[typescript] How to use `@ts-ignore` for a block

The // @ts-ignore comment enables the Typescript compiler to ignore the line below it.

How can one ignore a whole block of code with Typescript?

If you don't need typesafe, just bring block to a new separated file and change the extension to .js,.jsx

You can't.

As a workaround you can use a // @ts-nocheck comment at the top of a file to disable type-checking for that file: https://devblogs.microsoft.com/typescript/announcing-typescript-3-7-beta/

So to disable checking for a block (function, class, etc.), you can move it into its own file, then use the comment/flag above. (This isn't as flexible as block-based disabling of course, but it's the best option available at the moment.)