feat(tools): ignore no-unused-vars on underscore (#48386)

.eslintrc.json

@@ -38,7 +38,16 @@
     "import/order": "error",
     "import/no-cycle": [2, { "maxDepth": 2 }],
     "react/prop-types": "off",
-    "no-only-tests/no-only-tests": "error"
+    "no-only-tests/no-only-tests": "error",
+    "no-unused-vars": "off",
+    "@typescript-eslint/no-unused-vars": [
+      "warn",
+      {
+        "argsIgnorePattern": "^_",
+        "varsIgnorePattern": "^_",
+        "caughtErrorsIgnorePattern": "^_"
+      }
+    ]
   },
   "overrides": [
     {

api-server/src/server/middlewares/error-handlers.js

@@ -24,8 +24,7 @@ const isDev = process.env.FREECODECAMP_NODE_ENV !== 'production';
 
 export default function prodErrorHandler() {
   // error handling in production.
-  // eslint-disable-next-line no-unused-vars
-  return function (err, req, res, next) {
+  return function (err, req, res, _next) {
     // response for when req.body is bigger than body-parser's size limit
     if (err?.type === 'entity.too.large') {
       return res.status('413').send('Request payload is too large');

client/src/__mocks__/gatsby.ts

@@ -1,4 +1,3 @@
-/* eslint-disable no-unused-vars */
 import React from 'react';
 import { GatsbyLinkProps } from 'gatsby';
 const gatsby: NodeModule = jest.requireActual('gatsby');

client/src/client/frame-runner.ts

@@ -34,7 +34,6 @@ export interface InitTestFrameArg {
 
 async function initTestFrame(e: InitTestFrameArg = { code: {} }) {
   const code = (e.code.contents || '').slice();
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const __file = (id?: string) => {
     if (id && e.code.original) {
       return e.code.original[id];
@@ -45,7 +44,6 @@ async function initTestFrame(e: InitTestFrameArg = { code: {} }) {
   const editableContents = (e.code.editableContents || '').slice();
   // __testEditable allows test authors to run tests against a transitory dom
   // element built using only the code in the editable region.
-  // eslint-disable-next-line @typescript-eslint/no-unused-vars
   const __testEditable = (cb: () => () => unknown) => {
     const div = document.createElement('div');
     div.id = 'editable-only';