Before You File a Proposal Please Confirm You Have Done The Following...

• I havesearched for related issues and found none that match my proposal.
• I have searched thecurrent rule list and found no rules that match my proposal.
• I haveread the FAQ and my problem is not listed.

My proposal is suitable for this project

• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Link to the rule's documentation

https://typescript-eslint.io/rules/no-unnecessary-condition/

Description

Let's say:

functionfoo():string|undefined{// bla bla bla}constbar=foo();if(typeofbar==='string'){// It's ok// bla bla bla}

One day, I refactored thefoo function to return string only:

functionfoo():string{// bla bla bla}constbar=foo();if(typeofbar==='string'){// Smelly code. bar is always string. But no-unnecessary-condition does not report it// bla bla bla}

Fail

conststr:string='foo';if(typeofstr==='string'){// bla bla bla}

Pass

conststr:string|undefined='foo';if(typeofstr==='string'){// bla bla bla}

Additional Info

No response