Better toString() implementations (flutter#68)

Fixes flutter#67

Author: tvolkert

lib/src/backends/local/local_directory.dart

@@ -8,4 +8,7 @@ class _LocalDirectory
     extends _LocalFileSystemEntity<_LocalDirectory, io.Directory>
     with ForwardingDirectory {
   _LocalDirectory(FileSystem fs, io.Directory delegate) : super(fs, delegate);
+
+  @override
+  String toString() => "LocalDirectory: '$path'";
 }

lib/src/backends/local/local_file.dart

@@ -7,4 +7,7 @@ part of file.src.backends.local;
 class _LocalFile extends _LocalFileSystemEntity<File, io.File>
     with ForwardingFile {
   _LocalFile(FileSystem fs, io.File delegate) : super(fs, delegate);
+
+  @override
+  String toString() => "LocalFile: '$path'";
 }

lib/src/backends/local/local_link.dart

@@ -7,4 +7,7 @@ part of file.src.backends.local;
 class _LocalLink extends _LocalFileSystemEntity<Link, io.Link>
     with ForwardingLink {
   _LocalLink(FileSystem fs, io.Link delegate) : super(fs, delegate);
+
+  @override
+  String toString() => "LocalLink: '$path'";
 }

lib/src/backends/memory/memory_directory.dart

@@ -137,6 +137,9 @@ class _MemoryDirectory extends _MemoryFileSystemEntity implements Directory {
 
   @override
   Directory _clone(String path) => new _MemoryDirectory(fileSystem, path);
+
+  @override
+  String toString() => "MemoryDirectory: '$path'";
 }
 
 class _PendingListTask {

lib/src/backends/memory/memory_file.dart

@@ -240,6 +240,9 @@ class _MemoryFile extends _MemoryFileSystemEntity implements File {
       node.content.clear();
     }
   }
+
+  @override
+  String toString() => "MemoryFile: '$path'";
 }
 
 /// Implementation of an [io.IOSink] that's backed by a [_FileNode].

lib/src/backends/memory/memory_link.dart

@@ -92,4 +92,7 @@ class _MemoryLink extends _MemoryFileSystemEntity implements Link {
 
   @override
   Link _clone(String path) => new _MemoryLink(fileSystem, path);
+
+  @override
+  String toString() => "MemoryLink: '$path'";
 }

test/local_test.dart

@@ -67,5 +67,19 @@ void main() {
         'Link > rename > throwsIfDestinationExistsAsFile',
       ],
     );
+
+    group('toString', () {
+      test('File', () {
+        expect(fs.file('/foo').toString(), "LocalFile: '/foo'");
+      });
+
+      test('Directory', () {
+        expect(fs.directory('/foo').toString(), "LocalDirectory: '/foo'");
+      });
+
+      test('Link', () {
+        expect(fs.link('/foo').toString(), "LocalLink: '/foo'");
+      });
+    });
   });
 }

test/memory_test.dart

@@ -9,11 +9,31 @@ import 'common_tests.dart';
 
 void main() {
   group('MemoryFileSystem', () {
+    MemoryFileSystem fs;
+
+    setUp(() {
+      fs = new MemoryFileSystem();
+    });
+
     runCommonTests(
-      () => new MemoryFileSystem(),
+      () => fs,
       skip: <String>[
         'File > open', // Not yet implemented
       ],
     );
+
+    group('toString', () {
+      test('File', () {
+        expect(fs.file('/foo').toString(), "MemoryFile: '/foo'");
+      });
+
+      test('Directory', () {
+        expect(fs.directory('/foo').toString(), "MemoryDirectory: '/foo'");
+      });
+
+      test('Link', () {
+        expect(fs.link('/foo').toString(), "MemoryLink: '/foo'");
+      });
+    });
   });
 }