Make failing HTTP requests thrown when using dart:io.

test/loader_http_test.dart

 // Copyright (c) 2015, 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.
 
 @TestOn("vm")
 
 import "dart:convert";
 import "dart:io";
 
 import "package:resource/resource.dart";
 import "package:test/test.dart";
 
 const content = "Rødgrød med fløde";
 
 main() {
   var server;
   var uri;
   setUp(() async {
     server = await HttpServer.bind(InternetAddress.LOOPBACK_IP_V4, 0);
     int port = server.port;
     uri = Uri.parse("http://localhost:$port/default.html");
     server.forEach((HttpRequest request) {
+      if (request.uri.path.endsWith(".not")) {
+        request.response
+          ..statusCode = HttpStatus.NOT_FOUND
+          ..close();
+        return;
+      }
       var encodings = request.headers[HttpHeaders.ACCEPT_CHARSET];
       var encoding = parseAcceptCharset(encodings);
       request.response.headers.contentType =
           new ContentType("text", "plain", charset: encoding.name);
       request.response..write(content)
                       ..close();
     }).catchError(print);
   });
 
   test("Default encoding", () async {
@@ skipping 21 matching lines @@
   });
 
   test("byte stream", () async {
     var loader = ResourceLoader.defaultLoader;
     var bytes = loader.openRead(uri);  // Sender uses Latin-1.
     var buffer = [];
     await bytes.forEach(buffer.addAll);
     expect(buffer, content.codeUnits);
   });
 
+  test("not found - String", () async {
+    var loader = ResourceLoader.defaultLoader;
+    var badUri = uri.resolve("file.not");  // .not makes server fail.
+    expect(loader.readAsString(badUri), throws);
+  });
+
+  test("not found - bytes", () async {
+    var loader = ResourceLoader.defaultLoader;
+    var badUri = uri.resolve("file.not");  // .not makes server fail.
+    expect(loader.readAsBytes(badUri), throws);
+  });
+
+  test("not found - byte stream", () async {
+    var loader = ResourceLoader.defaultLoader;
+    var badUri = uri.resolve("file.not");  // .not makes server fail.
+    expect(loader.openRead(badUri).length, throws);
+  });
+
   tearDown(() {
     server.close();
     server = null;
   });
 }
 
 
 Encoding parseAcceptCharset(List<String> headers) {
   var encoding = LATIN1;
   if (headers != null) {
     var weight = 0.0;
     var pattern = new RegExp(r"([\w-]+)(;\s*q=[\d.]+)?");
     for (var acceptCharset in headers) {
       for (var match in pattern.allMatches(acceptCharset)) {
         var e = Encoding.getByName(match[1]);
         if (e == null) continue;
         var w = 1.0;
         if (match[2] != null) {
           w = double.parse(match[2]);
         }
         if (w > weight) {
           weight = w;
           encoding = e;
         }
       }
     }
   }
   return encoding;
 }