WebException on HTTP request while debugging - c#

I have a ASP.NET project which involves sending HTTP requests via the Web-API Framework. The following exception is only raised when debugging:
The server committed a protocol violation. Section=ResponseStatusLine
The project runs perfectly if I "Start Without Debugging".
How should I resolve this exception?
Any help is appreciated!
Update
The problem seems related to the ASP.NET MVC Identity Framework.
To access other Web-API methods, the client application has to first POST a login request (The login request does not need to be secure yet, and so I am sending the username and password strings directly to the Web-API POST method). If I comment out the login request, no more exception is raised.
Below are the relevant code snippets:
The Post method:
UserManager<ApplicationUser> UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext()));
AccountAccess ac = new AccountAccess();
public async Task<HttpResponseMessage> Post()
{
string result = await Request.Content.ReadAsStringAsync();
LoginMessage msg = JsonConvert.DeserializeObject<LoginMessage>(result);
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
var user = UserManager.Find(msg.username, msg.password);
if (user == null)
return response;
if (user.Roles == null)
return response;
var role = from r in user.Roles where (r.RoleId == "1" || r.RoleId == "2") select r;
if (role.Count() == 0)
{
return response;
}
bool task = await ac.LoginAsync(msg.username, msg.password);
response.Content = new StringContent(task.ToString());
return response;
}
The Account Access class (simulating the default AccountController in MVC template):
public class AccountAccess
{
public static bool success = false;
public AccountAccess()
: this(new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext())))
{
}
public AccountAccess(UserManager<ApplicationUser> userManager)
{
UserManager = userManager;
}
public UserManager<ApplicationUser> UserManager { get; private set; }
public async Task<bool> LoginAsync(string username, string password)
{
var user = await UserManager.FindAsync(username, password);
if (user != null)
{
await SignInAsync(user, isPersistent: false);
return true;
}
else
{
return false;
}
}
~AccountAccess()
{
if (UserManager != null)
{
UserManager.Dispose();
UserManager = null;
}
}
private IAuthenticationManager AuthenticationManager
{
get
{
return HttpContext.Current.GetOwinContext().Authentication;
}
}
private async Task SignInAsync(ApplicationUser user, bool isPersistent)
{
AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
var identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ApplicationCookie);
AuthenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = isPersistent }, identity);
}
}
Below are the relevant code snippets:
In client application:
public static async Task<List<T>> getItemAsync<T>(string urlAction)
{
message = new HttpRequestMessage();
message.Method = HttpMethod.Get;
message.RequestUri = new Uri(urlBase + urlAction);
HttpResponseMessage response = await client.SendAsync(message);
string result = await response.Content.ReadAsStringAsync();
List<T> msgs = JsonConvert.DeserializeObject<List<T>>(result);
return msgs;
}
In Web-API controller:
public HttpResponseMessage Get(string id)
{
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
if (id == "ItemA")
{
List<ItemAMessage> msgs = new List<ItemAMessage>();
// some code...
response.Content = new StringContent(JsonConvert.SerializeObject(msgs));
}
else if (id == "ItemB")
{
List<ItemBMessage> msgs = new List<ItemBMessage>();
// some code...
response.Content = new StringContent(JsonConvert.SerializeObject(msgs));
}
return response;
}
Some observations I have:
I thought that I may need to send the request asynchronously (with the async-await syntax), but the exception still persists that way.
If I step through the code, the request does enter the HTTP method, but the code breaks at random line (Why?!) before returning the response, so I assume no response is being sent back.
I have tried the following solutions, as suggested in answers to similar questions, none of which works for me:
Setting useUnsafeHeaderParsing to true
Adding the header Keep-Alive: false
Changing the port setting of Skype (I don't have Skype, and port 80 and 443 are not occupied)
Additional information, in case they matter:
Mac OS running Windows 8.1 with VMware Fusion
Visual Studio 2013
.NET Framework 4.5
IIS Express Server
Update 2
The exception is resolved, but I am unsure of which modification did the trick. AFAIK, either one or both of the following fixed it:
I have a checkConnection() method, which basically sends a GET request and return true on success. I added await to the HttpClient.SendAsync() method and enforced async all the way up.
I retracted all code in the MainWindow constructor, except for the InitializeComponent() method, into the Window Initialized event handler.
Any idea?
Below are relevant code to the modifications illustrated above:
the checkConnectionAsync method:
public static async Task<bool> checkConnectionAsync()
{
message = new HttpRequestMessage();
message.Method = HttpMethod.Get;
message.RequestUri = new Uri(urlBase);
try
{
HttpResponseMessage response = await client.SendAsync(message);
return (response.IsSuccessStatusCode);
}
catch (AggregateException)
{
return false;
}
}
Window Initialized event handler (retracted from the MainWindow constructor):
private async void Window_Initialized(object sender, EventArgs e)
{
if (await checkConnectionAsync())
{
await loggingIn();
getItemA();
getItemB();
}
else
{
logMsg.Content = "Connection Lost. Restart GUI and try again.";
}
}
Update 3
Although this may be a little off-topic, I'd like to add a side note in case anyone else falls into this – I have been using the wrong authentication approach for Web-API to start with. The Web-API project template already has a built-in Identity framework, and I somehow "replaced" it with a rather simple yet broken approach...
This video is a nice tutorial to start with.
This article provides a more comprehensive explanation.

