fix(diagnostics): function signatures, save-gated propagation, external tool scheduling, and @phpstan-ignore parsing

[calebdw]

Summary

Five diagnostic improvements, each in its own commit:

1. Function signature change detection (update_ast)

Root cause: update_ast only tracked class signature changes. When a standalone function's parameter type changed (e.g. bar(null $x) to bar(string $x)), update_ast returned false, so schedule_diagnostics_for_open_files was never called and other open files kept showing stale diagnostics.

• Add FunctionInfo::signature_eq() for comparing function signatures
• Track function signature changes in update_ast: snapshot old functions before re-parse, compare signatures, clean up stale entries
• Add did_save handler as a reliable diagnostic refresh point
• Register save notification capability in TextDocumentSyncOptions
• 23 tests covering signature_eq and update_ast change detection

Closes #123

2. Cross-file diagnostics only on save

Move schedule_diagnostics_for_open_files out of the didChange handler so that editing a function or class signature in one file no longer immediately refreshes diagnostics in other open files. This avoids propagating intermediate/incomplete edits to other buffers. Same-file diagnostics continue to update on every keystroke.

3. External tools run on save only, no debounce

External tool workers (PHPStan, PHPCS, Mago lint, Mago analyze) are now scheduled exclusively from did_save. They are expensive (seconds per run) and serialized (one process at a time), so running them on every keystroke would block save-triggered runs. All external tool debounce constants and logic have been removed — workers fire immediately on save.

Also adds workspace/diagnostic/refresh after each external tool worker caches new results, so editors using pull diagnostics see updates without requiring a didChange event.

4. Disable workspace diagnostics capability

Set workspace_diagnostics to false. The workspace/diagnostic handler currently only returns cached diagnostics for open files — the same data textDocument/diagnostic provides per-file. Advertising the capability causes editors to send redundant workspace-wide pull requests. Can be flipped to true when the server gains project-wide analysis (e.g. whole-project PHPStan).

5. Parse @phpstan-ignore with per-identifier reasons

The stale diagnostic filter failed to match @phpstan-ignore comments with the per-identifier reason syntax:

/** @phpstan-ignore return.type (reason text here) */

The parser stopped at */ before checking for (, so the parenthesized reason text was included in the identifier list. When the reason contained commas, identifiers split incorrectly and none matched. Fix: split by comma first, then strip the optional (reason) suffix from each entry. Three new tests cover this.

[codecov-commenter]

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Codecov Report

❌ Patch coverage is 93.70079% with 24 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/diagnostics/mod.rs	79.31%	24 Missing ⚠️

📢 Thoughts on this report? Let us know!

[Disservin]

hi @calebdw this already works much better! however the diagnostics now change immediately, even before the file is saved

for example in my bug report if you fix test2.php but you don't save the file the error from test.php will still disappear, which I consider to be wrong

i'd expect the following:

If the two functions are inside the same php file and bar gets fixed then the error in foo should immediately disappear.. however if the definition is coming from a different file it should only propagate this once the file is saved.

[calebdw]

@Disservin, thanks for the feedback! Please try now---it was existing behaviour, but I agree that cross-file diagnostics should only happen on save and not every change

[Disservin]

looks good imo