From ab686d83e991eecd922d6848709f5417f61f77c6 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <DanielRosenwasser@users.noreply.github.com>
Date: Sat, 4 Feb 2023 02:27:29 +0000
Subject: [PATCH] Try tracking deferred nodes using 2 arrays: one to maintain
 order, the other as a simple sparse array.

---
 src/compiler/checker.ts | 17 ++++++++++++++---
 src/compiler/types.ts   |  2 +-
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index a01c44bf6aaff..016b946b4111c 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -44345,15 +44345,26 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const enclosingFile = getSourceFileOfNode(node);
         const links = getNodeLinks(enclosingFile);
         if (!(links.flags & NodeCheckFlags.TypeChecked)) {
-            links.deferredNodes ||= new Set();
-            links.deferredNodes.add(node);
+            links.deferredNodes ??= {
+                order: [],
+                set: [],
+            };
+            const { order, set } = links.deferredNodes;
+            const nodeId = getNodeId(node);
+            if (set[nodeId] === undefined) {
+                order.push(nodeId);
+                set[nodeId] = node;
+            }
         }
     }
 
     function checkDeferredNodes(context: SourceFile) {
         const links = getNodeLinks(context);
         if (links.deferredNodes) {
-            links.deferredNodes.forEach(checkDeferredNode);
+            const { order, set } = links.deferredNodes;
+            for (const nodeId of order) {
+                checkDeferredNode(set[nodeId]);
+            }
         }
     }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 0a43afe978ea4..62c0ead7955fc 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -5975,7 +5975,7 @@ export interface NodeLinks {
     jsxNamespace?: Symbol | false;      // Resolved jsx namespace symbol for this node
     jsxImplicitImportContainer?: Symbol | false; // Resolved module symbol the implicit jsx import of this file should refer to
     contextFreeType?: Type;             // Cached context-free type used by the first pass of inference; used when a function's return is partially contextually sensitive
-    deferredNodes?: Set<Node>;          // Set of nodes whose checking has been deferred
+    deferredNodes?: { order: number[]; set: Record<number, Node> };  // Set of nodes whose checking has been deferred
     capturedBlockScopeBindings?: Symbol[]; // Block-scoped bindings captured beneath this part of an IterationStatement
     outerTypeParameters?: TypeParameter[]; // Outer type parameters of anonymous object type
     isExhaustive?: boolean | 0;         // Is node an exhaustive switch statement (0 indicates in-process resolution)