In the Client Application you are not awaiting task. Accessing Result without awaiting may cause unpredictable errors. If it only fails during Debug mode, I can't say for sure, but it certainly isn't the same program (extra checks added, optimizations generally not enabled). Regardless of when Debugging is active, if you have a code error, you should fix that and it should work in either modes.
So either make that function async and call the task with the await modifier, or call task.WaitAndUnwrapException() on the task so it will block synchronously until the result is returned from the server.

Make sure URL has ID query string with value either as Item A or Item B. Otherwise, you will be returning no content with Http status code 200 which could lead to protocol violation.

When you use SendAsync, you are required to provide all relevant message headers yourself, including message.Headers.Authorization = new AuthenticationHeaderValue("Basic", token); for example.
You might want to use GetAsync instead (and call a specific get method on the server).
Also, are you sure the exception is resolved? If you have some high level async method that returns a Task and not void, that exception might be silently ignored.

Related

HttpContent gets disposed between try and catch

I'm performing a simple GET request to a ASP.NET Core Web API, I created, within Xamarin.Forms 4.8. For this I'm using the following code:
public async Task<Result<bool>> GetSomeResult()
{
var client = service.Client;
HttpResponseMessage response = null;
try
{
response = await client.GetAsync(new UriHelper(endpoint, "someEndpoint")).ConfigureAwait(false);
response.EnsureSuccessStatusCode(); // will throw a exception on a non-success status code
return await response.Content.ReadAsAsync<bool>().ConfigureAwait(false);
}
catch (Exception ex)
{
if (response?.StatusCode == HttpStatusCode.InternalServerError)
{
// !!! The error occurs in the next line !!!
SomeErrorClass id = await response.Content.ReadAsAsync<SomeErrorClass>().ConfigureAwait(false);
return new Result<bool>(SomeErrorClass.ToString());
}
return new Result<bool>(ex);
}
}
The service is a singleton that's being injected into the constructor (via DryIoc) of the surrounding class. This service is a wrapper around a HttpClient instance and does nothing more than providing a facility to configure the HttpClient (as well as disposing and replacing the instance when its configuration has been chaned). So after configuration the same HttpClient instance will be returned whenever service.Client is used. The code is something like this:
public class ServiceConnection
{
private const string Localhost = "https://127.0.0.1";
private readonly PreferenceService preferences;
private readonly IHttpClientHandlerProvider handlerProvider;
public HttpClient Client { get; private set; }
public ServiceConnection(PreferenceService preferences, IHttpClientHandlerProvider handlerProvider)
{
this.preferences = preferences;
this.handlerProvider = handlerProvider;
Client = CreateClient();
}
private HttpClient CreateClient()
{
var handler = new TimeoutHandler()
{
DefaultTimeout = TimeSpan.FromSeconds(10),
InnerHandler = handlerProvider?.GetHandler(opt =>
{
opt.ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousAcceptAnyServerCertificateValidator;
opt.UseDefaultCredentials = true;
opt.AllowAutoRedirect = true;
})
};
Uri.TryCreate($"{preferences.Server ?? Localhost}/api/", UriKind.Absolute, out var baseAddress);
var client = new HttpClient(handler, true)
{
BaseAddress = baseAddress,
Timeout = TimeSpan.FromSeconds(20),
};
client.DefaultRequestHeaders.Add(CustomHttpHeaders.DeviceId, preferences.UUID);
return client;
}
public void RefreshConnection()
{
Client?.Dispose();
Client = CreateClient();
}
}
The problem is the line in which I try to read the HttpContent from the HttpResponseMessage. Whenever I call it I get a System.ObjectDisposedExceptionsaying 'Cannot access a disposed object.
Object name: 'System.Net.Http.StreamContent'.'.
I already tried setting the disposeHandler parameter of the HttpClient to true and false since I've seen some people on the internet suggesting that that'll fix the issue, but no luck for me so far.
The problem isn't disposal. There are two problems here, one causing the other:
Exceptions are used for flow control. Instead of throwing on failure, you could check the response's status code
Before .NET Core 3, EnsureStatusCode closes the stream.
The root cause is the use of exceptions for flow control.
This can be solved by fixing the first problem, which would also improve performance a lot. Throwing exceptions is expensive, several orders of magnitude more expensive than an if. As in 100-1000x times faster :
if (response.IsSuccessStatusCode)
{
var value=await response.Content.ReadAsAsync<bool>();
return value; //Should this be `new Result(value) ??
}
else if (response.StatusCode == HttpStatusCode.InternalServerError)
{
var id = await response.Content.ReadAsAsync<SomeErrorClass>();
return new Result<bool>(SomeErrorClass.ToString());
}
else
{
var reason=$"{response.StatusCode}:{response.ReasonPhrase}";
return new Result<bool>(reason);
}
Throwing would obfuscate the response phrase too, which would make troubleshooting a lot harder

