Add watch and modify/delete support to MemoryFile.

pkg/analysis_server/test/resource_test.dart

Index: pkg/analysis_server/test/resource_test.dart
diff --git a/pkg/analysis_server/test/resource_test.dart b/pkg/analysis_server/test/resource_test.dart
index 2f4c996b3fa67ac748b210b7709dae95b8b947fe..8bc7cc4efabe9659656655205c620754ee5620f2 100644
--- a/pkg/analysis_server/test/resource_test.dart
+++ b/pkg/analysis_server/test/resource_test.dart
@@ -7,6 +7,8 @@ library test.resource;
 import 'dart:async';
 import 'dart:io' as io;
 
+import 'mocks.dart';
+
 import 'package:analysis_server/src/resource.dart';
 import 'package:analyzer/src/generated/engine.dart' show TimestampedData;
 import 'package:analyzer/src/generated/source_io.dart';
@@ -32,6 +34,85 @@ main() {
           'MemoryResourceException(path=/my/path; message=my message)');
     });
 
+    group('Watch', () {
+
+      Future delayed(computation()) {
+        return pumpEventQueue().then((_) => computation());
+      }
+
+      watchingFolder(String path, test(List<WatchEvent> changesReceived)) {
+        Folder folder = provider.getResource(path);
+        var changesReceived = <WatchEvent>[];
+        var subscription = folder.changes.listen(changesReceived.add);
+        return test(changesReceived);
+      }
+
+      test('create file', () {
+        var rootPath = '/my/path';
+        provider.newFolder(rootPath);
+        watchingFolder(rootPath, (changesReceived) {
+          expect(changesReceived, hasLength(0));
+          var path = posix.join(rootPath, 'foo');
+          provider.newFile(path, 'contents');
+          return delayed(() {
+            expect(changesReceived, hasLength(1));
+            expect(changesReceived[0].type, equals(ChangeType.ADD));
+            expect(changesReceived[0].path, equals(path));
+          });
+        });
+      });
+
+      test('modify file', () {
+        var rootPath = '/my/path';
+        provider.newFolder(rootPath);
+        var path = join(rootPath, 'foo');
+        provider.newFile(path, 'contents 1');
+        return watchingFolder(rootPath, (changesReceived) {
+          expect(changesReceived, hasLength(0));
+          provider.modifyFile(path, 'contents 2');
+          return delayed(() {
+            expect(changesReceived, hasLength(1));
+            expect(changesReceived[0].type, equals(ChangeType.MODIFY));
+            expect(changesReceived[0].path, equals(path));
+          });
+        });
+      });
+
+      test('modify file in subdir', () {
+        var rootPath = '/my/path';
+        provider.newFolder(rootPath);
+        var subdirPath = join(rootPath, 'foo');
+        provider.newFolder(subdirPath);
+        var path = join(rootPath, 'bar');
+        provider.newFile(path,  'contents 1');
+        return watchingFolder(rootPath, (changesReceived) {
+          expect(changesReceived, hasLength(0));
+          provider.modifyFile(path, 'contents 2');
+          return delayed(() {
+            expect(changesReceived, hasLength(1));
+            expect(changesReceived[0].type, equals(ChangeType.MODIFY));
+            expect(changesReceived[0].path, equals(path));
+          });
+        });
+      });
+
+      test('delete file', () {
+        var rootPath = '/my/path';
+        provider.newFolder(rootPath);
+        var path = join(rootPath, 'foo');
+        provider.newFile(path, 'contents 1');
+        return watchingFolder(rootPath, (changesReceived) {
+          expect(changesReceived, hasLength(0));
+          provider.deleteFile(path);
+          return delayed(() {
+            expect(changesReceived, hasLength(1));
+            expect(changesReceived[0].type, equals(ChangeType.REMOVE));
+            expect(changesReceived[0].path, equals(path));
+          });
+        });
+      });
+    });
+
     group('newFolder', () {
       test('empty path', () {
         expect(
@@ -70,6 +151,65 @@ main() {
       });
     });
 
+    group('modifyFile', () {
+      test('nonexistent', () {
+        var path = '/my/file';
+        expect(() { provider.modifyFile(path, 'contents'); },
+            throwsA(new isInstanceOf<ArgumentError>()));
+        var file = provider.getResource(path);
+        expect(file, isNotNull);
+        expect(file.exists, isFalse);
+      });
+
+      test('is folder', () {
+        var path = '/my/file';
+        provider.newFolder(path);
+        expect(() { provider.modifyFile(path, 'contents'); },
+            throwsA(new isInstanceOf<ArgumentError>()));
+        expect(provider.getResource(path), new isInstanceOf<Folder>());
+      });
+
+      test('successful', () {
+        var path = '/my/file';
+        provider.newFile(path, 'contents 1');
+        var file = provider.getResource(path);
+        expect(file, new isInstanceOf<File>());
+        var source = file.createSource(UriKind.FILE_URI);
+        expect(source.contents.data, equals('contents 1'));
+        provider.modifyFile(path, 'contents 2');
+        expect(source.contents.data, equals('contents 2'));
+      });
+    });
+
+    group('deleteFile', () {
+      test('nonexistent', () {
+        var path = '/my/file';
+        expect(() { provider.deleteFile(path); },
+            throwsA(new isInstanceOf<ArgumentError>()));
+        var file = provider.getResource(path);
+        expect(file, isNotNull);
+        expect(file.exists, isFalse);
+      });
+
+      test('is folder', () {
+        var path = '/my/file';
+        provider.newFolder(path);
+        expect(() { provider.deleteFile(path); },
+            throwsA(new isInstanceOf<ArgumentError>()));
+        expect(provider.getResource(path), new isInstanceOf<Folder>());
+      });
+
+      test('successful', () {
+        var path = '/my/file';
+        provider.newFile(path, 'contents');
+        var file = provider.getResource(path);
+        expect(file, new isInstanceOf<File>());
+        expect(file.exists, isTrue);
+        provider.deleteFile(path);
+        expect(file.exists, isFalse);
+      });
+    });
+
     group('File', () {
       group('==', () {
         test('false', () {