Writing .d.ts Files

Those of us who have been doing TypeScript for a while will know that feeling when you first realise that you may have wrote a lot of TypeScript in a .ts file - but you find yourself having to start looking things up again when you are in a .d.ts file.

There are a lot of similarities between a .ts file, but the rules are often subtly different in a .d.ts files and having a place where you can share and debug .d.ts files becomes extremely useful then.

The .d.ts mode can be turned on by changing the language to “TypeScript Definition” inside the “TS Config” panel.