chore: replace airbnb with xo style

.prettierrc.json

@@ -1,7 +1,9 @@
 {
   "printWidth": 80,
+  "useTabs": false,
   "tabWidth": 2,
   "semi": true,
   "singleQuote": true,
-  "trailingComma": "es5"
+  "bracketSpacing": true,
+  "trailingComma": "all"
 }

.xo-config.json

@@ -0,0 +1,30 @@
+{
+  "prettier": true,
+  "rules": {
+    "capitalized-comments": "off",
+    "eqeqeq": ["error", "always", { "null": "ignore" }],
+    "import/order": ["error", { "newlines-between": "ignore" }],
+    "no-eq-null": "off",
+    "no-shadow": ["error"],
+    "unicorn/no-negated-condition": "off",
+    "unicorn/prefer-module": "off",
+    "unicorn/prevent-abbreviations": "off"
+  },
+  "overrides": [
+    {
+      "prettier": true,
+      "files": "test/**/*.js",
+      "envs": ["node", "mocha"],
+      "rules": {
+        "func-names": "off",
+        "prefer-arrow-callback": "off"
+      }
+    },
+    {
+      "files": "examples/**/*.js",
+      "rules": {
+        "no-new": "off"
+      }
+    }
+  ]
+}

lib/cli.js

@@ -1,15 +1,15 @@
 #!/usr/bin/env node
 
 /* eslint-env node */
-/* eslint-disable no-console */
 
-const path = require('path');
+const path = require('node:path');
+const process = require('node:process');
 const yargs = require('yargs/yargs');
 
 const { loadOptions, YARGS_PARSER_CONFIG } = require('mocha/lib/cli/options');
 
 const { version } = require('../package.json');
-const run = require('./run');
+const run = require('./run.js');
 
 exports.main = (argv = process.argv.slice(2)) => {
   // ensure we can require() from current working directory

lib/mocha-json-runner.js

@@ -58,12 +58,12 @@ class MochaJsonRunner extends Mocha.Runner {
       };
     }
 
-    this.failHooks = function failHooks(hooks) {
-      hooks.forEach((hook) => {
+    this.failHooks = function (hooks) {
+      for (const hook of hooks) {
         hook.run((err) => {
           this.failHook(hook, err);
         });
-      });
+      }
     };
 
     /**
@@ -76,7 +76,7 @@ class MochaJsonRunner extends Mocha.Runner {
      * @param {Function} fn
      * @return {Runner} Runner instance.
      */
-    this.run = function run(fn = () => {}) {
+    this.run = function (fn = () => {}) {
       this.emit(EVENT_RUN_BEGIN);
 
       const runSuite = (suite) => {
@@ -90,24 +90,26 @@ class MochaJsonRunner extends Mocha.Runner {
         if (failingBeforeAllHooks.length > 0) {
           this.failHooks(failingBeforeAllHooks);
         } else {
-          // eslint-disable-next-line no-restricted-syntax
           for (const test of suite.tests) {
             switch (test.state) {
-              case STATE_PASSED:
+              case STATE_PASSED: {
                 this.emit(EVENT_TEST_PASS, test);
                 if (!hasStats) this.stats.passes += 1;
                 break;
+              }
 
-              case STATE_FAILED:
+              case STATE_FAILED: {
                 test.run((err) => {
                   this.fail(test, err); // Runner will emit EVENT_TEST_FAIL
                   if (!hasStats) this.stats.failures += 1;
                 });
                 break;
+              }
 
