diff --git a/example/example.dart b/example/example.dart
index e940925..6d6beaf 100644
--- a/example/example.dart
+++ b/example/example.dart
@@ -5,7 +5,7 @@
 import 'package:shelf/shelf.dart' as shelf;
 import 'package:shelf/shelf_io.dart' as io;
 
-main() async {
+void main() async {
   var handler = const shelf.Pipeline()
       .addMiddleware(shelf.logRequests())
       .addHandler(_echoRequest);
diff --git a/lib/shelf_io.dart b/lib/shelf_io.dart
index aa0c130..d41b8dc 100644
--- a/lib/shelf_io.dart
+++ b/lib/shelf_io.dart
@@ -41,7 +41,7 @@
 Future<HttpServer> serve(Handler handler, address, int port,
     {SecurityContext securityContext, int backlog, bool shared = false}) async {
   backlog ??= 0;
-  HttpServer server = await (securityContext == null
+  var server = await (securityContext == null
       ? HttpServer.bind(address, port, backlog: backlog, shared: shared)
       : HttpServer.bindSecure(address, port, securityContext,
           backlog: backlog, shared: shared));
@@ -121,10 +121,10 @@
   }
 
   var message = StringBuffer()
-    ..writeln("Got a response for hijacked request "
-        "${shelfRequest.method} ${shelfRequest.requestedUri}:")
+    ..writeln('Got a response for hijacked request '
+        '${shelfRequest.method} ${shelfRequest.requestedUri}:')
     ..writeln(response.statusCode);
-  response.headers.forEach((key, value) => message.writeln("$key: $value"));
+  response.headers.forEach((key, value) => message.writeln('$key: $value'));
   throw Exception(message.toString().trim());
 }
 
@@ -140,7 +140,7 @@
   // Remove the Transfer-Encoding header per the adapter requirements.
   headers.remove(HttpHeaders.transferEncodingHeader);
 
-  void onHijack(void callback(StreamChannel<List<int>> channel)) {
+  void onHijack(void Function(StreamChannel<List<int>>) callback) {
     request.response
         .detachSocket(writeHeaders: false)
         .then((socket) => callback(StreamChannel(socket, socket)));
@@ -155,9 +155,9 @@
 }
 
 Future _writeResponse(Response response, HttpResponse httpResponse) {
-  if (response.context.containsKey("shelf.io.buffer_output")) {
+  if (response.context.containsKey('shelf.io.buffer_output')) {
     httpResponse.bufferOutput =
-        response.context["shelf.io.buffer_output"] as bool;
+        response.context['shelf.io.buffer_output'] as bool;
   }
 
   httpResponse.statusCode = response.statusCode;
@@ -210,9 +210,9 @@
 Response _logError(Request request, String message, [StackTrace stackTrace]) {
   // Add information about the request itself.
   var buffer = StringBuffer();
-  buffer.write("${request.method} ${request.requestedUri.path}");
+  buffer.write('${request.method} ${request.requestedUri.path}');
   if (request.requestedUri.query.isNotEmpty) {
-    buffer.write("?${request.requestedUri.query}");
+    buffer.write('?${request.requestedUri.query}');
   }
   buffer.writeln();
   buffer.write(message);
diff --git a/lib/src/body.dart b/lib/src/body.dart
index 1ad6f3f..a4660fb 100644
--- a/lib/src/body.dart
+++ b/lib/src/body.dart
@@ -84,7 +84,7 @@
   Stream<List<int>> read() {
     if (_stream == null) {
       throw StateError("The 'read' method can only be called once on a "
-          "shelf.Request/shelf.Response object.");
+          'shelf.Request/shelf.Response object.');
     }
     var stream = _stream;
     _stream = null;
diff --git a/lib/src/cascade.dart b/lib/src/cascade.dart
index 459e780..de991b3 100644
--- a/lib/src/cascade.dart
+++ b/lib/src/cascade.dart
@@ -39,13 +39,13 @@
   /// considered unacceptable. If [shouldCascade] is passed, responses for which
   /// it returns `true` are considered unacceptable. [statusCodes] and
   /// [shouldCascade] may not both be passed.
-  Cascade({Iterable<int> statusCodes, bool shouldCascade(Response response)})
+  Cascade({Iterable<int> statusCodes, bool Function(Response) shouldCascade})
       : _shouldCascade = _computeShouldCascade(statusCodes, shouldCascade),
         _parent = null,
         _handler = null {
     if (statusCodes != null && shouldCascade != null) {
-      throw ArgumentError("statusCodes and shouldCascade may not both be "
-          "passed.");
+      throw ArgumentError('statusCodes and shouldCascade may not both be '
+          'passed.');
     }
   }
 
@@ -65,7 +65,7 @@
   Handler get handler {
     if (_handler == null) {
       throw StateError("Can't get a handler for a cascade with no inner "
-          "handlers.");
+          'handlers.');
     }
 
     return (request) {
@@ -81,9 +81,9 @@
 /// Computes the [Cascade._shouldCascade] function based on the user's
 /// parameters.
 _ShouldCascade _computeShouldCascade(
-    Iterable<int> statusCodes, bool shouldCascade(Response response)) {
+    Iterable<int> statusCodes, bool Function(Response) shouldCascade) {
   if (shouldCascade != null) return shouldCascade;
-  if (statusCodes == null) statusCodes = [404, 405];
+  statusCodes ??= [404, 405];
   statusCodes = statusCodes.toSet();
   return (response) => statusCodes.contains(response.statusCode);
 }
diff --git a/lib/src/hijack_exception.dart b/lib/src/hijack_exception.dart
index d7e4cd1..4a3d84e 100644
--- a/lib/src/hijack_exception.dart
+++ b/lib/src/hijack_exception.dart
@@ -12,8 +12,9 @@
 class HijackException implements Exception {
   const HijackException();
 
+  @override
   String toString() =>
       "A shelf request's underlying data stream was hijacked.\n"
-      "This exception is used for control flow and should only be handled by a "
-      "Shelf adapter.";
+      'This exception is used for control flow and should only be handled by a '
+      'Shelf adapter.';
 }
diff --git a/lib/src/io_server.dart b/lib/src/io_server.dart
index 447f307..19c5e37 100644
--- a/lib/src/io_server.dart
+++ b/lib/src/io_server.dart
@@ -18,21 +18,22 @@
   /// Whether [mount] has been called.
   bool _mounted = false;
 
