TSInterfaceDeclaration: implements

Is this correct? I see in the typescript-eslint/parser AST that interface A implements B {} seems to be valid, but that shouldn't be valid in TypeScript code.

The original issue originated from my eslint rule failing for this TypeScript compiler test case.
So I thought it is valid TypeScript.

seems to be valid, but that shouldn't be valid in TypeScript code.

TS reuses parsing logic in a few places to deduplicate - for example class declarations and interface declarations are remarkably similar.

Which means that TS can sometimes do weird things. Add to that the no-error "recovery" nature of the parser and you will find that it parses a lot of invalid code successfully and produces an AST.

In this instance here I'd assume this is a legacy thing combined with a shared parser logic thing. The parser allows you to write an interface with implements, and for some reason it also encodes that in the AST.
When our conversion logic was imemented - whoever did it just ensured all valid child props were converted without deciding it it made sense syntactically.

Which leads us into this weird state where we produce an AST for obviously incorrect code.