPath));
    expect(contextsInAnalysisRoot, hasLength(1));
    AnalysisContext context = contextsInAnalysisRoot[0];
    expect(context, isNotNull);
    Source result = context.sourceFactory.forUri2(uri);
    expect(result, same(source));
  }

  void test_setRoots_removeFolderWithoutPubspec() {
    packageMapProvider.packageMap = null;
    // add one root - there is a context
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(1));
    // set empty roots - no contexts
    manager.setRoots(<String>[], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(0));
    expect(manager.currentContextFilePaths, hasLength(0));
  }

  void test_setRoots_removeFolderWithPackagespec() {
    // create a pubspec
    String pubspecPath = posix.join(projPath, '.packages');
    resourceProvider.newFile(pubspecPath, '');
    // add one root - there is a context
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(1));
    // set empty roots - no contexts
    manager.setRoots(<String>[], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(0));
    expect(manager.currentContextFilePaths, hasLength(0));
  }

  void test_setRoots_removeFolderWithPackagespecFolder() {
    // prepare paths
    String projectA = '/projectA';
    String projectB = '/projectB';
    String subProjectA = '$projectA/sub';
    String subProjectB = '$projectB/sub';
    String projectA_file = '$projectA/a.dart';
    String projectB_file = '$projectB/a.dart';
    String subProjectA_pubspec = '$subProjectA/.packages';
    String subProjectB_pubspec = '$subProjectB/.packages';
    String subProjectA_file = '$subProjectA/bin/sub_a.dart';
    String subProjectB_file = '$subProjectB/bin/sub_b.dart';
    // create files
    resourceProvider.newFile(projectA_file, '// a');
    resourceProvider.newFile(projectB_file, '// b');
    resourceProvider.newFile(subProjectA_pubspec, '');
    resourceProvider.newFile(subProjectB_pubspec, '');
    resourceProvider.newFile(subProjectA_file, '// sub-a');
    resourceProvider.newFile(subProjectB_file, '// sub-b');
    // set roots
    manager.setRoots(
        <String>[projectA, projectB], <String>[], <String, String>{});
    manager.assertContextPaths([projectA, subProjectA, projectB, subProjectB]);
    manager.assertContextFiles(projectA, [projectA_file]);
    manager.assertContextFiles(projectB, [projectB_file]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
    manager.assertContextFiles(subProjectB, [subProjectB_file]);
    // remove "projectB"
    manager.setRoots(<String>[projectA], <String>[], <String, String>{});
    manager.assertContextPaths([projectA, subProjectA]);
    manager.assertContextFiles(projectA, [projectA_file]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
  }

  void test_setRoots_removeFolderWithPubspec() {
    // create a pubspec
    String pubspecPath = posix.join(projPath, 'pubspec.yaml');
    resourceProvider.newFile(pubspecPath, 'pubspec');
    // add one root - there is a context
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(1));
    // set empty roots - no contexts
    manager.setRoots(<String>[], <String>[], <String, String>{});
    expect(manager.currentContextPaths, hasLength(0));
    expect(manager.currentContextFilePaths, hasLength(0));
  }

  void test_setRoots_removeFolderWithPubspecFolder() {
    // prepare paths
    String projectA = '/projectA';
    String projectB = '/projectB';
    String subProjectA = '$projectA/sub';
    String subProjectB = '$projectB/sub';
    String projectA_file = '$projectA/a.dart';
    String projectB_file = '$projectB/a.dart';
    String subProjectA_pubspec = '$subProjectA/pubspec.yaml';
    String subProjectB_pubspec = '$subProjectB/pubspec.yaml';
    String subProjectA_file = '$subProjectA/bin/sub_a.dart';
    String subProjectB_file = '$subProjectB/bin/sub_b.dart';
    // create files
    resourceProvider.newFile(projectA_file, '// a');
    resourceProvider.newFile(projectB_file, '// b');
    resourceProvider.newFile(subProjectA_pubspec, 'pubspec');
    resourceProvider.newFile(subProjectB_pubspec, 'pubspec');
    resourceProvider.newFile(subProjectA_file, '// sub-a');
    resourceProvider.newFile(subProjectB_file, '// sub-b');
    // set roots
    manager.setRoots(
        <String>[projectA, projectB], <String>[], <String, String>{});
    manager.assertContextPaths([projectA, subProjectA, projectB, subProjectB]);
    manager.assertContextFiles(projectA, [projectA_file]);
    manager.assertContextFiles(projectB, [projectB_file]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
    manager.assertContextFiles(subProjectB, [subProjectB_file]);
    // remove "projectB"
    manager.setRoots(<String>[projectA], <String>[], <String, String>{});
    manager.assertContextPaths([projectA, subProjectA]);
    manager.assertContextFiles(projectA, [projectA_file]);
    manager.assertContextFiles(subProjectA, [subProjectA_file]);
  }