+  @override
   Uri get url {
     if (server.address.isLoopback) {
-      return Uri(scheme: "http", host: "localhost", port: server.port);
+      return Uri(scheme: 'http', host: 'localhost', port: server.port);
     }
 
     // IPv6 addresses in URLs need to be enclosed in square brackets to avoid
     // URL ambiguity with the ":" in the address.
     if (server.address.type == InternetAddressType.IPv6) {
       return Uri(
-          scheme: "http",
-          host: "[${server.address.address}]",
+          scheme: 'http',
+          host: '[${server.address.address}]',
           port: server.port);
     }
 
-    return Uri(scheme: "http", host: server.address.address, port: server.port);
+    return Uri(scheme: 'http', host: server.address.address, port: server.port);
   }
 
   /// Calls [HttpServer.bind] and wraps the result in an [IOServer].
@@ -44,6 +45,7 @@
 
   IOServer(this.server);
 
+  @override
   void mount(Handler handler) {
     if (_mounted) {
       throw StateError("Can't mount two handlers for the same server.");
@@ -53,5 +55,6 @@
     serveRequests(server, handler);
   }
 
+  @override
   Future close() => server.close();
 }
diff --git a/lib/src/message.dart b/lib/src/message.dart
index cd19f03..1796fa8 100644
--- a/lib/src/message.dart
+++ b/lib/src/message.dart
@@ -17,7 +17,7 @@
 /// The default set of headers for a message created with no body and no
 /// explicit headers.
 final _defaultHeaders =
-    ShelfUnmodifiableMap<String>({"content-length": "0"}, ignoreKeyCase: true);
+    ShelfUnmodifiableMap<String>({'content-length': '0'}, ignoreKeyCase: true);
 
 /// Represents logic shared between [Request] and [Response].
 abstract class Message {
@@ -136,8 +136,7 @@
   ///
   /// This calls [read] internally, which can only be called once.
   Future<String> readAsString([Encoding encoding]) {
-    if (encoding == null) encoding = this.encoding;
-    if (encoding == null) encoding = utf8;
+    encoding ??= this.encoding ?? utf8;
     return encoding.decodeStream(read());
   }
 
diff --git a/lib/src/middleware.dart b/lib/src/middleware.dart
index 05b9b47..d972a67 100644
--- a/lib/src/middleware.dart
+++ b/lib/src/middleware.dart
@@ -47,12 +47,11 @@
 /// does it receive [HijackException]s. It can either return a new response or
 /// throw an error.
 Middleware createMiddleware(
-    {FutureOr<Response> requestHandler(Request request),
-    FutureOr<Response> responseHandler(Response response),
-    FutureOr<Response> errorHandler(error, StackTrace stackTrace)}) {
-  if (requestHandler == null) requestHandler = (request) => null;
-
-  if (responseHandler == null) responseHandler = (response) => response;
+    {FutureOr<Response> Function(Request) requestHandler,
+    FutureOr<Response> Function(Response) responseHandler,
+    FutureOr<Response> Function(dynamic error, StackTrace) errorHandler}) {
+  requestHandler ??= (request) => null;
+  responseHandler ??= (response) => response;
 
   void Function(Object, StackTrace) onError;
   if (errorHandler != null) {
diff --git a/lib/src/middleware/logger.dart b/lib/src/middleware/logger.dart
index 0d11ca1..444ef08 100644
--- a/lib/src/middleware/logger.dart
+++ b/lib/src/middleware/logger.dart
@@ -19,9 +19,9 @@
 /// The `isError` parameter indicates whether the message is caused by an error.
 ///
 /// If [logger] is not passed, the message is just passed to [print].
-Middleware logRequests({void logger(String msg, bool isError)}) =>
+Middleware logRequests({void Function(String message, bool isError) logger}) =>
     (innerHandler) {
-      if (logger == null) logger = _defaultLogger;
+      logger ??= _defaultLogger;
 
       return (request) {
         var startTime = DateTime.now();
diff --git a/lib/src/request.dart b/lib/src/request.dart
index c5ae87f..9c6d1cb 100644
--- a/lib/src/request.dart
+++ b/lib/src/request.dart
@@ -134,7 +134,7 @@
       body,
       Encoding encoding,
       Map<String, Object> context,
-      void onHijack(void hijack(StreamChannel<List<int>> channel))})
+      void Function(void Function(StreamChannel<List<int>>)) onHijack})
       : this._(method, requestedUri,
             protocolVersion: protocolVersion,
             headers: headers,
@@ -160,12 +160,11 @@
       Encoding encoding,
       Map<String, Object> context,
       _OnHijack onHijack})
-      : this.requestedUri = requestedUri,
-        this.protocolVersion =
-            protocolVersion == null ? '1.1' : protocolVersion,
-        this.url = _computeUrl(requestedUri, handlerPath, url),
-        this.handlerPath = _computeHandlerPath(requestedUri, handlerPath, url),
-        this._onHijack = onHijack,
+      : requestedUri = requestedUri,
+        protocolVersion = protocolVersion ?? '1.1',
+        url = _computeUrl(requestedUri, handlerPath, url),
+        handlerPath = _computeHandlerPath(requestedUri, handlerPath, url),
+        _onHijack = onHijack,
         super(body, encoding: encoding, headers: headers, context: context) {
     if (method.isEmpty) {
       throw ArgumentError.value(method, 'method', 'cannot be empty.');
@@ -214,6 +213,7 @@
   ///     request = request.change(path: "dir");
   ///     print(request.handlerPath); // => /static/dir/
   ///     print(request.url);        // => file.html
+  @override
   Request change(
       {Map<String, String> headers,
       Map<String, Object> context,
@@ -222,13 +222,13 @@
     headers = updateMap(this.headers, headers);
     context = updateMap(this.context, context);
 
-    if (body == null) body = getBody(this);
+    body ??= getBody(this);
 
     var handlerPath = this.handlerPath;
     if (path != null) handlerPath += path;
 
