I created a VSCode extension recently (awalsh128/vscode-keep-sorted) and learned a lot of lessons trying to set up the test environment. What I wanted was:
Tests that run against a real VSCode instance, not mocks. An immutable test workspace, so every test starts from the same files. A log file per test, so I can see what the extension did when a test fails. Principles # Some things I learned the hard way about testing extensions.
VSCode Keep Sorted Extension Note Updated October 2026 for version 1.0.2. This post originally announced the 0.0.1 release in December 2025. Commands, settings, and features below reflect the latest version.
If you have experience in the software engineering field, an interview process can test the experience you have; projects, production scenarios, designs. Unfortunately, for junior positions and those out of college, there isn’t much to test for. Since most are computer scientists, you could test knowledge of algorithms and data structures but does that really prove the ability of a candidate? Knowing the upper bound complexity of an algorithm’s runtime is important but what about when a constant multiplying factor means the difference between production being up and down. We don’t have a solution for the Traveling Salesman Problem but we have very good and practical approximations (e.g. flight scheduling).
Flashback # The last time I used Unix-to-Unix format (AKA UUEncoding) was when USENET was still the big thing and Mosaic web browser was just coming out. That was until recently, when I had a requirement to encode and decode this file type.
I was recently putting some PowerShell scripts together for deployment and maintenance of software to our machine instances. One of the requirements was to be able to discover the service name from a Windows Service executable that uses ServiceInstaller. I needed to be able to extract this value in a generic way in order to query the service and stop it if running. Here is what I was able to put together.
Motivation # I had these flyweights that added a lot of overhead to the serialization process. They weren't really needed in the serialized payload either. In fact, I could recreate the flyweight in memory from just a single property on the object.
Motivation # I decided to use log4net for a recent project I had been working on. There is a concept of loggers and appenders. Loggers are composed of appenders and a log threshold. Appenders are consumers of logging information and provide specific implementations (eg. file, email, event log, database). You can configure the loggers and appenders either in the application configuration or at runtime.
Pitfalls in Production # Being able to monitor production services for potential errors is critical. Especially if the services are dependant on external resources which may become unavailable or exhibit unexpected behavior. Even if you follow good software development discipline, this is always a source of concern. Think network outages, unannounced third party API changes, hosted services becoming unavailable, etc.
The Creeping Problem # I recently found myself developing a request-response style system, where the lifetime of a request could be interrupted at any moment. For most same process execution, like your average desktop application, this is a concern, but arises more often when dealing with multiple coordinated processes. My case ended up being the latter.
