C# – Switch from using HttpWebRequest to HttpClient

There are many reasons to use HttpClient instead of HttpWebRequest. For one, the MSDN docs strongly recommends against using HttpWebRequest, and using HttpClient instead. That should be enough, but if you need a little more convincing, take a look at the Practical reasons to not use HttpWebRequest section below. In addition to explaining why not … Read more

How to use toxiproxy to verify your code can handle timeouts and unavailable endpoints

When you have code that calls an endpoint, you need to make sure it’s resilient and can handle error scenarios, such as timeouts. One way to prove your code is resilient is by using toxiproxy to simulate bad behavior. Toxiproxy sits between your client code and the endpoint. It receives requests from your client, applies … Read more

Event-driven .NET: How to consume an SSE endpoint with HttpClient

Server-Sent Events (SSE) allow a client to subscribe to messages from the server. It creates a one-way stream from the server to the client. When the server has new messages for the client, it writes them to the stream. This is an alternative to the client polling the server for updates. Use the following to … Read more

C# – How to unit test code that uses HttpClient

HttpClient is a dependency. Like any other dependency, you need to pass it into your code (aka dependency injection). By passing it in, you can mock it out in unit tests. There are two approaches to mocking it out: Wrap the HttpClient and mock out the wrapper. Use a real HttpClient with a mocked out … Read more

C# – How to make concurrent requests with HttpClient

The HttpClient class was designed to be used concurrently. It’s thread-safe and can handle multiple requests. You can fire off multiple requests from the same thread and await all of the responses, or fire off requests from multiple threads. No matter what the scenario, HttpClient was built to handle concurrent requests. To use HttpClient effectively … Read more

Fixing the Sync over Async antipattern

The Sync over Async antipattern is when you’re using a blocking wait on an async method, instead of awaiting the results asynchronously. This wastes the thread, causes unresponsiveness (if called from the UI), and exposes you to potential deadlocks. There are two causes: Calling Wait() on the Task returned by the async call. Using Task.Result. … Read more