Improve the handling of the connection header

tests/standalone/io/http_connection_header_test.dart

+// Copyright (c) 2012, 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 setConnectionHeaders(HttpHeaders headers) {
+  headers.add(HttpHeaders.CONNECTION, "my-connection-header1");
+  headers.add("My-Connection-Header1", "some-value1");
+  headers.add(HttpHeaders.CONNECTION, "my-connection-header2");
+  headers.add("My-Connection-Header2", "some-value2");
+}
+
+void checkExpectedConnectionHeaders(HttpHeaders headers,
+                                    bool persistentConnection) {
+  Expect.equals("some-value1", headers.value("My-Connection-Header1"));
+  Expect.equals("some-value2", headers.value("My-Connection-Header2"));
+  Expect.isTrue(headers[HttpHeaders.CONNECTION].some(
+      (value) => value.toLowerCase() == "my-connection-header1"));
+  Expect.isTrue(headers[HttpHeaders.CONNECTION].some(
+      (value) => value.toLowerCase() == "my-connection-header2"));
+  if (persistentConnection) {
+    Expect.equals(2, headers[HttpHeaders.CONNECTION].length);
+  } else {
+    Expect.equals(3, headers[HttpHeaders.CONNECTION].length);
+    Expect.isTrue(headers[HttpHeaders.CONNECTION].some(
+        (value) => value.toLowerCase() == "close"));
+  }
+}
+
+void test(int totalConnections, bool clientPersistentConnection) {
+  HttpServer server = new HttpServer();
+  server.onError = (e) => Expect.fail("Unexpected error $e");
+  server.listen("127.0.0.1", 0, totalConnections);
+  server.defaultRequestHandler = (HttpRequest request, HttpResponse response) {
+    // Check expected request.
+    Expect.equals(clientPersistentConnection, request.persistentConnection);
+    Expect.equals(clientPersistentConnection, response.persistentConnection);
+    checkExpectedConnectionHeaders(request.headers,
+                                   request.persistentConnection);
+
+    // Generate response. If the client signaled non-persistent
+    // connection the server should not need to set it.
+    if (request.persistentConnection) {
+      response.persistentConnection = false;
+    }
+    setConnectionHeaders(response.headers);
+    response.outputStream.close();
+  };
+
+  int count = 0;
+  HttpClient client = new HttpClient();
+  for (int i = 0; i < totalConnections; i++) {
+    HttpClientConnection conn = client.get("127.0.0.1", server.port, "/");
+    conn.onError = (e) => Expect.fail("Unexpected error $e");
+    conn.onRequest = (HttpClientRequest request) {
+      setConnectionHeaders(request.headers);
+      request.persistentConnection = clientPersistentConnection;
+      request.outputStream.close();
+    };
+    conn.onResponse = (HttpClientResponse response) {
+      Expect.isFalse(response.persistentConnection);
+      checkExpectedConnectionHeaders(response.headers,
+                                     response.persistentConnection);
+      count++;
+      if (count == totalConnections) {
+        client.shutdown();
+        server.close();
+      }
+    };
+  }
+}
+
+
+void main() {
+  test(2, false);
+  test(2, true);
+}