Since Deno supports the V8 Inspector Protocol, it is a fairly easy task
to launch a debugging session in Webstorm.

1 - First, create a Debug configuration (Attach to Node.js/Chrome)

2 - Now, run your local Deno script (here server.ts)

$ deno run --inspect --allow-net server.ts

3 - Add a breakpoint and start debugging

Enjoy your debugging session!

For more information: https://deno.land/manual/tools/debugger#chrome-devtools