-              default:
+              default: {
                 if (test.pending) {
                   this.emit(EVENT_TEST_PENDING, test);
+                  // eslint-disable-next-line max-depth
                   if (!hasStats) this.stats.pending += 1;
                 } else if (failingBeforeEachHooks.length > 0) {
                   this.failHooks(failingBeforeEachHooks);
@@ -117,14 +119,15 @@ class MochaJsonRunner extends Mocha.Runner {
                   break; // skip remaining tests in suite
                 } else if (config.warnOnMissingState) {
                   // could be a test that did not match a grep
-                  // eslint-disable-next-line no-console
                   console.error(
                     `Unexpected test.state: ${
                       test.state
-                    } and not pending. test: ${test.fullTitle()}`
+                    } and not pending. test: ${test.fullTitle()}`,
                   );
                 }
+              }
             }
+
             this.emit(EVENT_TEST_END, test);
             if (!hasStats) this.stats.tests += 1;
           }
@@ -133,9 +136,9 @@ class MochaJsonRunner extends Mocha.Runner {
             failingBeforeEachHooks.length === 0 &&
             failingAfterEachHooks.length === 0
           ) {
-            suite.suites.forEach((childSuite) => {
+            for (const childSuite of suite.suites) {
               runSuite(childSuite);
-            });
+            }
           }
         }
 

lib/run.js

@@ -1,5 +1,5 @@
+/* eslint-disable unicorn/no-process-exit */
 /* eslint-env node */
-/* eslint-disable no-console */
 
 /**
  * Definition for Mocha's default ("run tests") command
@@ -8,8 +8,8 @@
  * @private
  */
 
-const fs = require('fs');
-
+const fs = require('node:fs');
+const process = require('node:process');
 const Mocha = require('mocha');
 const { createInvalidArgumentValueError } = require('mocha/lib/errors');
 
@@ -26,12 +26,10 @@ const {
 const defaults = require('mocha/lib/mocharc');
 const { types, aliases } = require('mocha/lib/cli/run-option-metadata');
 
-const MochaJsonRunner = require('./mocha-json-runner');
+const MochaJsonRunner = require('./mocha-json-runner.js');
 
 // Mocha v8.2 changed the name of this function to `validateLegacyPlugin`
-if (validateLegacyPlugin == null) {
-  validateLegacyPlugin = validatePlugin;
-}
+validateLegacyPlugin ??= validatePlugin;
 
 /**
  * Logical option groups
@@ -88,24 +86,27 @@ exports.builder = (yargs) =>
         description: 'List built-in reporters & exit',
       },
       'reporter-option': {
-        coerce: (opts) => {
+        coerce(opts) {
           if (opts == null) return undefined;
 
-          return list(opts).reduce((acc, opt) => {
+          const result = {};
+          const optsList = list(opts);
+          for (const opt of optsList) {
             const pair = opt.split('=');
 
-            if (pair.length > 2 || !pair.length) {
+            if (pair.length > 2 || pair.length === 0) {
               throw createInvalidArgumentValueError(
                 `invalid reporter option '${opt}'`,
                 '--reporter-option',
                 opt,
-                'expected "key=value" format'
+                'expected "key=value" format',
               );
             }
 
-            acc[pair[0]] = pair.length === 2 ? pair[1] : true;
-            return acc;
-          }, {});
+            result[pair[0]] = pair.length === 2 ? pair[1] : true;
+          }
+
+          return result;
         },
         description: 'Reporter-specific options (<k=v,[k1=v1,..]>)',
         group: GROUPS.OUTPUT,
@@ -129,12 +130,12 @@ exports.builder = (yargs) =>
     })
     .check((argv) => {
       // "one-and-dones"; let yargs handle help and version
-      Object.keys(ONE_AND_DONES).forEach((opt) => {
+      for (const opt of Object.keys(ONE_AND_DONES)) {
         if (argv[opt]) {
           ONE_AND_DONES[opt].call(null, yargs);
           process.exit();
         }
-      });
+      }
 
       // load requires first, because it can impact "plugin" validation
       handleRequires(argv.require);
@@ -159,8 +160,8 @@ exports.handler = (argv) => {
   let json;
   try {
     const file = argv.json;
-    json = fs.readFileSync(file, 'utf-8');
-  } catch (err) {
+    json = fs.readFileSync(file, 'utf8');
+  } catch {
     console.error('Error: No test files found');
     process.exit(1);
   }