From fb98dfcb7ce10b9ef8ae515585844aa28bf430ac Mon Sep 17 00:00:00 2001
From: NovemLinguae <79697282+NovemLinguae@users.noreply.github.com>
Date: Tue, 10 Dec 2024 03:16:33 -0800
Subject: [PATCH] eslint: fix no-return-assign (#2103)

* eslint: fix no-return-assign

manual fix

* use sum++ instead of ternary, easier to read

* use .filter() instead of .reduce()

* fix linter error

* add test
---
 .eslintrc.json           | 1 -
 modules/twinkletag.js    | 2 +-
 tests/twinkletag.test.js | 9 ++++++++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/.eslintrc.json b/.eslintrc.json
index 4d69942fb..e3f7dd7bb 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -54,7 +54,6 @@
 		"no-jquery/no-sizzle": "warn",
 		"no-loop-func": "warn",
 		"no-new": "warn",
-		"no-return-assign": "warn",
 		"no-script-url": "warn",
 		"no-unused-expressions": "warn",
 		"no-use-before-define": "warn",
diff --git a/modules/twinkletag.js b/modules/twinkletag.js
index 2e7caea29..52ec8b969 100644
--- a/modules/twinkletag.js
+++ b/modules/twinkletag.js
@@ -2009,7 +2009,7 @@ Twinkle.tag.callbacks = {
  * @return {true|undefined}
  */
 Twinkle.tag.checkIncompatible = function(incompatibleTags, tagsToCheck, extraMessage = null) {
-	const count = incompatibleTags.reduce((sum, tag) => sum += tagsToCheck.indexOf(tag) !== -1, 0);
+	const count = incompatibleTags.filter((tag) => tagsToCheck.includes(tag)).length;
 	if (count > 1) {
 		const incompatibleTagsString = '{{' + incompatibleTags.join('}}, {{') + '}}';
 		let message = 'Please select only one of: ' + incompatibleTagsString + '.';
diff --git a/tests/twinkletag.test.js b/tests/twinkletag.test.js
index f890b1126..16f913d55 100644
--- a/tests/twinkletag.test.js
+++ b/tests/twinkletag.test.js
@@ -1,6 +1,13 @@
 describe('modules/twinkletag', () => {
 	describe('checkIncompatible', () => {
-		test('no conflicts', () => {
+		test('no conflicts, 0 tags to check', () => {
+			const incompatibleTags = ['Bad GIF', 'Bad JPEG', 'Bad SVG', 'Bad format'];
+			const tagsToCheck = [];
+			const expected = undefined;
+			expect(Twinkle.tag.checkIncompatible(incompatibleTags, tagsToCheck)).toBe(expected);
+		});
+		
+		test('no conflicts, 1 tag to check', () => {
 			const incompatibleTags = ['Bad GIF', 'Bad JPEG', 'Bad SVG', 'Bad format'];
 			const tagsToCheck = ['Better source requested'];
 			const expected = undefined;