Race condition: onDefinition returns empty when called before validatePerlDocument completes

[yakirgb]

Problem

textDocument/definition returns empty results when called shortly after textDocument/didOpen.

Reproduction: Any LSP client that sends definition requests within ~200ms of opening a document will intermittently get empty results, even when symbols exist.

Root Cause

In server.ts, documents.onDidOpen calls validatePerlDocument() without awaiting it. Since validatePerlDocument spawns a Perl process (300-500ms+), the onDefinition handler often runs before navSymbols is populated, causing it to return empty.

Proposed Fix

In server.ts, add a fallback in onDefinition to parse the document on-demand if navSymbols is not yet populated.

1. Add import at the top of the file:

import { parseDocument } from "./parser";

2. Modify the onDefinition handler - add fallback before calling getDefinition:

// Parse on-demand if navSymbols hasn't been populated yet
if (!perlDoc) {
    perlDoc = await parseDocument(document, ParseType.selfNavigation);
}

This uses the existing parseDocument function (which parses Perl syntax directly in Node.js) instead of waiting for the slow external Perl process to complete.

Happy to submit a PR if this approach looks good.

Thank you,
Yakir Gibraltar.

[bscan]

Hi @yakirgb, thanks for filing the issue. This is certainly a problem for users that quickly request additional info and for slow compiling files. I think I like this change, and it's aligned with previous changes for onDocumentSymbol. Before the fast node.js parsing was available, onDocumentSymbol function would simply wait until the full Perl compilation process was done before returning. Here's how that old code worked:

PerlNavigator/server/src/symbols.ts

Line 20 in 09d325e

if (++retries > 100) { // Wait for 10 seconds looking for the document.

. That function has since switched entirely to the fast parsing in node.js, so those features are now available much more quickly.

Thinking through some possible aspects:

1 - Not all definitions are found via selfNavigation parsing. Some definitions require the Perl compiler to identify the source of a function. The fix you proposed would essentially offer up a middle ground where only some symbols are available. Not necessarily a problem, more of an observation. I have an example below for testing.

# Test example for slow parsing
use strict;
use warnings;
use File::Basename;

BEGIN {
    sleep(5); # Force slow compilation
}

fileparse();  # Found via compilation, not node.js based parsing
foo();        # Could be found from parsing in node.js

sub foo {
    return 42; 
}

2 - In addition there's also the issue of some of the other features: onCompletion, onHover, onSignatureHelp. Although these would be easy to fix afterwards once an example is in place.

Overall, I like it and I think it's an improvement. Feel free to submit a PR. Thank you!