I have a client program based on LibCurl. I have run into a situation where on some occasions a program on the server runs longer than the configured IIS timeout. IIS then terminates the program and returns a 502 error status to the client.
I have added code to the client to capture this issue. Now, I need to find a way to prove that the change will work.
I haven't been able to reliably reproduce the issue, so don't have a good test case.
Any suggestions?
I've seen plenty of tests that spin up a private web server for the duration of the test, with the private web server provided with a script of expected requests and responses. The bit of the client under test hits the private web server, and tests verify the expected client behavior.
You probably don't need a full-blown IIS, just something that acts enough like one to deliver the right responses. Pick a language, and you'll find a library (and probably demos) for putting together a simple web server.
This shows you, in a very simple way, how to embed a worker process in an NUnit fixture.
You can then serve up as many errors as you like.
Here is a sample fixture:
using System.Net;
using NUnit.Framework;
namespace Salient.Excerpts
{
[TestFixture]
public class WebHostServerFixture : WebHostServer
{
[TestFixtureSetUp]
public void TestFixtureSetUp()
{
StartServer(@"..\..\..\..\TestSite");
// is the equivalent of
// StartServer(@"..\..\..\..\TestSite",
// GetAvailablePort(8000, 10000, IPAddress.Loopback, true), "/", "localhost");
}
[TestFixtureTearDown]
public void TestFixtureTearDown()
{
StopServer();
}
[Test]
public void Test()
{
// while a reference to the web app under test is not necessary,
// if you do add a reference to this test project you may F5 debug your tests.
// if you debug this test you will break in Default.aspx.cs
string html = new WebClient().DownloadString(NormalizeUri("Default.aspx"));
}
}
}
And here is the server:
// Project: Salient
// http://salient.codeplex.com
// Date: April 16 2010
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Threading;
using Microsoft.VisualStudio.WebHost;
namespace Salient.Excerpts
{
/// <summary>
/// A general purpose Microsoft.VisualStudio.WebHost.Server test fixture.
/// WebHost.Server is the core of the Visual Studio Development Server (WebDev.WebServer).
///
/// This server is run in-process and may be used in F5 debugging.
/// </summary>
/// <remarks>
/// If you are adding this source code to a new project, You will need to
/// manually add a reference to WebDev.WebHost.dll to your project. It cannot
/// be added from within Visual Studio.
///
/// Please see the Readme.txt accompanying this code for details.
/// </remarks>
/// NOTE: code from various namespaces/classes in the Salient project have been merged into this
/// single class for this post in the interest of brevity
public class WebHostServer
{
private Server _server;
public string ApplicationPath { get; private set; }
public string HostName { get; private set; }
public int Port { get; private set; }
public string VirtualPath { get; private set; }
public string RootUrl
{
get { return string.Format(CultureInfo.InvariantCulture, "http://{0}:{1}{2}", HostName, Port, VirtualPath); }
}
/// <summary>
/// Combine the RootUrl of the running web application with the relative url specified.
/// </summary>
public virtual Uri NormalizeUri(string relativeUrl)
{
return new Uri(RootUrl + relativeUrl);
}
/// <summary>
/// Will start "localhost" on first available port in the range 8000-10000 with vpath "/"
/// </summary>
/// <param name="applicationPath"></param>
public void StartServer(string applicationPath)
{
StartServer(applicationPath, GetAvailablePort(8000, 10000, IPAddress.Loopback, true), "/", "localhost");
}
/// <summary>
/// </summary>
/// <param name="applicationPath">Physical path to application.</param>
/// <param name="port">Port to listen on.</param>
/// <param name="virtualPath">Optional. defaults to "/"</param>
/// <param name="hostName">Optional. Is used to construct RootUrl. Defaults to "localhost"</param>
public void StartServer(string applicationPath, int port, string virtualPath, string hostName)
{
if (_server != null)
{
throw new InvalidOperationException("Server already started");
}
// WebHost.Server will not run on any other IP
IPAddress ipAddress = IPAddress.Loopback;
if(!IsPortAvailable(ipAddress, port))
{
throw new Exception(string.Format("Port {0} is in use.", port));
}
applicationPath = Path.GetFullPath(applicationPath);
virtualPath = String.Format("/{0}/", (virtualPath ?? string.Empty).Trim('/')).Replace("//", "/");
_server = new Server(port, virtualPath, applicationPath, false, false);
_server.Start();
ApplicationPath = applicationPath;
Port = port;
VirtualPath = virtualPath;
HostName = string.IsNullOrEmpty(hostName) ? "localhost" : hostName;
}
/// <summary>
/// Stops the server.