How to test a controller POST method which returns no data in response content in .NET Core 3.1?

i am new to integration tests. I have a controller method which adds a user to the database, as shown below:
[HttpPost]
public async Task<IActionResult> CreateUserAsync([FromBody] CreateUserRequest request)
{
try
{
var command = new CreateUserCommand
{
Login = request.Login,
Password = request.Password,
FirstName = request.FirstName,
LastName = request.LastName,
MailAddress = request.MailAddress,
TokenOwnerInformation = User
};
await CommandBus.SendAsync(command);
return Ok();
}
catch (Exception e)
{
await HandleExceptionAsync(e);
return StatusCode(StatusCodes.Status500InternalServerError,
new {e.Message});
}
}
As you have noticed my method returns no information about the user which has been added to the database - it informs about the results of handling a certain request using the status codes. I have written an integration test to check is it working properly:
[Fact]
public async Task ShouldCreateUser()
{
// Arrange
var createUserRequest = new CreateUserRequest
{
Login = "testowyLogin",
Password = "testoweHaslo",
FirstName = "Aleksander",
LastName = "Kowalski",
MailAddress = "akowalski#onet.poczta.pl"
};
var serializedCreateUserRequest = SerializeObject(createUserRequest);
// Act
var response = await HttpClient.PostAsync(ApiRoutes.CreateUserAsyncRoute,
serializedCreateUserRequest);
// Assert
response
.StatusCode
.Should()
.Be(HttpStatusCode.OK);
}
I am not sure is it enough to assert just a status code of response returned from the server. I am confused because, i don't know, shall i attach to assert section code, which would get all the users and check does it contain created user for example. I don't even have any id of such a user because my application finds a new id for the user while adding him/her to the database. I also have no idea how to test methods like that:
[HttpGet("{userId:int}")]
public async Task<IActionResult> GetUserAsync([FromRoute] int userId)
{
try
{
var query = new GetUserQuery
{
UserId = userId,
TokenOwnerInformation = User
};
var user = await QueryBus
.SendAsync<GetUserQuery, UserDto>(query);
var result = user is null
? (IActionResult) NotFound(new
{
Message = (string) _stringLocalizer[UserConstants.UserNotFoundMessageKey]
})
: Ok(user);
return result;
}
catch (Exception e)
{
await HandleExceptionAsync(e);
return StatusCode(StatusCodes.Status500InternalServerError,
new {e.Message});
}
}
I believe i should somehow create a user firstly in Arrange section, get it's id and then use it in Act section with the GetUserAsync method called with the request sent by HttpClient. Again the same problem - no information about user is returned, after creation (by the way - it is not returned, because of my CQRS design in whole application - commands return no information). Could you please explain me how to write such a tests properly? Have i missed anything? Thanks for any help.
This is how I do it:
var response = (CreatedResult) await _controller.Post(createUserRequest);
response.StatusCode.Should().Be(StatusCodes.Status201Created);
The second line above is not necessary, just there for illustration.
Also, your response it's better when you return a 201 (Created) instead of the 200(OK) on Post verbs, like:
return Created($"api/users/{user.id}", user);
To test NotFound's:
var result = (NotFoundObjectResult) await _controller.Get(id);
result.StatusCode.Should().Be(StatusCodes.Status404NotFound);
The NotFoundObjectResult assumes you are returning something. If you are just responding with a 404 and no explanation, replace NotFoundObjectResult with a NotFoundResult.
And finally InternalServerErrors:
var result = (ObjectResult) await _controller.Get(id);
result.StatusCode.Should().Be(StatusCodes.Status500InternalServerError);
You can use integrationFixture for that using this NuGet package. This is an AutoFixture alternative for integration tests.