-    return Request._(this.method, this.requestedUri,
-        protocolVersion: this.protocolVersion,
+    return Request._(method, requestedUri,
+        protocolVersion: protocolVersion,
         headers: headers,
         handlerPath: handlerPath,
         body: body,
@@ -247,7 +247,7 @@
   /// hijacking, such as the `dart:io` adapter. In addition, a given request may
   /// only be hijacked once. [canHijack] can be used to detect whether this
   /// request can be hijacked.
-  void hijack(void callback(StreamChannel<List<int>> channel)) {
+  void hijack(void Function(StreamChannel<List<int>>) callback) {
     if (_onHijack == null) {
       throw StateError("This request can't be hijacked.");
     }
@@ -272,8 +272,8 @@
   /// Calls [this].
   ///
   /// Throws a [StateError] if [this] has already been called.
-  void run(void callback(StreamChannel<List<int>> channel)) {
-    if (called) throw StateError("This request has already been hijacked.");
+  void run(void Function(StreamChannel<List<int>>) callback) {
+    if (called) throw StateError('This request has already been hijacked.');
     called = true;
     newFuture(() => _callback(callback));
   }
@@ -286,8 +286,8 @@
 Uri _computeUrl(Uri requestedUri, String handlerPath, Uri url) {
   if (handlerPath != null &&
       handlerPath != requestedUri.path &&
-      !handlerPath.endsWith("/")) {
-    handlerPath += "/";
+      !handlerPath.endsWith('/')) {
+    handlerPath += '/';
   }
 
   if (url != null) {
@@ -336,8 +336,8 @@
 String _computeHandlerPath(Uri requestedUri, String handlerPath, Uri url) {
   if (handlerPath != null &&
       handlerPath != requestedUri.path &&
-      !handlerPath.endsWith("/")) {
-    handlerPath += "/";
+      !handlerPath.endsWith('/')) {
+    handlerPath += '/';
   }
 
   if (handlerPath != null) {
diff --git a/lib/src/response.dart b/lib/src/response.dart
index b7275b0..ada9744 100644
--- a/lib/src/response.dart
+++ b/lib/src/response.dart
@@ -198,7 +198,7 @@
       Map<String, Object> context})
       : this(403,
             headers: body == null ? _adjustErrorHeaders(headers) : headers,
-            body: body == null ? 'Forbidden' : body,
+            body: body ?? 'Forbidden',
             context: context,
             encoding: encoding);
 
@@ -227,7 +227,7 @@
       Map<String, Object> context})
       : this(404,
             headers: body == null ? _adjustErrorHeaders(headers) : headers,
-            body: body == null ? 'Not Found' : body,
+            body: body ?? 'Not Found',
             context: context,
             encoding: encoding);
 
@@ -257,7 +257,7 @@
       Map<String, Object> context})
       : this(500,
             headers: body == null ? _adjustErrorHeaders(headers) : headers,
-            body: body == null ? 'Internal Server Error' : body,
+            body: body ?? 'Internal Server Error',
             context: context,
             encoding: encoding);
 
@@ -286,7 +286,7 @@
       Map<String, Object> context})
       : super(body, encoding: encoding, headers: headers, context: context) {
     if (statusCode < 100) {
-      throw ArgumentError("Invalid status code: $statusCode.");
+      throw ArgumentError('Invalid status code: $statusCode.');
     }
   }
 
@@ -305,15 +305,15 @@
   ///
   /// [body] is the request body. It may be either a [String], a [List<int>], a
   /// [Stream<List<int>>], or `null` to indicate no body.
+  @override
   Response change(
       {Map<String, String> headers, Map<String, Object> context, body}) {
     headers = updateMap(this.headers, headers);
     context = updateMap(this.context, context);
 
-    if (body == null) body = getBody(this);
+    body ??= getBody(this);
 
-    return Response(this.statusCode,
-        body: body, headers: headers, context: context);
+    return Response(statusCode, body: body, headers: headers, context: context);
   }
 }
 
diff --git a/lib/src/server_handler.dart b/lib/src/server_handler.dart
index c6b6afd..6aa999d 100644
--- a/lib/src/server_handler.dart
+++ b/lib/src/server_handler.dart
@@ -38,12 +38,13 @@
   ///
   /// If [onClose] is passed, it's called when [server] is closed. It may return
   /// a [Future] or `null`; its return value is returned by [Server.close].
-  ServerHandler(Uri url, {onClose()}) : _server = _HandlerServer(url, onClose);
+  ServerHandler(Uri url, {void Function() onClose})
+      : _server = _HandlerServer(url, onClose);
 
   /// Pipes requests to [server]'s handler.
   FutureOr<Response> _onRequest(Request request) {
     if (_server._closeMemo.hasRun) {
-      throw StateError("Request received after the server was closed.");
+      throw StateError('Request received after the server was closed.');
     }
 
     if (_server._handler != null) return _server._handler(request);
@@ -56,6 +57,7 @@
 
 /// The [Server] returned by [ServerHandler].
 class _HandlerServer implements Server {
+  @override
   final Uri url;
 
   /// The callback to call when [close] is called, or `null`.
@@ -72,6 +74,7 @@
 
   _HandlerServer(this.url, this._onClose);
 
+  @override
   void mount(Handler handler) {
     if (_handler != null) {
       throw StateError("Can't mount two handlers for the same server.");
@@ -81,6 +84,7 @@
     _onMountedCompleter.complete();
   }
 
+  @override
   Future close() => _closeMemo.runOnce(() {
         return _onClose == null ? null : _onClose();
       });
diff --git a/lib/src/shelf_unmodifiable_map.dart b/lib/src/shelf_unmodifiable_map.dart
index e23df7b..794cb00 100644
--- a/lib/src/shelf_unmodifiable_map.dart
+++ b/lib/src/shelf_unmodifiable_map.dart
@@ -53,13 +53,17 @@
 /// A const implementation of an empty [ShelfUnmodifiableMap].
 class _EmptyShelfUnmodifiableMap<V> extends MapView<String, V>
     implements ShelfUnmodifiableMap<V> {
+  @override
   bool get _ignoreKeyCase => true;
   const _EmptyShelfUnmodifiableMap() : super(const <String, Null>{});
 
   // Override modifier methods that care about the type of key they use so that
   // when V is Null, they throw UnsupportedErrors instead of type errors.
+  @override
   void operator []=(String key, Object value) => super[key] = null;
+  @override
   void addAll(Map<String, Object> other) => super.addAll({});
-  V putIfAbsent(String key, Object ifAbsent()) =>
+  @override
+  V putIfAbsent(String key, Object Function() ifAbsent) =>
       super.putIfAbsent(key, () => null);
 }
diff --git a/lib/src/util.dart b/lib/src/util.dart
index b2fc769..5cb0d2e 100644
--- a/lib/src/util.dart
+++ b/lib/src/util.dart
@@ -10,14 +10,16 @@
 
 /// Like [new Future], but avoids around issue 11911 by using [new Future.value]
 /// under the covers.
-Future newFuture(callback()) => Future.value().then((_) => callback());
+Future newFuture(void Function() callback) =>
+    Future.value().then((_) => callback());
 
