Make IOSink implement StringSink

tests/standalone/io/http_content_length_test.dart

 // Copyright (c) 2013, 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.
 
 import "dart:isolate";
 import "dart:io";
 
 void testNoBody(int totalConnections, bool explicitContentLength) {
   var errors = 0;
   HttpServer.bind("127.0.0.1", 0, totalConnections).then((server) {
     server.listen(
         (HttpRequest request) {
           Expect.equals("0", request.headers.value('content-length'));
           Expect.equals(0, request.contentLength);
           var response = request.response;
           response.contentLength = 0;
           response.done
             .then((_) {
               Expect.fail("Unexpected successful response completion");
             })
             .catchError((e) {
               Expect.isTrue(e.error is HttpException);
             });
-          // addString with content length 0 closes the connection and
+          // write with content length 0 closes the connection and
           // reports an error.
-          response.addString("x");
-          // Subsequent addString are ignored as there is already an
+          response.write("x");
+          // Subsequent write are ignored as there is already an
           // error.
-          response.addString("x");
-          // After an explicit close, addString becomes a state error
+          response.write("x");
+          // After an explicit close, write becomes a state error
           // because we have said we will not add more.
           response.close();
-          Expect.throws(() => response.addString("x"),
+          Expect.throws(() => response.write("x"),
                         (e) => e is StateError);
         },
         onError: (e) {
           Expect.fail("Unexpected server error $e");
         });
 
     int count = 0;
     HttpClient client = new HttpClient();
     for (int i = 0; i < totalConnections; i++) {
       client.get("127.0.0.1", server.port, "/")
@@ skipping 31 matching lines @@
           Expect.equals(2, request.contentLength);
           var response = request.response;
           if (useHeader) {
             response.contentLength = 2;
           } else {
             response.headers.set("content-length", 2);
           }
           request.listen(
               (d) {},
               onDone: () {
-                response.addString("x");
+                response.write("x");
                 Expect.throws(() => response.contentLength = 3,
                               (e) => e is HttpException);
-                response.addString("x");
-                response.addString("x");
+                response.write("x");
+                response.write("x");
                 response.done
                     .then((_) {
                       Expect.fail("Unexpected successful response completion");
                     })
                     .catchError((e) {
                       Expect.isTrue(e.error is HttpException, "[$e]");
                       if (++serverCount == totalConnections) {
                         server.close();
                       }
                     });
                 response.close();
-                Expect.throws(() => response.addString("x"),
+                Expect.throws(() => response.write("x"),
                               (e) => e is StateError);
               });
         },
         onError: (e) => Expect.fail("Unexpected error $e"));
 
     int clientCount = 0;
     HttpClient client = new HttpClient();
     for (int i = 0; i < totalConnections; i++) {
       client.get("127.0.0.1", server.port, "/")
           .then((request) {
             if (useHeader) {
               request.contentLength = 2;
             } else {
               request.headers.add(HttpHeaders.CONTENT_LENGTH, "7");
               request.headers.add(HttpHeaders.CONTENT_LENGTH, "2");
             }
-            request.addString("x");
+            request.write("x");
             Expect.throws(() => request.contentLength = 3,
                           (e) => e is HttpException);
-            request.addString("x");
+            request.write("x");
             return request.close();
           })
           .then((response) {
             Expect.equals("2", response.headers.value('content-length'));
             Expect.equals(2, response.contentLength);
             response.listen(
                 (d) {},
                 onDone: () {
                   if (++clientCount == totalConnections) {
                     client.close();
@@ skipping 14 matching lines @@
           if (useHeader) {
             response.contentLength = 2;
             response.headers.chunkedTransferEncoding = true;
           } else {
             response.headers.set("content-length", 2);
             response.headers.set("transfer-encoding", "chunked");
           }
           request.listen(
               (d) {},
               onDone: () {
-                response.addString("x");
+                response.write("x");
                 Expect.throws(
                     () => response.headers.chunkedTransferEncoding = false,
                     (e) => e is HttpException);
-                response.addString("x");
-                response.addString("x");
+                response.write("x");
+                response.write("x");
                 response.close();
-                Expect.throws(() => response.addString("x"),
+                Expect.throws(() => response.write("x"),
                               (e) => e is StateError);
               });
         },
         onError: (e) => Expect.fail("Unexpected error $e"));
 
     int count = 0;
     HttpClient client = new HttpClient();
     for (int i = 0; i < totalConnections; i++) {
       client.get("127.0.0.1", server.port, "/")
           .then((request) {
             if (useHeader) {
               request.contentLength = 2;
               request.headers.chunkedTransferEncoding = true;
             } else {
               request.headers.add(HttpHeaders.CONTENT_LENGTH, "2");
               request.headers.set(HttpHeaders.TRANSFER_ENCODING, "chunked");
             }
-            request.addString("x");
+            request.write("x");
             Expect.throws(() => request.headers.chunkedTransferEncoding = false,
                           (e) => e is HttpException);
-            request.addString("x");
-            request.addString("x");
+            request.write("x");
+            request.write("x");
             return request.close();
           })
           .then((response) {
             Expect.isNull(response.headers.value('content-length'));
             Expect.equals(-1, response.contentLength);
             response.listen(
                 (d) {},
                 onDone: () {
                   if (++count == totalConnections) {
                     client.close();
                     server.close();
                   }
                 });
           })
           .catchError((e) => Expect.fail("Unexpected error $e"));
     }
   });
 }
 
 void testSetContentLength() {
   HttpServer.bind().then((server) {
     server.listen(
         (HttpRequest request) {
           var response = request.response;
           Expect.isNull(response.headers.value('content-length'));
           Expect.equals(-1, response.contentLength);
           response.headers.set("content-length", 3);
           Expect.equals("3", response.headers.value('content-length'));
           Expect.equals(3, response.contentLength);
-          response.addString("xxx");
+          response.write("xxx");
           response.close();
         });
 
     var client = new HttpClient();
     client.get("127.0.0.1", server.port, "/")
         .then((request) => request.close())
         .then((response) {
           response.listen(
               (_) { },
               onDone: () {
                 client.close();
                 server.close();
               });
         });
   });
 }
 
 void main() {
   testNoBody(5, false);
   testNoBody(5, true);
   testBody(5, false);
   testBody(5, true);
   testBodyChunked(5, false);
   testBodyChunked(5, true);
   testSetContentLength();
 }