The documented examples use Get calls but you can do other calls too. Logically, you should test for the status code (OkObjectResult means 200) value and the response (which could be an empty string, that is no problem at all).
Here is the documented example for a normal Get call.
[Fact]
public async Task GetTest()
{
// arrange
using (var fixture = new Fixture<Startup>())
{
using (var mockServer = fixture.FreezeServer("Google"))
{
SetupStableServer(mockServer, "Response");
var controller = fixture.Create<SearchEngineController>();
// act
var response = await controller.GetNumberOfCharacters("Hoi");
// assert
var request = mockServer.LogEntries.Select(a => a.RequestMessage).Single();
Assert.Contains("Hoi", request.RawQuery);
Assert.Equal(8, ((OkObjectResult)response.Result).Value);
}
}
}
private void SetupStableServer(FluentMockServer fluentMockServer, string response)
{
fluentMockServer.Given(Request.Create().UsingGet())
.RespondWith(Response.Create().WithBody(response, encoding: Encoding.UTF8)
.WithStatusCode(HttpStatusCode.OK));
}
In the example above, the controller is resolved using the DI described in your Startup class.
You can also do an actual REST call using using Refit. The application is self hosted inside your test.
using (var fixture = new RefitFixture<Startup, ISearchEngine>(RestService.For<ISearchEngine>))
{
using (var mockServer = fixture.FreezeServer("Google"))
{
SetupStableServer(mockServer, "Response");
var refitClient = fixture.GetRefitClient();
var response = await refitClient.GetNumberOfCharacters("Hoi");
await response.EnsureSuccessStatusCodeAsync();
var request = mockServer.LogEntries.Select(a => a.RequestMessage).Single();
Assert.Contains("Hoi", request.RawQuery);
}
}

Something went wrong, please try again from BotFramework MessagingExtesion

I've been working on implementing a bot for MS Teams connecting to our application, using the BotFramework v4, and C# (Web API library). I've registered the bot in azure and have successfully gotten the chat portion of the bot working correctly.
However, when I go to search for items from the messaging extension I get the above error of Something went wrong. Please try again. I have stepped through the code and from the server side code it appears I am returning the correct responses, however when I inspect the request from the Teams web client, the response is empty.
From the Bot side of the code, I have it implemented as follows
protected override async Task<MessagingExtensionResponse> OnTeamsMessagingExtensionQueryAsync(ITurnContext<IInvokeActivity> turnContext, MessagingExtensionQuery query, CancellationToken cancellationToken)
{
var text = query?.Parameters?[0]?.Value as string ?? string.Empty;
if (text == "true" && query?.Parameters?[0]?.Name == "initialRun")
return new MessagingExtensionResponse { ComposeExtension = new MessagingExtensionResult { Type = "message", Text = "Please enter your search term above" } };
else
return new MessagingExtensionResponse { ComposeExtension = new MessagingExtensionResult { Type = "message", Text = "Not the initial run" } };
}
and the Controller
public BotController(IBotFrameworkHttpAdapter adapter, IBot bot)
{
_adapter = adapter;
_bot = bot;
}
public async Task Messages()
{
await _adapter.ProcessAsync(ActionContext.Request, ActionContext.Request.CreateResponse(), _bot);
}
Can anyone point me in the right direction as to where I'm going wrong?
For anyone else running into the same problem, if you are dealing with the BotFramework from ASP.NET WebApi, you need to make sure you are returning the response correctly from the messages endpoint.
i.e. The following routine in the controller
public async Task Messages()
{
await _adapter.ProcessAsync(ActionContext.Request, ActionContext.Request.CreateResponse(), _bot);
}
needs to turn into
public async Task<HttpResponseMessage> Messages()
{
var response = new HttpResponseMessage();
await _adapter.ProcessAsync(ActionContext.Request, response, _bot);
return response;
}

