fix(lsp): fix hover-on-read hook — strip cat-n prefix and correct MCP param#1541
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fix(lsp): fix hover-on-read hook — strip cat-n prefix and correct MCP param#1541
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The hover-on-read hook was completely non-functional due to two bugs:
1. extract_symbol_positions() applied the symbol regex against the full
Read tool output which uses cat-n format (" N\t" prefix). Since the
regex is anchored at `^`, no line started with a Rust keyword and the
function always returned an empty vec, causing an early return before
any MCP calls were made.
Fix: iterate lines, detect and strip the digit-only prefix before the
first tab, convert the 1-based line number to 0-based for LSP, then
apply the regex against the stripped source line. Also removes the now-
redundant `(?m)` flag since matching is per-line.
2. The MCP `get_hover` call passed `"path"` instead of `"file_path"`, which
is the required parameter name in the mcpls tool schema.
Fixes #1532
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This was referenced Mar 11, 2026
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Fixes #1532
Summary
The
hover-on-readLSP hook was completely non-functional due to two stacked bugs:Bug 1 — regex fails on cat-n output: The native
readtool returns content incat -nformat withN\tprefix. The symbol regex was applied to the full content and anchored at^, so no line ever matched —extract_symbol_positions()always returned an empty vec, causing an early return before any MCP calls.Fix: iterate lines, detect digit-only prefix before the first tab, strip it, convert 1-based line number to 0-based for LSP, apply the regex against the stripped source line. Also removes the now-redundant
(?m)multiline flag.Bug 2 — wrong MCP parameter name: The
get_hovercall passed"path"instead of"file_path", which is the required key in the mcpls tool schema.Test plan
cargo nextest run --workspace --features full --lib --bins -E 'test(hover)')handles_cat_n_prefix,cat_n_character_offset_starts_at_zero,non_digit_tab_prefix_no_symbol_match,empty_prefix_before_tab_no_symbol_match,max_symbols_zero_returns_empty,mixed_cat_n_and_raw_lines_not_supportedcargo clippy --workspace --features full -- -D warningspasses/lspshowshover injected: Nafter reading a.rsfile