Much of TypeScript’s flexibility comes from its support for generics. They’re great for building up reusable abstractions so that you can share the “how” across your codebase even as the “what” varies significantly. In this post, I’ll describe a limitation that recently got in my way, and how I worked around it.

Most applications with user accounts will need to do permission checking. Of course, it’s important to include all of the appropriate testing to ensure that only users with the correct permissions can perform certain actions. But what if we also had a way to explicitly tell anyone making calls to restricted functions that a particular […]

For the last few years, we’ve been using a universal TypeScript platform including TypeScript, GraphQL, React, and Express. Having TypeScript on both the client and the server (including command-line utilities and background worker processes) has transformed how we go about ensuring the quality of the software we build. When compared to other stacks we’ve used, […]

TypeScript 2.8 introduced the conditional type operator, which allows for building comprehensive and powerful types. One of the more useful ones I’ve found is a “disjoint” type, which ensures that there are no elements in common between two sets or objects. This could also be referred to as “mutual exclusion.”

TypeScript is a wonderful language for designing data-driven applications. The type system is suited to describe the many different shapes and transformations of data as it travels from one end of a system to another. As my team has gained more experience with TypeScript, we’ve developed some guidelines for creating typed modules that help the […]