Use gts instead of eslint

.editorconfig

@@ -5,6 +5,7 @@ root = true
 [*]
 charset = utf-8
 indent_size = 2
+end_of_line = lf
 indent_style = space
 insert_final_newline = true
 trim_trailing_whitespace = true

.eslintrc.json

@@ -0,0 +1,3 @@
+{
+  "extends": "./node_modules/gts/"
+}

.prettierrc.js

@@ -0,0 +1,3 @@
+module.exports = {
+  ...require('gts/.prettierrc.json'),
+};

package.json

@@ -28,14 +28,14 @@
     "build:11ty": "NODE_OPTIONS='-r ts-node/register' eleventy",
     "watch:11ty": "yarn build:11ty --serve --incremental",
     "tsc": "tsc",
+    "gts": "gts fix",
+    "gts:ci": "gts lint",
     "prettier": "prettier --write .",
     "prettier:ci": "prettier --check .",
-    "eslint": "eslint --fix .",
-    "eslint:ci": "eslint .",
     "stylelint": "stylelint '**/*.{css,scss}' --fix",
     "stylelint:ci": "stylelint '**/*.{css,scss}'",
-    "lint": "run-s prettier eslint stylelint tsc",
+    "lint": "run-s prettier gts stylelint tsc",
-    "lint:ci": "run-s prettier:ci eslint:ci stylelint:ci tsc",
+    "lint:ci": "run-s prettier:ci gts:ci stylelint:ci tsc",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "devDependencies": {
@@ -68,6 +68,7 @@
     "eslint-import-resolver-typescript": "^3.5.5",
     "eslint-plugin-import": "^2.27.5",
     "eslint-plugin-simple-import-sort": "^10.0.0",
+    "gts": "^3.1.1",
     "jquery": "^3.7.0",
     "jquery-ui": "^1.13.2",
     "js-yaml": "^4.1.0",

source/assets/js/components/sass-syntax-switcher.ts

@@ -6,12 +6,9 @@ $(function () {
       active: 0,
       beforeActivate: function (event, ui) {
         // If multiple panels are visible, the CSS tab shouldn't be clickable.
-        if (
+        return !(
-          ui.newPanel.hasClass('css') &&
+          ui.newPanel.hasClass('css') && allPanels.filter(':visible').length > 1
-          allPanels.filter(':visible').length > 1
+        );
-        ) {
-          return false;
-        }
       },
       activate: function (event, ui) {
         if (ui.newPanel.hasClass('css')) {

tsconfig.json

@@ -1,9 +1,10 @@
 {
-  "extends": "ts-node/node16/tsconfig.json",
+  "extends": "./node_modules/gts/tsconfig-google.json",
   "ts-node": {
     "transpileOnly": true
   },
   "compilerOptions": {
+    "esModuleInterop": true,
     "target": "es2022",
     "lib": ["es2022", "DOM"],
     "isolatedModules": true,