Blazor Request blocked by CORS policy on PHP API

I am setting up a PHP API and a web-page based on client-side Blazor. But for some reason CORS is triggered and my login process or any requests to my PHP pages result in CORS errors.
I started out testing my PHP API with a C# console app and the Blazor app, I tried using without any database access to test the functionality. The Blazor is right now running with Preview 9. The PHP version is 5.3.8. I could in theory update it, but several other active projects are running on it and I do not have any test environment. MySQL version 5.5.24.
First I figured it might have been because I was running it on my local machine, so I pushed it to the website where the PHP and MySQL is also running. Still I run into this CORS error.
I am still just testing this, so I have tried setting it to allow any origin. I have not had any experience with CORS before this. Pretty sure I ought to be able to add PHP code in each file I access that should allow CORS, but since it should all be on the same website, I figure CORS should not even be relevant?
PHP Code:
function cors() {
// Allow from any origin
if (isset($_SERVER['HTTP_ORIGIN'])) {
// Decide if the origin in $_SERVER['HTTP_ORIGIN'] is one
// you want to allow, and if so:
header("Access-Control-Allow-Origin: {$_SERVER['HTTP_ORIGIN']}");
header('Access-Control-Allow-Credentials: true');
header('Access-Control-Max-Age: 86400'); // cache for 1 day
}
// Access-Control headers are received during OPTIONS requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_METHOD']))
// may also be using PUT, PATCH, HEAD etc
header("Access-Control-Allow-Methods: GET, POST, OPTIONS");
if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']))
header("Access-Control-Allow-Headers: {$_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']}");
exit(0);
}
echo "You have CORS!";
}
cors();
C# code using the injected HttpClient:
var resp = await Http.GetStringAsync(link);
The error I get is:
Access to fetch at 'https://titsam.dk/ntbusit/busitapi/requestLoginToken.php' from origin 'https://www.titsam.dk' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
The response I hoped to get was that the link I use return a token for the login as it does for my API.
Is it because its running client side maybe and this triggers CORS? But that does not seem to explain why I cannot make it allow all.
Update:
My C# code in OnInitializedAsync:
link = API_RequestLoginTokenEndPoint;
Http.DefaultRequestHeaders.Add("User-Agent", "HttpClientFactory-Sample");
Http.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Authorization", "basic:testuser:testpass");
var requestMessage = new HttpRequestMessage(HttpMethod.Get, link);
requestMessage.Properties[WebAssemblyHttpMessageHandler.FetchArgs] = new
{
credentials = "include"
};
var response = await Http.SendAsync(requestMessage);
var responseStatusCode = response.StatusCode;
var responseBody = await response.Content.ReadAsStringAsync();
output = responseBody + " " + responseStatusCode;
Update 2:
It finally works. The C# code I linked is the solution Agua From Mars suggested and it solved the problem to use SendAsync with a HttpRequestMessage and adding the Fetch property include credentials to it. Another alternative was to add this line to the startup:
WebAssemblyHttpMessageHandler.DefaultCredentials = FetchCredentialsOption.Include;
Then I could keep doing what I did to begin with, using GetStringAsync as it becomes the default.
await Http.GetStringAsync(API_RequestLoginTokenEndPoint);
So all the solutions Agua From Mars suggested worked. But I encountered a browser problem, where it kept the CORS issue in the cache somehow even after it had gotten solved, so it seemed like nothing had changed. Some code changes would show a different result, but I guess the CORS part was kept alive. With Chrome it helped opening a new pane or window. In my Opera browser this was not enough, I had to close all panes with the site open to ensure it would clear the cache and then opening a new window or pane with the site works in Opera as well. I had already in both browsers trying to use ctrl-F5 and Shift-F5 to get them to clear the cache. This did not change anything.
I hope this will help others avoid spending 2-3 days on an issue like this.
update 3.1-preview3
In 3.1-preview3, we cannot use the fetch option per message, the options is global
WebAssemblyHttpMessageHandlerOptions.DefaultCredentials = FetchCredentialsOption.Include;