 /// Run [callback] and capture any errors that would otherwise be top-leveled.
 ///
 /// If [this] is called in a non-root error zone, it will just run [callback]
 /// and return the result. Otherwise, it will capture any errors using
 /// [runZoned] and pass them to [onError].
-catchTopLevelErrors(callback(), void onError(error, StackTrace stackTrace)) {
+void catchTopLevelErrors(void Function() callback,
+    void Function(dynamic error, StackTrace) onError) {
   if (Zone.current.inSameErrorZone(Zone.root)) {
     return runZoned(callback, onError: onError);
   } else {
diff --git a/pubspec.yaml b/pubspec.yaml
index b10625e..5c430c5 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: shelf
-version: 0.7.5
+version: 0.7.6-dev
 description: >-
   A model for web server middleware that encourages composition and easy reuse
 author: Dart Team <misc@dartlang.org>
diff --git a/test/add_chunked_encoding_test.dart b/test/add_chunked_encoding_test.dart
index 2ae1dbf..071739e 100644
--- a/test/add_chunked_encoding_test.dart
+++ b/test/add_chunked_encoding_test.dart
@@ -10,23 +10,23 @@
 void main() {
   test('adds chunked encoding with no transfer-encoding header', () async {
     var response = await _chunkResponse(
-        Response.ok(Stream.fromIterable(["hi".codeUnits])));
+        Response.ok(Stream.fromIterable(['hi'.codeUnits])));
     expect(response.headers, containsPair('transfer-encoding', 'chunked'));
-    expect(response.readAsString(), completion(equals("2\r\nhi\r\n0\r\n\r\n")));
+    expect(response.readAsString(), completion(equals('2\r\nhi\r\n0\r\n\r\n')));
   });
 
   test('adds chunked encoding with transfer-encoding: identity', () async {
     var response = await _chunkResponse(Response.ok(
-        Stream.fromIterable(["hi".codeUnits]),
+        Stream.fromIterable(['hi'.codeUnits]),
         headers: {'transfer-encoding': 'identity'}));
     expect(response.headers, containsPair('transfer-encoding', 'chunked'));
-    expect(response.readAsString(), completion(equals("2\r\nhi\r\n0\r\n\r\n")));
+    expect(response.readAsString(), completion(equals('2\r\nhi\r\n0\r\n\r\n')));
   });
 
   test("doesn't add chunked encoding with content length", () async {
-    var response = await _chunkResponse(Response.ok("hi"));
+    var response = await _chunkResponse(Response.ok('hi'));
     expect(response.headers, isNot(contains('transfer-encoding')));
-    expect(response.readAsString(), completion(equals("hi")));
+    expect(response.readAsString(), completion(equals('hi')));
   });
 
   test("doesn't add chunked encoding with status 1xx", () async {
diff --git a/test/cascade_test.dart b/test/cascade_test.dart
index afa33b4..fa7701c 100644
--- a/test/cascade_test.dart
+++ b/test/cascade_test.dart
@@ -41,7 +41,7 @@
     });
 
     test(
-        "the second response should be returned if it matches and the first "
+        'the second response should be returned if it matches and the first '
         "doesn't", () {
       return Future.sync(() {
         return handler(Request('GET', localhostUri, headers: {'one': 'false'}));
@@ -52,7 +52,7 @@
     });
 
     test(
-        "the third response should be returned if it matches and the first "
+        'the third response should be returned if it matches and the first '
         "two don't", () {
       return Future.sync(() {
         return handler(Request('GET', localhostUri,
@@ -63,7 +63,7 @@
       });
     });
 
-    test("the third response should be returned if no response matches", () {
+    test('the third response should be returned if no response matches', () {
       return Future.sync(() {
         return handler(Request('GET', localhostUri,
             headers: {'one': 'false', 'two': 'false', 'three': 'false'}));
diff --git a/test/io_server_test.dart b/test/io_server_test.dart
index 0ed2a59..26226d4 100644
--- a/test/io_server_test.dart
+++ b/test/io_server_test.dart
@@ -26,19 +26,19 @@
 
   tearDown(() => server.close());
 
-  test("serves HTTP requests with the mounted handler", () async {
+  test('serves HTTP requests with the mounted handler', () async {
     server.mount(syncHandler);
     expect(await http.read(server.url), equals('Hello from /'));
   });
 
-  test("delays HTTP requests until a handler is mounted", () async {
+  test('delays HTTP requests until a handler is mounted', () async {
     expect(http.read(server.url), completion(equals('Hello from /')));
     await Future.delayed(Duration.zero);
 
     server.mount(asyncHandler);
   });
 
-  test("disallows more than one handler from being mounted", () async {
+  test('disallows more than one handler from being mounted', () async {
     server.mount((_) => null);
     expect(() => server.mount((_) => null), throwsStateError);
     expect(() => server.mount((_) => null), throwsStateError);
diff --git a/test/message_change_test.dart b/test/message_change_test.dart
index 17c9d4d..9f93d6d 100644
--- a/test/message_change_test.dart
+++ b/test/message_change_test.dart
@@ -30,8 +30,11 @@
 /// Shared test method used by [Request] and [Response] tests to validate
 /// the behavior of `change` with different `headers` and `context` values.
 void _testChange(
-    Message factory(
-        {body, Map<String, String> headers, Map<String, Object> context})) {
+    Message Function(
+            {dynamic body,
+            Map<String, String> headers,
+            Map<String, Object> context})
+        factory) {
   group('body', () {
     test('with String', () async {
       var request = factory(body: 'Hello, world');
diff --git a/test/message_test.dart b/test/message_test.dart
index 6ee475c..a5de23f 100644
--- a/test/message_test.dart
+++ b/test/message_test.dart
@@ -15,6 +15,7 @@
       Encoding encoding)
       : super(body, headers: headers, context: context, encoding: encoding);
 
+  @override
   Message change(
       {Map<String, String> headers, Map<String, Object> context, body}) {
     throw UnimplementedError();
@@ -74,16 +75,16 @@
     });
   });
 
-  group("readAsString", () {
-    test("supports a null body", () {
+  group('readAsString', () {
+    test('supports a null body', () {
       var request = _createMessage();
-      expect(request.readAsString(), completion(equals("")));
+      expect(request.readAsString(), completion(equals('')));
     });
 
-    test("supports a Stream<List<int>> body", () {
+    test('supports a Stream<List<int>> body', () {
       var controller = StreamController();
       var request = _createMessage(body: controller.stream);
-      expect(request.readAsString(), completion(equals("hello, world")));
+      expect(request.readAsString(), completion(equals('hello, world')));
 
       controller.add(helloBytes);
       return Future(() {
@@ -93,40 +94,40 @@
       });
     });
 
