hemx/work/slices/SLICE-0009-lsp-protocol-contract.md

id, type, status, parent, title, refs

id	type	status	parent	title	refs
SLICE-0009	slice	ready	NS-0002	Harden LSP protocol behavior	hemx-lsp/src/main.rs docs/editor-support.md REQUIREMENTS.md

Objective

Make hemx-lsp predictable as an LSP server: initialize capabilities, document sync, completion, hover, diagnostics, shutdown, and unknown request errors should have focused protocol tests.

Authority

hemx-lsp/src/main.rs implements the protocol loop; docs/editor-support.md names the editor-facing command surface.

Close when

• Tests cover initialize, didOpen, didChange, didSave, didClose, completion, hover, shutdown, and unknown requests.
• The tests assert JSON-RPC framing and response IDs, not just helper functions.
• The server keeps normal HTML/tree-sitter tooling assumptions and does not add editor-provider policy.

Verification

• cargo test -p hemx-lsp
• cargo run -p hemx-lsp -- help

Non-goals

• Do not add async runtime or background watchers unless protocol tests prove sync IO is insufficient.
• Do not publish editor extensions in this slice.

Evidence

The current LSP loop is small and testable through in-memory readers/writers.