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/prefer-nullish-coalescing/

Description

I propose that the rule should flagif statements that are equivalent to a nullish coalescing assignment (??=).

Fail

declareletfoo:{a:string}|null;declarefunctionmakeFoo():{a:string};functionlazyInitializeByTruthiness(){if(!foo){foo=makeFoo();}}functionlazyInitializeByNullCheck(){if(foo==null){foo=makeFoo();}}export{}

Pass

declareletfoo:{a:string}|null;declarefunctionmakeFoo():{a:string};functionlazyInitializeByNullishCoalescingAssignment(){foo??=makeFoo();}export{}

Additional Info

playground

relates to#6309