-    test("defaults to UTF-8", () {
+    test('defaults to UTF-8', () {
       var request = _createMessage(
           body: Stream.fromIterable([
         [195, 168]
       ]));
-      expect(request.readAsString(), completion(equals("è")));
+      expect(request.readAsString(), completion(equals('è')));
     });
 
-    test("the content-type header overrides the default", () {
+    test('the content-type header overrides the default', () {
       var request = _createMessage(
           headers: {'content-type': 'text/plain; charset=iso-8859-1'},
           body: Stream.fromIterable([
             [195, 168]
           ]));
-      expect(request.readAsString(), completion(equals("Ã¨")));
+      expect(request.readAsString(), completion(equals('Ã¨')));
     });
 
-    test("an explicit encoding overrides the content-type header", () {
+    test('an explicit encoding overrides the content-type header', () {
       var request = _createMessage(
           headers: {'content-type': 'text/plain; charset=iso-8859-1'},
           body: Stream.fromIterable([
             [195, 168]
           ]));
-      expect(request.readAsString(latin1), completion(equals("Ã¨")));
+      expect(request.readAsString(latin1), completion(equals('Ã¨')));
     });
   });
 
-  group("read", () {
-    test("supports a null body", () {
+  group('read', () {
+    test('supports a null body', () {
       var request = _createMessage();
       expect(request.read().toList(), completion(isEmpty));
     });
 
-    test("supports a Stream<List<int>> body", () {
+    test('supports a Stream<List<int>> body', () {
       var controller = StreamController();
       var request = _createMessage(body: controller.stream);
       expect(request.read().toList(),
@@ -140,12 +141,12 @@
       });
     });
 
-    test("supports a List<int> body", () {
+    test('supports a List<int> body', () {
       var request = _createMessage(body: helloBytes);
       expect(request.read().toList(), completion(equals([helloBytes])));
     });
 
-    test("throws when calling read()/readAsString() multiple times", () {
+    test('throws when calling read()/readAsString() multiple times', () {
       var request;
 
       request = _createMessage();
@@ -166,23 +167,23 @@
     });
   });
 
-  group("content-length", () {
-    test("is 0 with a default body and without a content-length header", () {
+  group('content-length', () {
+    test('is 0 with a default body and without a content-length header', () {
       var request = _createMessage();
       expect(request.contentLength, 0);
     });
 
-    test("comes from a byte body", () {
+    test('comes from a byte body', () {
       var request = _createMessage(body: [1, 2, 3]);
       expect(request.contentLength, 3);
     });
 
-    test("comes from a string body", () {
+    test('comes from a string body', () {
       var request = _createMessage(body: 'foobar');
       expect(request.contentLength, 6);
     });
 
-    test("is set based on byte length for a string body", () {
+    test('is set based on byte length for a string body', () {
       var request = _createMessage(body: 'fööbär');
       expect(request.contentLength, 9);
 
@@ -190,48 +191,48 @@
       expect(request.contentLength, 6);
     });
 
-    test("is null for a stream body", () {
+    test('is null for a stream body', () {
       var request = _createMessage(body: Stream.empty());
       expect(request.contentLength, isNull);
     });
 
-    test("uses the content-length header for a stream body", () {
+    test('uses the content-length header for a stream body', () {
       var request = _createMessage(
           body: Stream.empty(), headers: {'content-length': '42'});
       expect(request.contentLength, 42);
     });
 
-    test("real body length takes precedence over content-length header", () {
+    test('real body length takes precedence over content-length header', () {
       var request =
           _createMessage(body: [1, 2, 3], headers: {'content-length': '42'});
       expect(request.contentLength, 3);
     });
 
-    test("is null for a chunked transfer encoding", () {
+    test('is null for a chunked transfer encoding', () {
       var request = _createMessage(
-          body: "1\r\na0\r\n\r\n", headers: {'transfer-encoding': 'chunked'});
+          body: '1\r\na0\r\n\r\n', headers: {'transfer-encoding': 'chunked'});
       expect(request.contentLength, isNull);
     });
 
-    test("is null for a non-identity transfer encoding", () {
+    test('is null for a non-identity transfer encoding', () {
       var request = _createMessage(
-          body: "1\r\na0\r\n\r\n", headers: {'transfer-encoding': 'custom'});
+          body: '1\r\na0\r\n\r\n', headers: {'transfer-encoding': 'custom'});
       expect(request.contentLength, isNull);
     });
 
-    test("is set for identity transfer encoding", () {
+    test('is set for identity transfer encoding', () {
       var request = _createMessage(
-          body: "1\r\na0\r\n\r\n", headers: {'transfer-encoding': 'identity'});
+          body: '1\r\na0\r\n\r\n', headers: {'transfer-encoding': 'identity'});
       expect(request.contentLength, equals(9));
     });
   });
 
-  group("mimeType", () {
-    test("is null without a content-type header", () {
+  group('mimeType', () {
+    test('is null without a content-type header', () {
       expect(_createMessage().mimeType, isNull);
     });
 
-    test("comes from the content-type header", () {
+    test('comes from the content-type header', () {
       expect(_createMessage(headers: {'content-type': 'text/plain'}).mimeType,
           equals('text/plain'));
     });
@@ -245,24 +246,24 @@
     });
   });
 
-  group("encoding", () {
-    test("is null without a content-type header", () {
+  group('encoding', () {
+    test('is null without a content-type header', () {
       expect(_createMessage().encoding, isNull);
     });
 
-    test("is null without a charset parameter", () {
+    test('is null without a charset parameter', () {
       expect(_createMessage(headers: {'content-type': 'text/plain'}).encoding,
           isNull);
     });
 
-    test("is null with an unrecognized charset parameter", () {
+    test('is null with an unrecognized charset parameter', () {
       expect(
           _createMessage(
               headers: {'content-type': 'text/plain; charset=fblthp'}).encoding,
           isNull);
     });
 
-    test("comes from the content-type charset parameter", () {
+    test('comes from the content-type charset parameter', () {
       expect(
           _createMessage(
                   headers: {'content-type': 'text/plain; charset=iso-8859-1'})
@@ -270,7 +271,7 @@
           equals(latin1));
     });
 
-    test("comes from the content-type charset parameter with a different case",
+    test('comes from the content-type charset parameter with a different case',
         () {
       expect(
           _createMessage(
@@ -279,50 +280,50 @@
           equals(latin1));
     });
 
