Prevent deleting dead code during Auto Format on Save?

Question

What is the magic configuration for allowing a file to be auto-formatted upon a Save operation, but stop / disable / prevent VSCode from deleting dead code?

Sometimes I want to deliberately throw an exception in the middle of a function, for debugging purposes but am forced to comment out all following code in order not to get it deleted.

What's worse is that sometime I save while the editor didn't yet recover from some error in the code, thinks the code still contains an error, and causes code deletions which should not happen in the first place. I found myself too many times pulling up git in order to restore good code which was wrongly deleted.

Is there a clear "do not delete dead code" option to switch on?

UPDATE:

1. Running Prettier (the file's formatter) from command line did not delete dead code.
2. Trying to disable all extensions didn't help either. The dead code is still deleted upon save.

Answer 1

source.fixAll activates also TS fixes, which are somehow too aggressive to use on save. Only enabling eslint fixes with source.fixAll.eslint is a good compromise - it will still report dead code (no-unreachable) but not delete it.

https://github.com/microsoft/vscode/issues/109530