  void test_setRoots_removePackageRoot() {
    String packagePathFoo = '/package1/foo';
    String packageRootPath = '/package2/foo';
    Folder packageFolder = resourceProvider.newFolder(packagePathFoo);
    packageMapProvider.packageMap = {'foo': [packageFolder]};
    List<String> includedPaths = <String>[projPath];
    List<String> excludedPaths = <String>[];
    manager.setRoots(includedPaths, excludedPaths, <String, String>{
      projPath: packageRootPath
    });
    _checkPackageRoot(projPath, equals(packageRootPath));
    manager.setRoots(includedPaths, excludedPaths, <String, String>{});
    _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
  }

  test_watch_addDummyLink() {
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // empty folder initially
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, isEmpty);
    // add link
    String filePath = posix.join(projPath, 'foo.dart');
    resourceProvider.newDummyLink(filePath);
    // the link was ignored
    return pumpEventQueue().then((_) {
      expect(filePaths, isEmpty);
    });
  }

  test_watch_addFile() {
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // empty folder initially
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(0));
    // add file
    String filePath = posix.join(projPath, 'foo.dart');
    resourceProvider.newFile(filePath, 'contents');
    // the file was added
    return pumpEventQueue().then((_) {
      expect(filePaths, hasLength(1));
      expect(filePaths, contains(filePath));
    });
  }

  test_watch_addFile_excluded() {
    // prepare paths
    String project = '/project';
    String folderA = '$project/aaa';
    String folderB = '$project/bbb';
    String fileA = '$folderA/a.dart';
    String fileB = '$folderB/b.dart';
    // create files
    resourceProvider.newFile(fileA, 'library a;');
    // set roots
    manager.setRoots(<String>[project], <String>[folderB], <String, String>{});
    manager.assertContextPaths([project]);
    manager.assertContextFiles(project, [fileA]);
    // add a file, ignored as excluded
    resourceProvider.newFile(fileB, 'library b;');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([project]);
      manager.assertContextFiles(project, [fileA]);
    });
  }

  test_watch_addFileInSubfolder() {
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // empty folder initially
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(0));
    // add file in subfolder
    String filePath = posix.join(projPath, 'foo', 'bar.dart');
    resourceProvider.newFile(filePath, 'contents');
    // the file was added
    return pumpEventQueue().then((_) {
      expect(filePaths, hasLength(1));
      expect(filePaths, contains(filePath));
    });
  }

  test_watch_addPackagespec_toRoot() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String rootPackagespec = '$root/.packages';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    // add packagespec - still just one root
    resourceProvider.newFile(rootPackagespec, '');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile]);
      // TODO(pquitslund): verify that a new source factory is created --
      // likely this will need to happen in a corresponding ServerContextManagerTest.
    });
  }

  test_watch_addPackagespec_toSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPubspec = '$subProject/.packages';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    // verify files
    manager.assertContextFiles(root, [rootFile, subFile]);
    // add .packages
    resourceProvider.newFile(subPubspec, '');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(root, [rootFile]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_addPackagespec_toSubFolder_ofSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub';
    String subPubspec = '$subProject/.packages';
    String subFile = '$subProject/bin/sub.dart';
    String subSubPubspec = '$subProject/subsub/.packages';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subPubspec, '');
    resourceProvider.newFile(subFile, 'library sub;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);
    // add pubspec - ignore, because is already in a packagespec-based context
    resourceProvider.newFile(subSubPubspec, '');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(root, [rootFile]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_addPackagespec_toSubFolder_withPubspec() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPackagespec = '$subProject/.packages';
    String subPubspec = '$subProject/pubspec.yaml';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(subPubspec, 'pubspec');
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);

