Better checking and error reporting for HTTP client

runtime/bin/http_impl.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.
 
 class _HttpHeaders implements HttpHeaders {
   _HttpHeaders() : _headers = new Map<String, List<String>>();
 
   List<String> operator[](String name) {
     name = name.toLowerCase();
     return _headers[name];
@@ skipping 1244 matching lines @@
 
   DetachedSocket detachSocket() {
     return _detachSocket();
   }
 
   void _onConnectionClosed(e) {
     // Socket is closed either due to an error or due to normal socket close.
     if (e != null) {
       if (_onErrorCallback != null) {
         _onErrorCallback(e);
+      } else {
+        throw e;
       }
     }
     _closing = true;
     if (e != null) {
       // Propagate the error to the streams.
       if (_response != null && _response._streamErrorHandler != null) {
         _response._streamErrorHandler(e);
       }
       _responseDone();
     } else {
@@ skipping 84 matching lines @@
 class _HttpClient implements HttpClient {
   static final int DEFAULT_EVICTION_TIMEOUT = 60000;
 
   _HttpClient() : _openSockets = new Map(),
                   _activeSockets = new Set(),
                   _shutdown = false;
 
   HttpClientConnection open(
       String method, String host, int port, String path) {
     if (_shutdown) throw new HttpException("HttpClient shutdown");
+    if (method == null || host == null || port == null || path == null) {
+      throw new NullPointerException();

[Mads Ager (google), 2012/05/03 13:36:28]

We could throw a more descriptive error here? Not sure it matters much so I'll
leave it up to you.

Is null the only thing we need to check here because other checks are done
later?

[Søren Gjesse, 2012/05/07 11:42:31]

Changed to IllegalArgumentException.

Arguments are type checked later.

+    }
     return _prepareHttpClientConnection(host, port, method, path);
   }
 
   HttpClientConnection openUrl(String method, Uri url) {
     if (url.scheme != "http") {
       throw new HttpException("Unsupported URL scheme ${url.scheme}");
     }
     if (url.userInfo != "") {
       throw new HttpException("Unsupported user info ${url.userInfo}");
     }
@@ skipping 155 matching lines @@
 }
 
 
 class _DetachedSocket implements DetachedSocket {
   _DetachedSocket(this._socket, this._unparsedData);
   Socket get socket() => _socket;
   List<int> get unparsedData() => _unparsedData;
   Socket _socket;
   List<int> _unparsedData;
 }