-    test("defaults to encoding a String as UTF-8", () {
+    test('defaults to encoding a String as UTF-8', () {
       expect(
-          _createMessage(body: "è").read().toList(),
+          _createMessage(body: 'è').read().toList(),
           completion(equals([
             [195, 168]
           ])));
     });
 
-    test("uses the explicit encoding if available", () {
+    test('uses the explicit encoding if available', () {
       expect(
-          _createMessage(body: "è", encoding: latin1).read().toList(),
+          _createMessage(body: 'è', encoding: latin1).read().toList(),
           completion(equals([
             [232]
           ])));
     });
 
-    test("adds an explicit encoding to the content-type", () {
+    test('adds an explicit encoding to the content-type', () {
       var request = _createMessage(
-          body: "è", encoding: latin1, headers: {'content-type': 'text/plain'});
+          body: 'è', encoding: latin1, headers: {'content-type': 'text/plain'});
       expect(request.headers,
           containsPair('content-type', 'text/plain; charset=iso-8859-1'));
     });
 
-    test("adds an explicit encoding to the content-type with a different case",
+    test('adds an explicit encoding to the content-type with a different case',
         () {
       var request = _createMessage(
-          body: "è", encoding: latin1, headers: {'Content-Type': 'text/plain'});
+          body: 'è', encoding: latin1, headers: {'Content-Type': 'text/plain'});
       expect(request.headers,
           containsPair('Content-Type', 'text/plain; charset=iso-8859-1'));
     });
 
     test(
-        "sets an absent content-type to application/octet-stream in order to "
-        "set the charset", () {
-      var request = _createMessage(body: "è", encoding: latin1);
+        'sets an absent content-type to application/octet-stream in order to '
+        'set the charset', () {
+      var request = _createMessage(body: 'è', encoding: latin1);
       expect(
           request.headers,
           containsPair(
               'content-type', 'application/octet-stream; charset=iso-8859-1'));
     });
 
-    test("overwrites an existing charset if given an explicit encoding", () {
+    test('overwrites an existing charset if given an explicit encoding', () {
       var request = _createMessage(
-          body: "è",
+          body: 'è',
           encoding: latin1,
           headers: {'content-type': 'text/plain; charset=whatever'});
       expect(request.headers,
diff --git a/test/pipeline_test.dart b/test/pipeline_test.dart
index 20b601a..c697e0c 100644
--- a/test/pipeline_test.dart
+++ b/test/pipeline_test.dart
@@ -9,7 +9,7 @@
 
 void main() {
   test('compose middleware with Pipeline', () {
-    int accessLocation = 0;
+    var accessLocation = 0;
 
     var middlewareA = createMiddleware(requestHandler: (request) {
       expect(accessLocation, 0);
@@ -47,7 +47,7 @@
   });
 
   test('Pipeline can be used as middleware', () {
-    int accessLocation = 0;
+    var accessLocation = 0;
 
     var middlewareA = createMiddleware(requestHandler: (request) {
       expect(accessLocation, 0);
diff --git a/test/request_test.dart b/test/request_test.dart
index 6febec0..96c14e7 100644
--- a/test/request_test.dart
+++ b/test/request_test.dart
@@ -11,7 +11,7 @@
 import 'test_util.dart';
 
 Request _request({Map<String, String> headers, body, Encoding encoding}) {
-  return Request("GET", localhostUri,
+  return Request('GET', localhostUri,
       headers: headers, body: body, encoding: encoding);
 }
 
@@ -27,65 +27,65 @@
       expect(request.protocolVersion, '1.0');
     });
 
-    group("url", () {
+    group('url', () {
       test("defaults to the requestedUri's relativized path and query", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"));
-        expect(request.url, equals(Uri.parse("foo/bar?q=1")));
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'));
+        expect(request.url, equals(Uri.parse('foo/bar?q=1')));
       });
 
-      test("is inferred from handlerPath if possible", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
+      test('is inferred from handlerPath if possible', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
             handlerPath: '/foo/');
-        expect(request.url, equals(Uri.parse("bar?q=1")));
+        expect(request.url, equals(Uri.parse('bar?q=1')));
       });
 
-      test("uses the given value if passed", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
-            url: Uri.parse("bar?q=1"));
-        expect(request.url, equals(Uri.parse("bar?q=1")));
+      test('uses the given value if passed', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
+            url: Uri.parse('bar?q=1'));
+        expect(request.url, equals(Uri.parse('bar?q=1')));
       });
 
-      test("may be empty", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar"),
-            url: Uri.parse(""));
-        expect(request.url, equals(Uri.parse("")));
+      test('may be empty', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar'),
+            url: Uri.parse(''));
+        expect(request.url, equals(Uri.parse('')));
       });
     });
 
-    group("handlerPath", () {
+    group('handlerPath', () {
       test("defaults to '/'", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar"));
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar'));
         expect(request.handlerPath, equals('/'));
       });
 
-      test("is inferred from url if possible", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
-            url: Uri.parse("bar?q=1"));
-        expect(request.handlerPath, equals("/foo/"));
+      test('is inferred from url if possible', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
+            url: Uri.parse('bar?q=1'));
+        expect(request.handlerPath, equals('/foo/'));
       });
 
-      test("uses the given value if passed", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
+      test('uses the given value if passed', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
             handlerPath: '/foo/');
-        expect(request.handlerPath, equals("/foo/"));
+        expect(request.handlerPath, equals('/foo/'));
       });
 
-      test("adds a trailing slash to the given value if necessary", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
+      test('adds a trailing slash to the given value if necessary', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
             handlerPath: '/foo');
-        expect(request.handlerPath, equals("/foo/"));
-        expect(request.url, equals(Uri.parse("bar?q=1")));
+        expect(request.handlerPath, equals('/foo/'));
+        expect(request.url, equals(Uri.parse('bar?q=1')));
       });
 
-      test("may be a single slash", () {
-        var request = Request('GET', Uri.parse("http://localhost/foo/bar?q=1"),
+      test('may be a single slash', () {
+        var request = Request('GET', Uri.parse('http://localhost/foo/bar?q=1'),
             handlerPath: '/');
-        expect(request.handlerPath, equals("/"));
-        expect(request.url, equals(Uri.parse("foo/bar?q=1")));
+        expect(request.handlerPath, equals('/'));
+        expect(request.url, equals(Uri.parse('foo/bar?q=1')));
       });
     });
 
