Writing a GitHub Webhook as an Azure Function

I recently experimented with Azure Functions and GitHub apps, and I wanted to share what I learned. A bit of background As you may already know, I'm one of the maintainers of the FakeItEasy mocking library. As is common in open-source projects, we use a workflow based on feature branches and pull requests. When a change is requested in a PR during code review, we usually make the change as a fixup commit, because it makes it easier to review, and because we like to keep a clean history.

Understanding the ASP.NET Core middleware pipeline

Middlewhat? The ASP.NET Core architecture features a system of middleware, which are pieces of code that handle requests and responses. Middleware are chained to each other to form a pipeline. Incoming requests are passed through the pipeline, where each middleware has a chance to do something with them before passing them to the next middleware. Outgoing responses are also passed through the pipeline, in reverse order. If this sounds very abstract, the following schema from the official ASP.

Cleanup Git history to remove unwanted files

I recently had to work with a Git repository whose modifications needed to be ported to another repo. Unfortunately, the repo had been created without a .gitignore file, so a lot of useless files (bin/obj/packages directories…) had been commited. This made the history hard to follow, because each commit had hundreds of modified files. Fortunately, it's rather easy with Git to cleanup a branch, by recreating the same commits without the files that shouldn't have been there in the first place.

Better timeout handling with HttpClient

The problem If you often use HttpClient to call REST APIs or to transfer files, you may have been annoyed by the way this class handles request timeout. There are two major issues with timeout handling in HttpClient: The timeout is defined at the HttpClient level and applies to all requests made with this HttpClient; it would be more convenient to be able to specify a timeout individually for each request.

Transform T4 templates as part of the build, and pass variables from the project

T4 (Text Template Transformation Toolkit) is a great tool to generate code at design time; you can, for instance, create POCO classes from database tables, generate repetitive code, etc. In Visual Studio, T4 files (.tt extension) are associated with the TextTemplatingFileGenerator custom tool, which transforms the template to generate an output file every time you save the template. But sometimes it's not enough, and you want to ensure that the template's output is regenerated before build.

Common MSBuild properties and items with Directory.Build.props

To be honest, I never really liked MSBuild until recently. The project files generated by Visual Studio were a mess, most of their content was redundant, you had to unload the projects to edit them, it was poorly documented… But with the advent of .NET Core and the new “SDK-style” projects, it's become much, much better. MSBuild 15 introduced a pretty cool feature: implicit imports (I don't know if it's the official name, but I'll use it anyway).

Testing and debugging library code from LINQPad

I've been meaning to blog about LINQPad in a very long time. In case you don't know about it, LINQPad is a tool that lets you write and test code very quickly without having to create a full-blown project in Visual Studio. It supports C#, VB.NET, F# and SQL. It was initially intended as an educational tool to experiment with LINQ (its author, Joe Albahari, developed it as companion to his C# in a Nutshell book), but it's also extremely useful as a general-purpose .

Linq performance improvements in .NET Core

By now, you're probably aware that Microsoft released an open-source and cross-platform version of the .NET platform: .NET Core. This means you can now build and run .NET apps on Linux or macOS. This is pretty cool in itself, but it doesn't end there: .NET Core also brings a lot of improvements to the Base Class Library. For instance, Linq has been made faster in .NET Core. I made a little benchmark to compare the performance of some common Linq methods, and the results are quite impressive:

Easy text parsing in C# with Sprache

A few days ago, I discovered a little gem: Sprache. The name means “language” in German. It's a very elegant and easy to use library to create text parsers, using parser combinators, which are a very common technique in functional programming. The theorical concept may seem a bit scary, but as you'll see in a minute, Sprache makes it very simple. Text parsing Parsing text is a common task, but it can be tedious and error-prone.

What's new in FakeItEasy 3.0.0?

FakeItEasy is a popular mocking framework for .NET, with an very intuitive and easy-to-use API. For about one year, I've been a maintainer of FakeItEasy, along with Adam Ralph and Blair Conrad. It's been a real pleasure working with them and I had a lot of fun! Today I'm glad to announce that we're releasing FakeItEasy 3.0.0, which supports .NET Core and introduces a few useful features. Let's see what's new!