Add redirect support to the HTTP client

tests/standalone/io/http_redirect_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:io");
+#import("dart:uri");
+
+HttpServer setupServer() {
+  HttpServer server = new HttpServer();
+  server.listen("127.0.0.1", 0, 5);
+
+  void addRedirectHandler(int number, int statusCode) {
+    server.addRequestHandler(
+       (HttpRequest request) => request.path == "/$number",
+       (HttpRequest request, HttpResponse response) {
+       response.headers.set(HttpHeaders.LOCATION,
+                            "http://127.0.0.1:${server.port}/${number + 1}");
+       response.statusCode = statusCode;
+       response.outputStream.close();
+     });
+  }
+
+  // Setup redirect chain.
+  int n = 1;
+  addRedirectHandler(n++, HttpStatus.MOVED_PERMANENTLY);
+  addRedirectHandler(n++, HttpStatus.MOVED_TEMPORARILY);
+  addRedirectHandler(n++, HttpStatus.SEE_OTHER);
+  addRedirectHandler(n++, HttpStatus.TEMPORARY_REDIRECT);
+  for (int i = n; i < 10; i++) {
+    addRedirectHandler(i, HttpStatus.MOVED_PERMANENTLY);
+  }
+
+  // Setup redirect loop.
+  server.addRequestHandler(
+     (HttpRequest request) => request.path == "/A",
+     (HttpRequest request, HttpResponse response) {
+       response.headers.set(HttpHeaders.LOCATION,
+                            "http://127.0.0.1:${server.port}/B");
+       response.statusCode = HttpStatus.MOVED_PERMANENTLY;
+       response.outputStream.close();
+     }
+  );
+  server.addRequestHandler(
+     (HttpRequest request) => request.path == "/B",
+     (HttpRequest request, HttpResponse response) {
+       response.headers.set(HttpHeaders.LOCATION,
+                            "http://127.0.0.1:${server.port}/A");
+       response.statusCode = HttpStatus.MOVED_TEMPORARILY;
+       response.outputStream.close();
+     }
+  );
+
+  return server;
+}
+
+void checkRedirects(int redirectCount, HttpClientConnection conn) {
+  if (redirectCount < 2) {
+    Expect.isNull(conn.redirects);
+  } else {
+    Expect.equals(redirectCount - 1, conn.redirects.length);
+    for (int i = 0; i < redirectCount - 2; i++) {
+      Expect.equals(conn.redirects[i].location.path, "/${i + 2}");
+    }
+  }
+}
+
+void testManualRedirect() {
+  HttpServer server = setupServer();
+  HttpClient client = new HttpClient();
+
+  int redirectCount = 0;
+  HttpClientConnection conn =
+     client.getUrl(new Uri.fromString("http://127.0.0.1:${server.port}/1"));
+  conn.followRedirects = false;
+  conn.onResponse = (HttpClientResponse response) {
+    response.inputStream.onData = () => response.inputStream.read();
+    response.inputStream.onClosed = () {
+      redirectCount++;
+      if (redirectCount < 10) {
+        Expect.isTrue(response.isRedirect);
+        checkRedirects(redirectCount, conn);
+        conn.redirect();
+      } else {
+        Expect.equals(HttpStatus.NOT_FOUND, response.statusCode);
+        server.close();
+        client.shutdown();
+      }
+    };
+  };
+}
+
+void testAutoRedirect() {
+  HttpServer server = setupServer();
+  HttpClient client = new HttpClient();
+
+  HttpClientConnection conn =
+      client.getUrl(new Uri.fromString("http://127.0.0.1:${server.port}/1"));
+  conn.onResponse = (HttpClientResponse response) {
+    response.inputStream.onData = () => Expect.fail("Response not expected");
+    response.inputStream.onClosed = () => Expect.fail("Response not expected");
+  };
+  conn.onError = (e) {
+    Expect.isTrue(e is RedirectLimitExceeded);
+    Expect.equals(5, e.redirects.length);
+    server.close();
+    client.shutdown();
+  };
+}
+
+void testRedirectLoop() {
+  HttpServer server = setupServer();
+  HttpClient client = new HttpClient();
+
+  int redirectCount = 0;
+  HttpClientConnection conn =
+      client.getUrl(new Uri.fromString("http://127.0.0.1:${server.port}/A"));
+  conn.onResponse = (HttpClientResponse response) {
+    response.inputStream.onData = () => Expect.fail("Response not expected");
+    response.inputStream.onClosed = () => Expect.fail("Response not expected");
+  };
+  conn.onError = (e) {
+    Expect.isTrue(e is RedirectLoop);
+    Expect.equals(2, e.redirects.length);
+    server.close();
+    client.shutdown();
+  };
+}
+
+main() {
+  testManualRedirect();
+  testAutoRedirect();
+  testRedirectLoop();
+}