-    group("errors", () {
+    group('errors', () {
       group('requestedUri', () {
         test('must be absolute', () {
           expect(() => Request('GET', Uri.parse('/path')), throwsArgumentError);
@@ -182,17 +182,17 @@
     });
   });
 
-  group("ifModifiedSince", () {
-    test("is null without an If-Modified-Since header", () {
+  group('ifModifiedSince', () {
+    test('is null without an If-Modified-Since header', () {
       var request = _request();
       expect(request.ifModifiedSince, isNull);
     });
 
-    test("comes from the Last-Modified header", () {
+    test('comes from the Last-Modified header', () {
       var request = _request(
           headers: {'if-modified-since': 'Sun, 06 Nov 1994 08:49:37 GMT'});
       expect(request.ifModifiedSince,
-          equals(DateTime.parse("1994-11-06 08:49:37z")));
+          equals(DateTime.parse('1994-11-06 08:49:37z')));
     });
   });
 
@@ -267,7 +267,7 @@
       });
     });
 
-    test("allows the original request to be read", () {
+    test('allows the original request to be read', () {
       var request = _request();
       var changed = request.change();
 
@@ -275,7 +275,7 @@
       expect(changed.read, throwsStateError);
     });
 
-    test("allows the changed request to be read", () {
+    test('allows the changed request to be read', () {
       var request = _request();
       var changed = request.change();
 
@@ -283,7 +283,7 @@
       expect(request.read, throwsStateError);
     });
 
-    test("allows another changed request to be read", () {
+    test('allows another changed request to be read', () {
       var request = _request();
       var changed1 = request.change();
       var changed2 = request.change();
diff --git a/test/response_test.dart b/test/response_test.dart
index d316a4d..5d2149b 100644
--- a/test/response_test.dart
+++ b/test/response_test.dart
@@ -11,25 +11,25 @@
 import 'test_util.dart';
 
 void main() {
-  group("supports a String body", () {
-    test("readAsString", () {
-      var response = Response.ok("hello, world");
-      expect(response.readAsString(), completion(equals("hello, world")));
+  group('supports a String body', () {
+    test('readAsString', () {
+      var response = Response.ok('hello, world');
+      expect(response.readAsString(), completion(equals('hello, world')));
     });
 
-    test("read", () {
+    test('read', () {
       var helloWorldBytes = List.from(helloBytes)..addAll(worldBytes);
 
-      var response = Response.ok("hello, world");
+      var response = Response.ok('hello, world');
       expect(response.read().toList(), completion(equals([helloWorldBytes])));
     });
   });
 
-  group("new Response.internalServerError without a body", () {
+  group('new Response.internalServerError without a body', () {
     test('sets the body to "Internal Server Error"', () {
       var response = Response.internalServerError();
       expect(
-          response.readAsString(), completion(equals("Internal Server Error")));
+          response.readAsString(), completion(equals('Internal Server Error')));
     });
 
     test('sets the content-type header to text/plain', () {
@@ -46,42 +46,42 @@
     });
   });
 
-  group("Response redirect", () {
-    test("sets the location header for a String", () {
+  group('Response redirect', () {
+    test('sets the location header for a String', () {
       var response = Response.found('/foo');
       expect(response.headers, containsPair('location', '/foo'));
     });
 
-    test("sets the location header for a Uri", () {
+    test('sets the location header for a Uri', () {
       var response = Response.found(Uri(path: '/foo'));
       expect(response.headers, containsPair('location', '/foo'));
     });
   });
 
-  group("expires", () {
-    test("is null without an Expires header", () {
-      expect(Response.ok("okay!").expires, isNull);
+  group('expires', () {
+    test('is null without an Expires header', () {
+      expect(Response.ok('okay!').expires, isNull);
     });
 
-    test("comes from the Expires header", () {
+    test('comes from the Expires header', () {
       expect(
-          Response.ok("okay!",
+          Response.ok('okay!',
               headers: {'expires': 'Sun, 06 Nov 1994 08:49:37 GMT'}).expires,
-          equals(DateTime.parse("1994-11-06 08:49:37z")));
+          equals(DateTime.parse('1994-11-06 08:49:37z')));
     });
   });
 
-  group("lastModified", () {
-    test("is null without a Last-Modified header", () {
-      expect(Response.ok("okay!").lastModified, isNull);
+  group('lastModified', () {
+    test('is null without a Last-Modified header', () {
+      expect(Response.ok('okay!').lastModified, isNull);
     });
 
-    test("comes from the Last-Modified header", () {
+    test('comes from the Last-Modified header', () {
       expect(
-          Response.ok("okay!",
+          Response.ok('okay!',
                   headers: {'last-modified': 'Sun, 06 Nov 1994 08:49:37 GMT'})
               .lastModified,
-          equals(DateTime.parse("1994-11-06 08:49:37z")));
+          equals(DateTime.parse('1994-11-06 08:49:37z')));
     });
   });
 
@@ -111,7 +111,7 @@
       });
     });
 
-    test("allows the original response to be read", () {
+    test('allows the original response to be read', () {
       var response = Response.ok(null);
       var changed = response.change();
 
@@ -119,7 +119,7 @@
       expect(changed.read, throwsStateError);
     });
 
-    test("allows the changed response to be read", () {
+    test('allows the changed response to be read', () {
       var response = Response.ok(null);
       var changed = response.change();
 
@@ -127,7 +127,7 @@
       expect(response.read, throwsStateError);
     });
 
-    test("allows another changed response to be read", () {
+    test('allows another changed response to be read', () {
       var response = Response.ok(null);
       var changed1 = response.change();
       var changed2 = response.change();
diff --git a/test/server_handler_test.dart b/test/server_handler_test.dart
index 8a23b51..f42b361 100644
--- a/test/server_handler_test.dart
+++ b/test/server_handler_test.dart
@@ -11,12 +11,12 @@
 import 'test_util.dart';
 
 void main() {
-  test("passes the URL to the server", () {
+  test('passes the URL to the server', () {
     var serverHandler = ServerHandler(localhostUri);
     expect(serverHandler.server.url, equals(localhostUri));
   });
 
-  test("pipes a request from ServerHandler.handler to a mounted handler",
+  test('pipes a request from ServerHandler.handler to a mounted handler',
       () async {
     var serverHandler = ServerHandler(localhostUri);
     serverHandler.server.mount(asyncHandler);
@@ -38,7 +38,7 @@
     expect(response.readAsString(), completion(equals('Hello from /')));
   });
 
