hemx/work/northstars/NS-0002-lsp-editor-experience.md

id, type, status, title, refs

id	type	status	title	refs
NS-0002	northstar	ready	LSP and editor experience completion	REQUIREMENTS.md docs/editor-support.md docs/diagnostics.md docs/hemplate-syntax.md hemx-lsp/src/main.rs hemx-build/src/lib.rs

Objective

Complete the .heml editor experience around existing compiler/build authority: diagnostics parity, completion, hover, cross-file facts, and correct LSP protocol behavior without inventing a second template language or editor framework.

Authority

• docs/editor-support.md says .heml authoring should feel like HTML first and layer hemx diagnostics/completions/hover on top.
• docs/hemplate-syntax.md is the stable syntax surface; LSP must not invent Vue/Handlebars-like syntax.
• docs/diagnostics.md keeps editor overlays subordinate to compiler/build diagnostics.
• REQUIREMENTS.md diagnostics/004 through diagnostics/008 and check/001/check/003 constrain editor overlays, spans, completion, hover, and build-visible validation.
• hemx-lsp/src/main.rs currently owns the CLI/LSP implementation surface.

Close when

• Diagnostics parity slices prove LSP-published diagnostics match hemx-build CLI diagnostics for open/save/file paths.
• Completion slices cover hemplate directives, data-hemx-* attributes, and context-sensitive generated facts without requiring external editor state.
• Hover slices explain real hemplate syntax and hemx attributes from docs authority.
• Cross-file fact slices describe what must fail at cargo check and what can remain editor-only.
• LSP protocol slices cover initialize, sync, completion, hover, diagnostics clearing, and error responses with tests.

Verification

• workledger check
• workledger list
• Later implementation slices should prefer focused cargo test -p hemx-lsp/integration tests, then cargo check --workspace or cargo run -p hemx-xtask -- test when build integration changes.

Non-goals

• Do not build a custom editor framework, formatter, Rust type system, selector model, or second .heml parser.
• Do not make VS Code/Cursor/Neovim provider behavior the source of truth; provider glue stays downstream of LSP/build facts.
• Do not add external publishing/signing flows without explicit authority.

Evidence

• hemx-lsp/src/main.rs already exposes diagnostics, completion, and hover entry points.
• docs/editor-support.md and docs/diagnostics.md define the editor/build boundary.