Over on the Divilly Sausages blog they released a pretty comprehensive guide on setting up Phaser, TypeScript, and Visual Studio Code:

"While you could write pure JS, much in the same way as you could eat your dinner by having someone throw it at your face from across the room, a more sensible approach is to using something like TypeScript, a Microsoft-developed superset of JavaScript that compiles down to pure JS. The syntax is extremely familar if you're coming from something like ActionScript, so while it has some flaws, it's a great choice.

Added to that, Microsoft have also released Visual Studio Code, a free, cross-platform IDE, specifically geared towards ASP.NET and NodeJS. Visual Studio Code also supports TypeScript, and did I mention that it's free?

It's still under heavy development, but if there's one thing Microsoft do well, it's developer tools.

I didn't see much info on getting all these to play nice, so this is a quick step-by-step guide on getting a development environment up and running."

Read more here