下面显示了使上述案例可测试的潜在解决方法
public class XForwardedForRewriter : IHttpModule {
public void Dispose() {
throw new NotImplementedException();
}
byte[] proxyv2HeaderStartRequence = new byte[12] { 0x0D, 0x0A, 0x0D, 0x0A, 0x00, 0x0D, 0x0A, 0x51, 0x55, 0x49, 0x54, 0x0A };
public void Init(HttpApplication context) {
context.BeginRequest += Context_BeginRequest;
}
public Func<object, HttpRequestBase> GetRequest = (object sender) => {
return new HttpRequestWrapper(((HttpApplication)sender).Context.Request);
};
public void Context_BeginRequest(object sender, EventArgs e) {
var request = GetRequest(sender);
var proxyv2header = request.BinaryRead(12);
if (!proxyv2header.SequenceEqual(proxyv2HeaderStartRequence)) {
request.Abort();
} else {
var proxyv2IpvType = request.BinaryRead(5).Skip(1).Take(1).Single();
var isIpv4 = new byte[] { 0x11, 0x12 }.Contains(proxyv2IpvType);
var ipInBinary = isIpv4 ? request.BinaryRead(12) : request.BinaryRead(36);
var ip = Convert.ToString(ipInBinary);
var headers = request.Headers;
var hdr = headers.GetType();
var ro = hdr.GetProperty("IsReadOnly",
BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.IgnoreCase | BindingFlags.FlattenHierarchy);
ro.SetValue(headers, false, null);
hdr.InvokeMember("InvalidateCachedArrays",
BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Instance,
null, headers, null);
hdr.InvokeMember("BaseAdd",
BindingFlags.InvokeMethod | BindingFlags.NonPublic | BindingFlags.Instance,
null, headers,
new object[] { "X-Forwarded-For", new ArrayList { ip } });
ro.SetValue(headers, true, null);
}
}
}
测试结果会像
[TestClass]
public class XForwardedForRewriterTests {
[TestMethod]
public void Request_Should_Abort() {
//Arrange
var request = Mock.Of<HttpRequestBase>();
var sut = new XForwardedForRewriter();
//replace with mock request for test
sut.GetRequest = (object sender) => request;
//Act
sut.Context_BeginRequest(new object(), EventArgs.Empty);
//Assert
var mockRequest = Mock.Get(request);
mockRequest.Verify(m => m.Abort(), Times.AtLeastOnce);
}
[TestMethod]
public void Request_Should_Forward() {
//Arrange
var request = Mock.Of<HttpRequestBase>();
var mockRequest = Mock.Get(request);
//setup mocked request with desired behavior for test
var proxyv2HeaderStartRequence = new byte[12] { 0x0D, 0x0A, 0x0D, 0x0A, 0x00, 0x0D, 0x0A, 0x51, 0x55, 0x49, 0x54, 0x0A };
mockRequest
.Setup(m => m.BinaryRead(12))
.Returns(proxyv2HeaderStartRequence);
var fakeProxyv2IpvType = new byte[5] { 0x00, 0x12, 0x00, 0x00, 0x00 };
mockRequest
.Setup(m => m.BinaryRead(5))
.Returns(fakeProxyv2IpvType);
var headers = new NameValueCollection();
mockRequest.Setup(m => m.Headers).Returns(headers);
var sut = new XForwardedForRewriter();
//replace with mock request for test
sut.GetRequest = (object sender) => request;
//Act
sut.Context_BeginRequest(new object(), EventArgs.Empty);
//Assert
//...check request headers
var xForwardedFor = headers["X-Forwarded-For"];
Assert.IsNotNull(xForwardedFor);
}
}
苏特的一项观察是,ip
决心"System.Byte[]"
我认为这不是预期的行为。重新检查proxyv2HeaderStartRequence
.
除了添加访问请求的工厂方法外,其余测试代码保持不变。观察实际的实现,请求是如何包装在HttpRequestBase
派生类允许将模拟交换到其位置以进行测试。
现在应该允许在模块中应用 TDD。