fix(lsp): replace recursive fastwalk with filepath.Glob in root marker detection (#2316)

Austin Cherry created 2 weeks ago

hasRootMarkers used fsext.Glob which triggered a full recursive fastwalk
of the working directory with no gitignore filtering. In large JS
monorepos this walked millions of files in node_modules, causing 800%
CPU usage. Root markers are simple filenames (go.mod, package.json,
*.gpr, etc.) that only need a single-directory check.

🐘 Generated with Crush

Assisted-by: AWS Claude Opus 4.6 via Crush <[e-mail]>

Change summary

internal/lsp/manager.go | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

Detailed changes

internal/lsp/manager.go

@@ -303,8 +303,10 @@ func hasRootMarkers(dir string, markers []string) bool {
 		return true
 	}
 	for _, pattern := range markers {
-		// Use fsext.GlobWithDoubleStar to find matches
-		matches, _, err := fsext.Glob(pattern, dir, 1)
+		// Use filepath.Glob for a non-recursive check in the root
+		// directory. This avoids walking the entire tree (which is
+		// catastrophic in large monorepos with node_modules, etc.).
+		matches, err := filepath.Glob(filepath.Join(dir, pattern))
 		if err == nil && len(matches) > 0 {
 			return true
 		}