    // add .packages
    resourceProvider.newFile(subPackagespec, '');
    return pumpEventQueue().then((_) {
      // Should NOT create another context.
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(root, [rootFile]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_addPubspec_toRoot() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String rootPubspec = '$root/pubspec.yaml';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    // add pubspec - still just one root
    resourceProvider.newFile(rootPubspec, 'pubspec');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile]);
    });
  }

  test_watch_addPubspec_toSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPubspec = '$subProject/pubspec.yaml';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    // verify files
    manager.assertContextFiles(root, [rootFile, subFile]);
    // add pubspec
    resourceProvider.newFile(subPubspec, 'pubspec');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(root, [rootFile]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_addPubspec_toSubFolder_ofSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub';
    String subPubspec = '$subProject/pubspec.yaml';
    String subFile = '$subProject/bin/sub.dart';
    String subSubPubspec = '$subProject/subsub/pubspec.yaml';
    // create files
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subPubspec, 'pubspec');
    resourceProvider.newFile(subFile, 'library sub;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);
    // add pubspec - ignore, because is already in a pubspec-based context
    resourceProvider.newFile(subSubPubspec, 'pubspec');
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(root, [rootFile]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_deleteFile() {
    String filePath = posix.join(projPath, 'foo.dart');
    // add root with a file
    File file = resourceProvider.newFile(filePath, 'contents');
    Folder projFolder = file.parent;
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // the file was added
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
    expect(file.exists, isTrue);
    expect(projFolder.exists, isTrue);
    // delete the file
    resourceProvider.deleteFile(filePath);
    return pumpEventQueue().then((_) {
      expect(file.exists, isFalse);
      expect(projFolder.exists, isTrue);
      return expect(filePaths, hasLength(0));
    });
  }

  test_watch_deleteFolder() {
    String filePath = posix.join(projPath, 'foo.dart');
    // add root with a file
    File file = resourceProvider.newFile(filePath, 'contents');
    Folder projFolder = file.parent;
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // the file was added
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
    expect(file.exists, isTrue);
    expect(projFolder.exists, isTrue);
    // delete the folder
    resourceProvider.deleteFolder(projPath);
    return pumpEventQueue().then((_) {
      expect(file.exists, isFalse);
      expect(projFolder.exists, isFalse);
      return expect(filePaths, hasLength(0));
    });
  }

  test_watch_deletePackagespec_fromRoot() {
    // prepare paths
    String root = '/root';
    String rootPubspec = '$root/.packages';
    String rootFile = '$root/root.dart';
    // create files
    resourceProvider.newFile(rootPubspec, '');
    resourceProvider.newFile(rootFile, 'library root;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    manager.assertContextFiles(root, [rootFile]);
    // delete the pubspec
    resourceProvider.deleteFile(rootPubspec);
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile]);
    });
  }

  test_watch_deletePackagespec_fromSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPubspec = '$subProject/.packages';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(subPubspec, '');
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);
    // delete the pubspec
    resourceProvider.deleteFile(subPubspec);
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile, subFile]);
    });
  }

  test_watch_deletePackagespec_fromSubFolder_withPubspec() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPackagespec = '$subProject/.packages';
    String subPubspec = '$subProject/pubspec.yaml';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(subPackagespec, '');
    resourceProvider.newFile(subPubspec, 'pubspec');
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);
    // delete the packagespec
    resourceProvider.deleteFile(subPackagespec);
    return pumpEventQueue().then((_) {
      // Should NOT merge
      manager.assertContextPaths([root, subProject]);
      manager.assertContextFiles(subProject, [subFile]);
    });
  }

  test_watch_deletePubspec_fromRoot() {
    // prepare paths
    String root = '/root';
    String rootPubspec = '$root/pubspec.yaml';
    String rootFile = '$root/root.dart';
    // create files
    resourceProvider.newFile(rootPubspec, 'pubspec');
    resourceProvider.newFile(rootFile, 'library root;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root]);
    manager.assertContextFiles(root, [rootFile]);
    // delete the pubspec
    resourceProvider.deleteFile(rootPubspec);
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile]);
    });
  }