WebAssemblyHttpMessageHandler has been removed. The HttpMessageHanlder used is WebAssembly.Net.Http.HttpClient.WasmHttpMessageHandler from WebAssembly.Net.Http but don't include WebAssembly.Net.Http in your depencies or the application will failled to launch.
If you want to use the HttpClientFactory you can implement like that :
public class CustomDelegationHandler : DelegatingHandler
{
private readonly IUserStore _userStore;
private readonly HttpMessageHandler _innerHanler;
private readonly MethodInfo _method;
public CustomDelegationHandler(IUserStore userStore, HttpMessageHandler innerHanler)
{
_userStore = userStore ?? throw new ArgumentNullException(nameof(userStore));
_innerHanler = innerHanler ?? throw new ArgumentNullException(nameof(innerHanler));
var type = innerHanler.GetType();
_method = type.GetMethod("SendAsync", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.InvokeMethod) ?? throw new InvalidOperationException("Cannot get SendAsync method");
WebAssemblyHttpMessageHandlerOptions.DefaultCredentials = FetchCredentialsOption.Include;
}
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
request.Headers.Authorization = new AuthenticationHeaderValue(_userStore.AuthenticationScheme, _userStore.AccessToken);
return _method.Invoke(_innerHanler, new object[] { request, cancellationToken }) as Task<HttpResponseMessage>;
}
}
public void ConfigureServices(IServiceCollection services)
{
services.AddTransient(p =>
{
var wasmHttpMessageHandlerType = Assembly.Load("WebAssembly.Net.Http")
.GetType("WebAssembly.Net.Http.HttpClient.WasmHttpMessageHandler");
var constructor = wasmHttpMessageHandlerType.GetConstructor(Array.Empty<Type>());
return constructor.Invoke(Array.Empty<object>()) as HttpMessageHandler;
})
.AddTransient<CustomDelegationHandler>()
.AddHttpClient("MyApiHttpClientName")
.AddHttpMessageHandler<CustonDelegationHandler>();
}
3.0 -> 3.1-preview2
On Blazor client side your need to tell to the Fetch API to send credentials (cookies and authorization header).
It's describe in the Blazor doc Cross-origin resource sharing (CORS)
requestMessage.Properties[WebAssemblyHttpMessageHandler.FetchArgs] = new
{
credentials = FetchCredentialsOption.Include
};
ex:
#using System.Net.Http
#using System.Net.Http.Headers
#inject HttpClient Http
#code {
private async Task PostRequest()
{
Http.DefaultRequestHeaders.Authorization =
new AuthenticationHeaderValue("Bearer", "{OAUTH TOKEN}");
var requestMessage = new HttpRequestMessage()
{
Method = new HttpMethod("POST"),
RequestUri = new Uri("https://localhost:10000/api/TodoItems"),
Content =
new StringContent(
#"{""name"":""A New Todo Item"",""isComplete"":false}")
};
requestMessage.Content.Headers.ContentType =
new System.Net.Http.Headers.MediaTypeHeaderValue(
"application/json");
requestMessage.Content.Headers.TryAddWithoutValidation(
"x-custom-header", "value");
requestMessage.Properties[WebAssemblyHttpMessageHandler.FetchArgs] = new
{
credentials = FetchCredentialsOption.Include
};
var response = await Http.SendAsync(requestMessage);
var responseStatusCode = response.StatusCode;
var responseBody = await response.Content.ReadAsStringAsync();
}
}
You can set up this option globaly with WebAssemblyHttpMessageHandlerOptions.DefaultCredentials static proprerty.
Or you can implement a DelegatingHandler and set it up in DI with the HttpClientFactory:
public class CustomWebAssemblyHttpMessageHandler : WebAssemblyHttpMessageHandler
{
internal new Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
return base.SendAsync(request, cancellationToken);
}
}
public class CustomDelegationHandler : DelegatingHandler
{
private readonly CustomWebAssemblyHttpMessageHandler _innerHandler;
public CustomDelegationHandler(CustomWebAssemblyHttpMessageHandler innerHandler)
{
_innerHandler = innerHandler ?? throw new ArgumentNullException(nameof(innerHandler));
}
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
request.Properties[WebAssemblyHttpMessageHandler.FetchArgs] = new
{
credentials = "include"
};
return _innerHandler.SendAsync(request, cancellationToken);
}
}
In Setup.ConfigureServices
services.AddTransient<CustomWebAssemblyHttpMessageHandler>()
.AddTransient<WebAssemblyHttpMessageHandler>()
.AddTransient<CustomDelegationHandler>()
.AddHttpClient(httpClientName)
.AddHttpMessageHandler<CustomDelegationHandler>();
Then you can create an HttpClient for your API with IHttpClientFactory.CreateClient(httpClientName)
To use the IHttpClientFactory you need to install Microsoft.Extensions.Http package.
3.0-preview3 => 3.0-preview9
Replace WebAssemblyHttpMessageHandler with BlazorHttpMessageHandler

