I think some of those extensions rely on drastically different language primitives absent from most other languages. eg. https://github.com/rust-analyzer/rust

I think some of those extensions rely on drastically different language primitives absent from most other languages. eg. https://github.com/rust-analyzer/rust-analyzer/blob/master/docs/dev/lsp-extensions.md#related-tests https://github.com/rust-analyzer/rust-analyzer/blob/master/d... Rust has a built-in macro marker for tests. I suspect rust-analyzer uses this fact when it searches all AST nodes with the #[test] marker that contain a call to the symbol in question for the implementation. So adding the related tests interface to other languages would require similar AST-level primitives.