From b6341232bea7cb9f866e8c9001c1077b89b9fc48 Mon Sep 17 00:00:00 2001
From: lumir <rpfos@naver.com>
Date: Fri, 23 Oct 2026 16:25:32 +0900
Subject: [PATCH] perf: reduce `no-missing-label-refs` time complexity from
 quadratic to linear

---
 src/rules/no-missing-label-refs.js        | 16 +++++------
 tests/rules/no-missing-label-refs.test.js | 33 +++++++++++++++++++++++
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/src/rules/no-missing-label-refs.js b/src/rules/no-missing-label-refs.js
index f98fd8b0..4e1957de 100644
--- a/src/rules/no-missing-label-refs.js
+++ b/src/rules/no-missing-label-refs.js
@@ -139,11 +139,15 @@ export default /** @satisfies {NoMissingLabelRefsRuleDefinition} */ ({
 		const allowLabels = new Set(context.options[0].allowLabels);
 
 		/** @type {Array<{label:string,position:Position}>} */
-		let allMissingReferences = [];
+		const allMissingReferences = [];
 
 		return {
 			"root:exit"() {
 				for (const missingReference of allMissingReferences) {
+					if (allowLabels.has(missingReference.label)) {
+						continue;
+					}
+
 					context.report({
 						loc: missingReference.position,
 						messageId: "notFound",
@@ -168,15 +172,7 @@ export default /** @satisfies {NoMissingLabelRefsRuleDefinition} */ ({
 			},
 
 			definition(node) {
-				/*
-				 * Sometimes a poorly-formatted link will end up a text node instead of a link node
-				 * even though the label definition exists. Here, we remove any missing references
-				 * that have a matching label definition.
-				 */
-				allMissingReferences = allMissingReferences.filter(
-					missingReference =>
-						missingReference.label !== node.identifier,
-				);
+				allowLabels.add(node.identifier);
 			},
 		};
 	},
diff --git a/tests/rules/no-missing-label-refs.test.js b/tests/rules/no-missing-label-refs.test.js
index 07ce97e2..8b5f4ecc 100644
--- a/tests/rules/no-missing-label-refs.test.js
+++ b/tests/rules/no-missing-label-refs.test.js
@@ -46,6 +46,10 @@ ruleTester.run("no-missing-label-refs", rule, {
 		"foo][bar][baz]\n\n[baz]: http://baz.com",
 		"[][foo]\n\n[foo]: http://foo.com",
 		"[foo][bar\\]\n\n[foo]: http://foo.com",
+		"[foo]: http://foo.com\n\n[foo][bar",
+		"[foo]: http://foo.com\n\n[foo][bar\\]",
+		"[foo][bar\n\n[foo]: http://foo.com\n\n[foo][bar",
+		"[foo][bar\\]\n\n[foo]: http://foo.com\n\n[foo][bar\\]",
 		"\\[\\]",
 		`${"\\".repeat(3)}[${"\\".repeat(3)}]`,
 		`${"\\".repeat(5)}[${"\\".repeat(5)}]`,
@@ -257,6 +261,35 @@ ruleTester.run("no-missing-label-refs", rule, {
 				},
 			],
 		},
+		{
+			code: "[foo]\n[bar]\n[foo]",
+			errors: [
+				{
+					messageId: "notFound",
+					data: { label: "foo" },
+					line: 1,
+					column: 2,
+					endLine: 1,
+					endColumn: 5,
+				},
+				{
+					messageId: "notFound",
+					data: { label: "bar" },
+					line: 2,
+					column: 2,
+					endLine: 2,
+					endColumn: 5,
+				},
+				{
+					messageId: "notFound",
+					data: { label: "foo" },
+					line: 3,
+					column: 2,
+					endLine: 3,
+					endColumn: 5,
+				},
+			],
+		},
 		{
 			code: "- - - [foo]",
 			errors: [