Library tour example tests for dart:io

Contributes to dart-lang#407 and dart-lang#416.

Continuation of dart-lang#443

examples/lib/library_tour/io/http_server.dart

@@ -0,0 +1,31 @@
+// #docplaster
+import 'dart:async';
+import 'dart:io';
+
+int stopAfter = 10;
+// #docregion
+Future main() async {
+  var requests = await HttpServer.bind('localhost', 8888);
+  // #enddocregion
+  requests = requests.take(stopAfter);
+  // #docregion
+  await for (var request in requests) {
+    processRequest(request);
+  }
+}
+
+void processRequest(HttpRequest request) {
+  print('Got request for ${request.uri.path}');
+  final response = request.response;
+  if (request.uri.path == '/dart') {
+    response
+      ..headers.contentType = new ContentType(
+        'text',
+        'plain',
+      )
+      ..write('Hello from the server');
+  } else {
+    response.statusCode = HttpStatus.NOT_FOUND;
+  }
+  response.close();
+}

examples/test/library_tour/html_test.dart

@@ -184,7 +184,7 @@ void main() {
     // #enddocregion initWebSocket
 
     final t = wsStream.stream.timeout(
-      new Duration(seconds: 1),
+      new Duration(seconds: 5),
       onTimeout: (s) => s.add('Timeout!'),
     );
 
@@ -195,18 +195,4 @@ void main() {
       await wsStream.close();
     }
   });
-
-  group('xxxx', () {
-    test('xxxxx', () {
-      // #docregion xxxx
-      11111;
-      // #enddocregion xxxx
-    });
-
-    test('xxxxx', () {
-      // #docregion xxxx
-      11111;
-      // #enddocregion xxxx
-    });
-  });
 }

examples/test/library_tour/io_test.dart

@@ -0,0 +1,179 @@
+// ignore_for_file: non_constant_identifier_names
+// #docplaster
+// #docregion read-from-stream
+import 'dart:async';
+// #docregion import
+import 'dart:io';
+// #enddocregion import
+import 'dart:convert';
+
+// #enddocregion read-from-stream
+import 'package:test/test.dart';
+import '../../lib/library_tour/io/http_server.dart'
+    as http_server;
+import '../util/print_matcher.dart' as m;
+
+void main() {
+  test('readAsString, readAsLines', () async {
+    // #docregion readAsString
+    Future main() async {
+      var config = new File('test_data/config.txt');
+      var contents;
+
+      // Put the whole file in a single string.
+      contents = await config.readAsString();
+      print('The file is ${contents.length} characters long.');
+
+      // Put each line of the file into its own string.
+      contents = await config.readAsLines();
+      print('The file is ${contents.length} lines long.');
+    }
+    // #enddocregion readAsString
+
+    expect(
+        main,
+        m.prints([
+          'The file is 58 characters long.',
+          'The file is 4 lines long.'
+        ]));
+  });
+
+  test('readAsBytes', () {
+    // #docregion readAsBytes
+    Future main() async {
+      var config = new File('test_data/config.txt');
+
+      var contents = await config.readAsBytes();
+      print('The file is ${contents.length} bytes long.');
+    }
+    // #enddocregion readAsBytes
+
+    expect(main, m.prints('The file is 58 bytes long.'));
+  });
+
+  test('try-catch', () {
+    // #docregion try-catch
+    Future main() async {
+      var config = new File('does-not-exist.txt');
+      try {
+        var contents = await config.readAsString();
+        print(contents);
+      } catch (e) {
+        print(e);
+      }
+    }
+
+    // #enddocregion try-catch
+    expect(main, prints(startsWith('FileSystemException')));
+  });
+
+  test('read-from-stream', () {
+    expect(
+        main_test_read_from_stream,
+        prints(allOf([
+          contains(
+              new RegExp(r'Got \d+ characters from stream')),
+          contains('file is now closed'),
+        ])));
+  });
+
+  test('write-file', () async {
+    // #docregion write-file
+    var logFile = new File('test_data/log.txt');
+    var sink = logFile.openWrite();
+    sink.write('FILE ACCESSED ${new DateTime.now()}\n');
+    await sink.flush();
+    await sink.close();
+    // #enddocregion write-file
+    try {
+      expect(logFile.existsSync(), isTrue);
+      expect(logFile.readAsStringSync(),
+          startsWith('FILE ACCESSED'));
+    } finally {
+      logFile?.delete();
+    }
+  });
+
+  test('list-dir', () {
+    // #docregion list-dir
+    Future main() async {
+      var dir = new Directory('test_data');
+
+      try {
+        var dirList = dir.list();
+        await for (FileSystemEntity f in dirList) {
+          if (f is File) {
+            print('Found file ${f.path}');
+          } else if (f is Directory) {
+            print('Found dir ${f.path}');
+          }
+        }
+      } catch (e) {
+        print(e.toString());
+      }
+    }
+
+    // #enddocregion list-dir
+    expect(main, prints(contains('Found file')));
+  });
+
+  test('client-server', () async {
+    // #docregion client
+    Future main() async {
+      var url = Uri.parse('http://localhost:8888/dart');
+      var httpClient = new HttpClient();
+      var request = await httpClient.getUrl(url);
+      var response = await request.close();
+      var data = await response.transform(UTF8.decoder).toList();
+      print('Response ${response.statusCode}: $data');
+      httpClient.close();
+    }
+    // #enddocregion client
+
+    http_server.stopAfter = 1;
+    final clientAndServer = () => Future.wait([
+          http_server.main(),
+          main(),
+        ]);
+    expect(
+        clientAndServer,
+        m.prints([
+          'Got request for /dart',
+          'Response 200: [Hello from the server]'
+        ]));
+  });
+}
+
+// The following function is defined here so that it is left
+// aligned with the import statements, which are also
+// included in the excerpt.
+
+// #docregion read-from-stream
+Future main_test_read_from_stream() async {
+  var config = new File('test_data/config.txt');
+  Stream<List<int>> inputStream = config.openRead();
+
+  var lines = inputStream
+      .transform(UTF8.decoder)
+      .transform(new LineSplitter());
+  try {
+    await for (var line in lines) {
+      print('Got ${line.length} characters from stream');
+    }
+    print('file is now closed');
+  } catch (e) {
+    print(e);
+  }
+}
+// #enddocregion read-from-stream
+
+/// No tests below this point. Excerpts only illustrate declarations.
+void miscDeclAnalyzedButNotTested() {
+  {
+    var logFile = new File('test_data/log.txt');
+    // #docregion append
+    var sink = logFile.openWrite(mode: FileMode.APPEND);
+    // #enddocregion append
+    sink.close();
+  }
+}

examples/test_data/config.txt

@@ -0,0 +1,4 @@
+Llamas
+Dromedaries
+Oases in the Desert
+And other oddities

scripts/dartfmt.sh

@@ -42,7 +42,9 @@ $DARTFMT -l 65 \
   examples/lib/language_tour/exceptions.dart \
   examples/test/library_tour/core_test.dart \
   examples/lib/library_tour/async/future.dart \
-  examples/lib/library_tour/async/stream.dart
+  examples/lib/library_tour/async/stream.dart \
+  examples/test/library_tour/io_test.dart
+
 
 # If any files were changed, then exit 1:
 REFORMATTED_FILES=$(git status --short)