  test_watch_deletePubspec_fromSubFolder() {
    // prepare paths
    String root = '/root';
    String rootFile = '$root/root.dart';
    String subProject = '$root/sub/aaa';
    String subPubspec = '$subProject/pubspec.yaml';
    String subFile = '$subProject/bin/a.dart';
    // create files
    resourceProvider.newFile(subPubspec, 'pubspec');
    resourceProvider.newFile(rootFile, 'library root;');
    resourceProvider.newFile(subFile, 'library a;');
    // set roots
    manager.setRoots(<String>[root], <String>[], <String, String>{});
    manager.assertContextPaths([root, subProject]);
    // verify files
    manager.assertContextFiles(root, [rootFile]);
    manager.assertContextFiles(subProject, [subFile]);
    // delete the pubspec
    resourceProvider.deleteFile(subPubspec);
    return pumpEventQueue().then((_) {
      manager.assertContextPaths([root]);
      manager.assertContextFiles(root, [rootFile, subFile]);
    });
  }

  test_watch_modifyFile() {
    String filePath = posix.join(projPath, 'foo.dart');
    // add root with a file
    resourceProvider.newFile(filePath, 'contents');
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    // the file was added
    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
    expect(filePaths[filePath], equals(manager.now));
    // update the file
    manager.now++;
    resourceProvider.modifyFile(filePath, 'new contents');
    return pumpEventQueue().then((_) {
      return expect(filePaths[filePath], equals(manager.now));
    });
  }

  test_watch_modifyPackageMapDependency() {
    // create a dependency file
    String dependencyPath = posix.join(projPath, 'dep');
    resourceProvider.newFile(dependencyPath, 'contents');
    packageMapProvider.dependencies.add(dependencyPath);
    // create a Dart file
    String dartFilePath = posix.join(projPath, 'main.dart');
    resourceProvider.newFile(dartFilePath, 'contents');
    // the created context has the expected empty package map
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    _checkPackageMap(projPath, isEmpty);
    // configure package map
    String packagePath = '/package/foo';
    resourceProvider.newFolder(packagePath);
    packageMapProvider.packageMap = {'foo': projPath};
    // Changing a .dart file in the project shouldn't cause a new
    // package map to be picked up.
    resourceProvider.modifyFile(dartFilePath, 'new contents');
    return pumpEventQueue().then((_) {
      _checkPackageMap(projPath, isEmpty);
      // However, changing the package map dependency should.
      resourceProvider.modifyFile(dependencyPath, 'new contents');
      return pumpEventQueue().then((_) {
        _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
      });
    });
  }

  test_watch_modifyPackageMapDependency_fail() {
    // create a dependency file
    String dependencyPath = posix.join(projPath, 'dep');
    resourceProvider.newFile(dependencyPath, 'contents');
    packageMapProvider.dependencies.add(dependencyPath);
    // create a Dart file
    String dartFilePath = posix.join(projPath, 'main.dart');
    resourceProvider.newFile(dartFilePath, 'contents');
    // the created context has the expected empty package map
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    _checkPackageMap(projPath, isEmpty);
    // Change the package map dependency so that the packageMapProvider is
    // re-run, and arrange for it to return null from computePackageMap().
    packageMapProvider.packageMap = null;
    resourceProvider.modifyFile(dependencyPath, 'new contents');
    return pumpEventQueue().then((_) {
      // The package map should have been changed to null.
      _checkPackageMap(projPath, isNull);
    });
  }

  test_watch_modifyPackageMapDependency_outsideProject() {
    // create a dependency file
    String dependencyPath = '/my/other/dep';
    resourceProvider.newFile(dependencyPath, 'contents');
    packageMapProvider.dependencies.add(dependencyPath);
    // create a Dart file
    String dartFilePath = posix.join(projPath, 'main.dart');
    resourceProvider.newFile(dartFilePath, 'contents');
    // the created context has the expected empty package map
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    _checkPackageMap(projPath, isEmpty);
    // configure package map
    String packagePath = '/package/foo';
    resourceProvider.newFolder(packagePath);
    packageMapProvider.packageMap = {'foo': projPath};
    // Changing a .dart file in the project shouldn't cause a new
    // package map to be picked up.
    resourceProvider.modifyFile(dartFilePath, 'new contents');
    return pumpEventQueue().then((_) {
      _checkPackageMap(projPath, isEmpty);
      // However, changing the package map dependency should.
      resourceProvider.modifyFile(dependencyPath, 'new contents');
      return pumpEventQueue().then((_) {
        _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
      });
    });
  }

