TypeScript 4.0 Announced

TypeScript 4.0 has been released and is available for the Insiders version of Visual Studio Code, Visual Studio 2017, or Visual Studio 2019.

Here’s a punch list of what’s new:

• Variadic Tuple Types
• Labeled Tuple Elements
• Class Property Inference from Constructors
• Short-Circuiting Assignment Operators
• unknown on catch Clauses
• Custom JSX Factories
• Speed Improvements in build mode with --noEmitOnError
• --incremental with --noEmit

One of the big concerns with TypeScript 4 was if there would be major breaking changes. As of now, it does not appear there will be.

To get started, install by running the following:

npm install -D typescript