From db89ce33f45a1604f544c70419271cae5de575f2 Mon Sep 17 00:00:00 2001
From: David Sherret <dsherret@users.noreply.github.com>
Date: Sun, 31 Mar 2024 13:04:42 -0400
Subject: [PATCH] chore(lsp): remove recursion in recurse_dependents (#23153)

Was investigating a separate stack overflow (that I've now found in the
node resolution code) and came across this. We should avoid recursion
(this is very old code).
---
 cli/lsp/documents.rs | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/cli/lsp/documents.rs b/cli/lsp/documents.rs
index 8feeab8de4..8479768a0f 100644
--- a/cli/lsp/documents.rs
+++ b/cli/lsp/documents.rs
@@ -648,16 +648,20 @@ pub fn to_lsp_range(range: &deno_graph::Range) -> lsp::Range {
 fn recurse_dependents(
   specifier: &ModuleSpecifier,
   map: &HashMap<ModuleSpecifier, HashSet<ModuleSpecifier>>,
-  dependents: &mut HashSet<ModuleSpecifier>,
-) {
-  if let Some(deps) = map.get(specifier) {
-    for dep in deps {
-      if !dependents.contains(dep) {
-        dependents.insert(dep.clone());
-        recurse_dependents(dep, map, dependents);
+) -> Vec<ModuleSpecifier> {
+  let mut dependents = HashSet::new();
+  let mut pending = VecDeque::new();
+  pending.push_front(specifier);
+  while let Some(specifier) = pending.pop_front() {
+    if let Some(deps) = map.get(specifier) {
+      for dep in deps {
+        if dependents.insert(dep) {
+          pending.push_front(dep);
+        }
       }
     }
   }
+  dependents.into_iter().cloned().collect()
 }
 
 #[derive(Debug)]
@@ -1106,10 +1110,8 @@ impl Documents {
     specifier: &ModuleSpecifier,
   ) -> Vec<ModuleSpecifier> {
     self.calculate_dependents_if_dirty();
-    let mut dependents = HashSet::new();
     if let Some(specifier) = self.resolve_specifier(specifier) {
-      recurse_dependents(&specifier, &self.dependents_map, &mut dependents);
-      dependents.into_iter().collect()
+      recurse_dependents(&specifier, &self.dependents_map)
     } else {
       vec![]
     }