  test_watch_modifyPackageMapDependency_redundantly() async {
    // Create two dependency files
    String dependencyPath1 = posix.join(projPath, 'dep1');
    String dependencyPath2 = posix.join(projPath, 'dep2');
    resourceProvider.newFile(dependencyPath1, 'contents');
    resourceProvider.newFile(dependencyPath2, 'contents');
    packageMapProvider.dependencies.add(dependencyPath1);
    packageMapProvider.dependencies.add(dependencyPath2);
    // Create a dart file
    String dartFilePath = posix.join(projPath, 'main.dart');
    resourceProvider.newFile(dartFilePath, 'contents');
    // Verify that the created context has the expected empty package map.
    manager.setRoots(<String>[projPath], <String>[], <String, String>{});
    _checkPackageMap(projPath, isEmpty);
    expect(packageMapProvider.computeCount, 1);
    // Set up a different package map
    String packagePath = '/package/foo';
    resourceProvider.newFolder(packagePath);
    packageMapProvider.packageMap = {'foo': projPath};
    // Change both dependencies.
    resourceProvider.modifyFile(dependencyPath1, 'new contents');
    resourceProvider.modifyFile(dependencyPath2, 'new contents');
    // Arrange for the next call to computePackageMap to return the correct
    // timestamps for the dependencies.
    packageMapProvider.modificationTimes = <String, int>{};
    for (String path in [dependencyPath1, dependencyPath2]) {
      File resource = resourceProvider.getResource(path);
      packageMapProvider.modificationTimes[path] = resource.modificationStamp;
    }
    // This should cause the new package map to be picked up, by executing
    // computePackageMap just one additional time.
    await pumpEventQueue();
    _checkPackageMap(projPath, equals(packageMapProvider.packageMap));
    expect(packageMapProvider.computeCount, 2);
  }

  test_watch_modifyPackagespec() {
    String packagesPath = '$projPath/.packages';
    String filePath = '$projPath/bin/main.dart';

    resourceProvider.newFile(packagesPath, '');
    resourceProvider.newFile(filePath, 'library main;');

    manager.setRoots(<String>[projPath], <String>[], <String, String>{});

    Map<String, int> filePaths = manager.currentContextFilePaths[projPath];
    expect(filePaths, hasLength(1));
    expect(filePaths, contains(filePath));
    Packages packages = manager.currentContextPackagespecs[projPath];
    expect(packages.packages, isEmpty);

    // update .packages
    manager.now++;
    resourceProvider.modifyFile(packagesPath, 'main:./lib/');
    return pumpEventQueue().then((_) {
      // verify new package info
      packages = manager.currentContextPackagespecs[projPath];
      expect(packages.packages, unorderedEquals(['main']));
    });
  }

  /**
   * Verify that package URI's for source files in [path] will be resolved
   * using a package map matching [expectation].
   */
  void _checkPackageMap(String path, expectation) {
    UriResolver resolver = manager.currentContextPackageUriResolvers[path];
    Map<String, List<Folder>> packageMap =
        resolver is PackageMapUriResolver ? resolver.packageMap : null;
    expect(packageMap, expectation);
  }

  /**
   * Verify that package URI's for source files in [path] will be resolved
   * using a package root maching [expectation].
   */
  void _checkPackageRoot(String path, expectation) {
    UriResolver resolver = manager.currentContextPackageUriResolvers[path];
    expect(resolver, new isInstanceOf<PackageUriResolver>());
    PackageUriResolver packageUriResolver = resolver;
    expect(packageUriResolver.packagesDirectory_forTesting, expectation);
  }
}

class TestContextManager extends AbstractContextManager {
  /**
   * Source of timestamps stored in [currentContextFilePaths].
   */
  int now = 0;

  /**
   * The analysis context that was created.
   */
  AnalysisContext currentContext;

  /**
   * Map from context to the timestamp when the context was created.
   */
  Map<String, int> currentContextTimestamps = <String, int>{};

  /**
   * Map from context to (map from file path to timestamp of last event).
   */
  final Map<String, Map<String, int>> currentContextFilePaths =
      <String, Map<String, int>>{};