-  test("stops servicing requests after Server.close is called", () {
+  test('stops servicing requests after Server.close is called', () {
     var serverHandler = ServerHandler(localhostUri);
     serverHandler.server.mount(expectAsync1((_) => null, count: 0));
     serverHandler.server.close();
@@ -46,7 +46,7 @@
     expect(makeSimpleRequest(serverHandler.handler), throwsStateError);
   });
 
-  test("calls onClose when Server.close is called", () async {
+  test('calls onClose when Server.close is called', () async {
     var onCloseCalled = false;
     var completer = Completer();
     var serverHandler = ServerHandler(localhostUri, onClose: () {
diff --git a/test/shelf_io_test.dart b/test/shelf_io_test.dart
index fd69efd..25a9875 100644
--- a/test/shelf_io_test.dart
+++ b/test/shelf_io_test.dart
@@ -206,24 +206,24 @@
       expect(request.method, 'POST');
 
       request.hijack(expectAsync1((channel) {
-        expect(channel.stream.first, completion(equals("Hello".codeUnits)));
+        expect(channel.stream.first, completion(equals('Hello'.codeUnits)));
 
-        channel.sink.add(("HTTP/1.1 404 Not Found\r\n"
-                "Date: Mon, 23 May 2005 22:38:34 GMT\r\n"
-                "Content-Length: 13\r\n"
-                "\r\n"
-                "Hello, world!")
+        channel.sink.add(('HTTP/1.1 404 Not Found\r\n'
+                'Date: Mon, 23 May 2005 22:38:34 GMT\r\n'
+                'Content-Length: 13\r\n'
+                '\r\n'
+                'Hello, world!')
             .codeUnits);
         channel.sink.close();
       }));
       return null;
     });
 
-    var response = await _post(body: "Hello");
+    var response = await _post(body: 'Hello');
     expect(response.statusCode, HttpStatus.notFound);
-    expect(response.headers["date"], "Mon, 23 May 2005 22:38:34 GMT");
+    expect(response.headers['date'], 'Mon, 23 May 2005 22:38:34 GMT');
     expect(
-        response.stream.bytesToString(), completion(equals("Hello, world!")));
+        response.stream.bytesToString(), completion(equals('Hello, world!')));
   });
 
   test('reports an error if a HijackException is thrown without hijacking',
@@ -387,14 +387,14 @@
         () async {
       await _scheduleServer((request) {
         return Response.ok(
-            Stream.fromIterable(["2\r\nhi\r\n0\r\n\r\n".codeUnits]),
+            Stream.fromIterable(['2\r\nhi\r\n0\r\n\r\n'.codeUnits]),
             headers: {HttpHeaders.transferEncodingHeader: 'chunked'});
       });
 
       var response = await _get();
       expect(response.headers,
           containsPair(HttpHeaders.transferEncodingHeader, 'chunked'));
-      expect(response.body, equals("hi"));
+      expect(response.body, equals('hi'));
     });
 
     group('is not added when', () {
@@ -451,24 +451,24 @@
   test('respects the "shelf.io.buffer_output" context parameter', () async {
     var controller = StreamController<String>();
     await _scheduleServer((request) {
-      controller.add("Hello, ");
+      controller.add('Hello, ');
 
       return Response.ok(utf8.encoder.bind(controller.stream),
-          context: {"shelf.io.buffer_output": false});
+          context: {'shelf.io.buffer_output': false});
     });
 
     var request =
-        http.Request("GET", Uri.parse('http://localhost:$_serverPort/'));
+        http.Request('GET', Uri.parse('http://localhost:$_serverPort/'));
 
     var response = await request.send();
     var stream = StreamQueue(utf8.decoder.bind(response.stream));
 
     var data = await stream.next;
-    expect(data, equals("Hello, "));
-    controller.add("world!");
+    expect(data, equals('Hello, '));
+    controller.add('world!');
 
     data = await stream.next;
-    expect(data, equals("world!"));
+    expect(data, equals('world!'));
     await controller.close();
     expect(stream.hasNext, completion(isFalse));
   });
diff --git a/test/ssl_certs.dart b/test/ssl_certs.dart
index be86de3..d5a3625 100644
--- a/test/ssl_certs.dart
+++ b/test/ssl_certs.dart
@@ -4,7 +4,7 @@
 
 import 'dart:convert';
 
-List<int> certChainBytes = utf8.encode("""
+List<int> certChainBytes = utf8.encode('''
 -----BEGIN CERTIFICATE-----
 MIIDZDCCAkygAwIBAgIBATANBgkqhkiG9w0BAQsFADAgMR4wHAYDVQQDDBVpbnRl
 cm1lZGlhdGVhdXRob3JpdHkwHhcNMTUxMDI3MTAyNjM1WhcNMjUxMDI0MTAyNjM1
@@ -64,9 +64,9 @@
 UnlU2l5vZrh1PTCqZxvC/IdRESUfW80LdHaeyizRUP+6vKxGgSz2MRuYINjbd6GO
 hGiCpWlwziW2xLV1l2qSRLko2kIafLZP18N0ThM9zKbU5ps9NgFOf//wqSGtLaE=
 -----END CERTIFICATE-----
-""");
+''');
 
-List<int> certKeyBytes = utf8.encode("""
+List<int> certKeyBytes = utf8.encode('''
 -----BEGIN ENCRYPTED PRIVATE KEY-----
 MIIE4zAcBgoqhkiG9w0BDAEBMA4ECBMCjlg8JYZ4AgIIAASCBMFd9cBoZ5xcTock
 AVQcg/HzYJtMceKn1gtMDdC7mmXuyN0shoxhG4BpQInHkFARL+nenesXFxEm4X5e
@@ -96,4 +96,4 @@
 s0HRA2VwF/0ypU3OKERM1Ua5NSkTgvnnVTlV9GO90Tkn5v4fxdl8NzIuJLyGguTP
 Xc0tRM34Lg==
 -----END ENCRYPTED PRIVATE KEY-----
-""");
+''');
diff --git a/test/test_util.dart b/test/test_util.dart
index 8af96fa..9d0f46d 100644
--- a/test/test_util.dart
+++ b/test/test_util.dart
@@ -21,8 +21,7 @@
 /// `Hello from ${request.url.path}`.
 Response syncHandler(Request request,
     {int statusCode, Map<String, String> headers}) {
-  if (statusCode == null) statusCode = 200;
-  return Response(statusCode,
+  return Response(statusCode ?? 200,
       headers: headers, body: 'Hello from ${request.requestedUri.path}');
 }