Async Web Api Action Returning Prematurely

I am writing a nuget package that will consume a REST API I wrote. Im having some difficulty in calling it asynchronously using RestSharp.
I have the following controller method:
[HttpGet("{id}")]
public async Task<IActionResult> GetFeatureByIdAsync(string id)
{
if (string.IsNullOrWhiteSpace(id))
{
ModelState.AddModelError("id-Null", "The id parameter cannot be null.");
return BadRequest(ModelState);
}
var feature = await _director.GetFeatureById(id);
if (feature == null)
return NotFound();
var model = new ViewModel<Feature>(feature);
return Ok(model);
}
I have the follow class library in a seperate solution:
public async Task<bool> IsSwitchEnabledAsync(string name)
{
string fullyFormedUrl = $"{_url}/{name}";
var client = new RestClient(fullyFormedUrl) { Encoding = Encoding.UTF8 };
var request = new RestRequest(Method.GET) { RequestFormat = DataFormat.Json };
var result = await client.ExecuteTaskAsync<FeatureViewModel>(request);
var message = $"Response: {result.StatusCode}, {result.ResponseStatus}, " +
$"\n\nError: {result.ErrorException}, {result.ErrorMessage} " +
$"\n\nData: {result.Content}";
Debug.WriteLine(message);
return result.Data != null;
}
I have the following basic integration test sandbox:
[TestFixture]
public class Sandbox
{
private FeatureSwitch _sut;
[OneTimeSetUp]
public void Setup()
{
const string machineName = "localhost";
const int port = 5000;
_sut = new FeatureSwitch(machineName, port);
}
[Test]
public async Task ShouldReturnTrue()
{
var result = await _sut.IsSwitchEnabledAsync("Release_US501_AddUser");
result.Should().BeTrue();
}
}
I am looking for a little education on the best approach on how to call the API correctly? As my sandbox code is failing with an Internal Server 500 Error. This is because the api method is waiting for the nested async call to complete. So the initial request returns back to the sandbox code before the nested api call has a chance to complete.
The sandbox test code needs to wait for the API to return a result. At the moment it is not doing this.
So what is the correct approach here?
UPDATE: My issue was down to incorrect usage of a Mongo library method.
My issue came from a .chained method call on a Mongo library method:
I was trying to do the following:
Collection.Find(x => x.Name.ToLower().Equals(name.ToLower())
The code compiled but it was throwing an exception that VS studio 17 was not breaking on so i had no idea where the issue was occurring. With code lens turned on, I noticed that the failed requests highlighted in red. This opened an App Insights window which highlighted a break down of 4 InvalidOperationException() that had been thrown. That's how i discovered what the Internal Server Error 500 was about.
Anyways that's how i solved Async Web API problem - it was my first time using it on a web service so I had no idea what the expected default behaviour ought to be.

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