/// </summary>
public void StopServer()
{
if (_server != null)
{
_server.Stop();
_server = null;
// allow some time to release the port
Thread.Sleep(100);
}
}
public void Dispose()
{
StopServer();
}
/// <summary>
/// Gently polls specified IP:Port to determine if it is available.
/// </summary>
/// <param name="ipAddress"></param>
/// <param name="port"></param>
public static bool IsPortAvailable(IPAddress ipAddress, int port)
{
bool portAvailable = false;
for (int i = 0; i < 5; i++)
{
portAvailable = GetAvailablePort(port, port, ipAddress, true) == port;
if (portAvailable)
{
break;
}
// be a little patient and wait for the port if necessary,
// the previous occupant may have just vacated
Thread.Sleep(100);
}
return portAvailable;
}
/// <summary>
/// Returns first available port on the specified IP address.
/// The port scan excludes ports that are open on ANY loopback adapter.
///
/// If the address upon which a port is requested is an 'ANY' address all
/// ports that are open on ANY IP are excluded.
/// </summary>
/// <param name="rangeStart"></param>
/// <param name="rangeEnd"></param>
/// <param name="ip">The IP address upon which to search for available port.</param>
/// <param name="includeIdlePorts">If true includes ports in TIME_WAIT state in results.
/// TIME_WAIT state is typically cool down period for recently released ports.</param>
/// <returns></returns>
public static int GetAvailablePort(int rangeStart, int rangeEnd, IPAddress ip, bool includeIdlePorts)
{
IPGlobalProperties ipProps = IPGlobalProperties.GetIPGlobalProperties();
// if the ip we want a port on is an 'any' or loopback port we need to exclude all ports that are active on any IP
Func<IPAddress, bool> isIpAnyOrLoopBack = i => IPAddress.Any.Equals(i) ||
IPAddress.IPv6Any.Equals(i) ||
IPAddress.Loopback.Equals(i) ||
IPAddress.IPv6Loopback.
Equals(i);
// get all active ports on specified IP.
List<ushort> excludedPorts = new List<ushort>();
// if a port is open on an 'any' or 'loopback' interface then include it in the excludedPorts
excludedPorts.AddRange(from n in ipProps.GetActiveTcpConnections()
where
n.LocalEndPoint.Port >= rangeStart &&
n.LocalEndPoint.Port <= rangeEnd && (
isIpAnyOrLoopBack(ip) || n.LocalEndPoint.Address.Equals(ip) ||
isIpAnyOrLoopBack(n.LocalEndPoint.Address)) &&
(!includeIdlePorts || n.State != TcpState.TimeWait)
select (ushort)n.LocalEndPoint.Port);
excludedPorts.AddRange(from n in ipProps.GetActiveTcpListeners()
where n.Port >= rangeStart && n.Port <= rangeEnd && (
isIpAnyOrLoopBack(ip) || n.Address.Equals(ip) || isIpAnyOrLoopBack(n.Address))
select (ushort)n.Port);
excludedPorts.AddRange(from n in ipProps.GetActiveUdpListeners()
where n.Port >= rangeStart && n.Port <= rangeEnd && (
isIpAnyOrLoopBack(ip) || n.Address.Equals(ip) || isIpAnyOrLoopBack(n.Address))
select (ushort)n.Port);
excludedPorts.Sort();
for (int port = rangeStart; port <= rangeEnd; port++)
{
if (!excludedPorts.Contains((ushort)port))
{
return port;
}
}
return 0;
}
}
}
One caveat:
NOTE: The Microsoft.VisualStudio.WebHost namespace is contained in the file WebDev.WebHost.dll. This file is in the GAC but it is not possible to add a reference to this assembly from within Visual Studio.
To add a reference you will need to open your .csproj file in a text editor and add the reference manually.
Look for the ItemGroup that contains the project references and add the following element:
<Reference Include="WebDev.WebHost, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=x86">
<Private>False</Private>
</Reference>
Reference: http://www.codeproject.com/KB/aspnet/test-with-vs-devserver-2.aspx