  /**
   * A map from the paths of contexts to a set of the sources that should be
   * explicitly analyzed in those contexts.
   */
  final Map<String, Set<Source>> currentContextSources = <String, Set<Source>>{
  };

  /**
   * Map from context to package URI resolver.
   */
  final Map<String, UriResolver> currentContextPackageUriResolvers =
      <String, UriResolver>{};

  /**
   * Map from context to packages object.
   */
  final Map<String, Packages> currentContextPackagespecs = <String, Packages>{};

  TestContextManager(MemoryResourceProvider resourceProvider,
      ResolverProvider packageResolverProvider,
      OptimizingPubPackageMapProvider packageMapProvider)
      : super(resourceProvider, packageResolverProvider, packageMapProvider,
          InstrumentationService.NULL_SERVICE);

  /**
   * Iterable of the paths to contexts that currently exist.
   */
  Iterable<String> get currentContextPaths => currentContextTimestamps.keys;

  @override
  AnalysisContext addContext(
      Folder folder, UriResolver packageUriResolver, Packages packages) {
    String path = folder.path;
    expect(currentContextPaths, isNot(contains(path)));
    currentContextTimestamps[path] = now;
    currentContextFilePaths[path] = <String, int>{};
    currentContextSources[path] = new HashSet<Source>();
    currentContextPackageUriResolvers[path] = packageUriResolver;
    currentContextPackagespecs[path] = packages;
    currentContext = AnalysisEngine.instance.createAnalysisContext();
    List<UriResolver> resolvers = [new FileUriResolver()];
    if (packageUriResolver != null) {
      resolvers.add(packageUriResolver);
    }
    currentContext.sourceFactory = new SourceFactory(resolvers, packages);
    return currentContext;
  }

  @override
  void applyChangesToContext(Folder contextFolder, ChangeSet changeSet) {
    Map<String, int> filePaths = currentContextFilePaths[contextFolder.path];
    Set<Source> sources = currentContextSources[contextFolder.path];

    for (Source source in changeSet.addedSources) {
      expect(filePaths, isNot(contains(source.fullName)));
      filePaths[source.fullName] = now;
      sources.add(source);
    }
    for (Source source in changeSet.removedSources) {
      expect(filePaths, contains(source.fullName));
      filePaths.remove(source.fullName);
      sources.remove(source);
    }
    for (Source source in changeSet.changedSources) {
      expect(filePaths, contains(source.fullName));
      filePaths[source.fullName] = now;
    }

    currentContext.applyChanges(changeSet);
  }

  void assertContextFiles(String contextPath, List<String> expectedFiles) {
    var actualFiles = currentContextFilePaths[contextPath].keys;
    expect(actualFiles, unorderedEquals(expectedFiles));
  }

  void assertContextPaths(List<String> expected) {
    expect(currentContextPaths, unorderedEquals(expected));
  }

  @override
  void removeContext(Folder folder) {
    String path = folder.path;
    expect(currentContextPaths, contains(path));
    currentContextTimestamps.remove(path);
    currentContextFilePaths.remove(path);
    currentContextSources.remove(path);
    currentContextPackageUriResolvers.remove(path);
  }

  @override
  bool shouldFileBeAnalyzed(File file) {
    if (!(AnalysisEngine.isDartFileName(file.path) ||
        AnalysisEngine.isHtmlFileName(file.path))) {
      return false;
    }
    // Emacs creates dummy links to track the fact that a file is open for
    // editing and has unsaved changes (e.g. having unsaved changes to
    // 'foo.dart' causes a link '.#foo.dart' to be created, which points to the
    // non-existent file 'username@hostname.pid'.  To avoid these dummy links
    // causing the analyzer to thrash, just ignore links to non-existent files.
    return file.exists;
  }

  @override
  void updateContextPackageUriResolver(
      Folder contextFolder, UriResolver packageUriResolver, Packages packages) {
    currentContextPackageUriResolvers[contextFolder.path] = packageUriResolver;
    currentContextPackagespecs[contextFolder.path] = packages;
  }
}

/**
 * A [Source] that knows it's [fullName].
 */
class TestSource implements Source {
  TestSource();

  @override
  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
}

class TestUriResolver extends UriResolver {
  Map<Uri, Source> uriMap;

  TestUriResolver(this.uriMap);

  @override
  Source resolveAbsolute(Uri uri) {
    return uriMap[uri];
  }
}