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

• My proposal specifically checks TypeScript syntax, or it proposes a check that requires type information to be accurate.
• My proposal is not a "formatting rule"; meaning it does not just enforce how code is formatted (whitespace, brace placement, etc).
• I believe my proposal would be useful to the broader TypeScript community (meaning it is not a niche proposal).

Description

I've seen people doing the interface into class declaration merging pattern a few times (like in#5273) and I don't think people understand how unsafe it can be.

I propose a lint rule which detects instances of unsafe declaration merging and warns against it.

Fail Cases

interfaceFoo{}classFoo{}

Pass Cases

interfaceFoo{}classBarimplementsFoo{}namespaceFoo2{}namespaceFoo2{}enumFoo2{}namespaceFoo3{}functionFoo3(){}

Additional Info

No response