Use `//@ts-check` in Visual Studio Code to Find Undeclared Variables (and save yourself hours of hunting)

Posted on | by Jason Snelders

Oh. My. God!

I just discovered //@ts-check in Visual Studio Code.

For all the web/JavaScript developers out there, add that comment to the top of your .js file in Visual Studio Code (that’s all you have to do).

Now, any issues in you variables (like using variables you haven’t declared) will show as an error in the IDE.

This is what I call super charging your IDE and your development.

I could have saved myself half a day’s work yesterday if I’d thought to search for “visual studio code undeclared javascript variables” beforehand. ?‍♂️

See: https://code.visualstudio.com/docs/nodejs/working-with-javascript#_type-checking-javascript