chore(deps-dev): bump eslint from 8.42.0 to 9.0.0; update to new esli…

…nt flat file config (#3954)

In eslint@9 there is a new suggested config file format ("flat")
https://github.com/eslint/rfcs/tree/main/designs/2019-config-simplification
https://eslint.org/docs/latest/use/configure/configuration-files

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: David Luna <luna.bistuer@gmail.com>
Co-authored-by: Trent Mick <trent.mick@elastic.co>

.github/workflows/test.yml

@@ -37,7 +37,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 18
       - run: npm ci
       - run: npm run lint
 

eslint.config.js

@@ -0,0 +1,124 @@
+/*
+ * Copyright Elasticsearch B.V. and other contributors where applicable.
+ * Licensed under the BSD 2-Clause License; you may not use this file except in
+ * compliance with the BSD 2-Clause License.
+ */
+
+const globals = require('globals');
+const eslintJs = require('@eslint/js');
+const prettierConfig = require('eslint-config-prettier');
+const licenseHeaderPlugin = require('eslint-plugin-license-header');
+const nPlugin = require('eslint-plugin-n');
+const promisePlugin = require('eslint-plugin-promise');
+const importPlugin = require('eslint-plugin-import');
+const prettierPlugin = require('eslint-plugin-prettier');
+
+module.exports = [
+  {
+    // This block should *only* have the "ignores" property.
+    // https://eslint.org/docs/latest/use/configure/configuration-files#globally-ignoring-files-with-ignores
+    ignores: [
+      '*.example.js', // a pattern for uncommited local dev files to avoid linting
+      '*.example.mjs', // a pattern for uncommited local dev files to avoid linting
+
+      'test_output/**',
+      'tmp/**',
+      '.nyc_output/**',
+      'build/**',
+      'node_modules/**',
+      '**/elastic-apm-node.js',
+      '**/.next/**',
+
+      'examples/esbuild/dist/**',
+      'examples/typescript/dist/**',
+      'examples/an-azure-function-app/**',
+      'lib/opentelemetry-bridge/opentelemetry-core-mini/**',
+      'test/babel/out.js',
+      'test/lambda/fixtures/esbuild-bundled-handler/hello.js',
+      'test/sourcemaps/fixtures/lib/**',
+      'test/sourcemaps/fixtures/src/**',
+      'test/stacktraces/fixtures/dist/**',
+      'test/types/transpile/index.js',
+      'test/types/transpile-default/index.js',
+    ],
+  },
+  {
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+      globals: {
+        ...globals.node,
+        fetch: false, // not present in node globals (readonly)
+      },
+      parserOptions: {
+        ecmaFeatures: {
+          jsx: true, // to parse nextjs files
+        },
+      },
+    },
+    plugins: {
+      'license-header': licenseHeaderPlugin,
+      n: nPlugin,
+      promise: promisePlugin,
+      import: importPlugin,
+      prettier: prettierPlugin,
+    },
+    rules: {
+      ...eslintJs.configs.recommended.rules,
+      ...prettierConfig.rules,
+      'prettier/prettier': ['error'],
+      'license-header/header': ['error', './dev-utils/license-header.js'],
+
+      // Restoring some config from standardjs that we want to maintain at least
+      // for now -- to assist with transition to prettier.
+      'no-unused-vars': [
+        // See taav for possible better 'no-unused-vars' rule.
+        'error',
+        {
+          args: 'none',
+          caughtErrors: 'none',
+          ignoreRestSiblings: true,
+          vars: 'all',
+        },
+      ],
+      'no-empty': [
+        'error',
+        {
+          allowEmptyCatch: true,
+        },
+      ],
+      'no-constant-condition': [
+        'error',
+        {
+          checkLoops: false,
+        },
+      ],
+      'n/handle-callback-err': ['error', '^(err|error)$'],
+      'n/no-callback-literal': ['error'],
+      'n/no-deprecated-api': ['error'],
+      'n/no-exports-assign': ['error'],
+      'n/no-new-require': ['error'],
+      'n/no-path-concat': ['error'],
+      'n/process-exit-as-throw': ['error'],
+      'promise/param-names': ['error'],
+      // Undo this config from eslint:recommended for now (standardjs didn't have it.)
+      'require-yield': ['off'],
+      'import/export': 'error',
+      'import/first': 'error',
+      'import/no-absolute-path': [
+        'error',
+        { esmodule: true, commonjs: true, amd: false },
+      ],
+      'import/no-duplicates': 'error',
+      'import/no-named-default': 'error',
+      'import/no-webpack-loader-syntax': 'error',
+      // Some defaults have changed in v9
+      'dot-notation': ['error'],
+      'new-cap': ['error', { capIsNew: false }],
+      'no-eval': ['error', { allowIndirect: true }],
+      'no-new': ['error'],
+      yoda: ['error'],
+      'valid-typeof': ['error'],
+    },
+  },
+];

examples/nextjs/next.config.js

@@ -1,7 +1,13 @@
+/*
+ * Copyright Elasticsearch B.V. and other contributors where applicable.
+ * Licensed under the BSD 2-Clause License; you may not use this file except in
+ * compliance with the BSD 2-Clause License.
+ */
+
 /** @type {import('next').NextConfig} */
 const nextConfig = {
   reactStrictMode: true,
   swcMinify: true,
-}
+};
 
-module.exports = nextConfig
+module.exports = nextConfig;

examples/nextjs/pages/_app.js

@@ -1,7 +1,13 @@
-import '../styles/globals.css'
+/*
+ * Copyright Elasticsearch B.V. and other contributors where applicable.
+ * Licensed under the BSD 2-Clause License; you may not use this file except in
+ * compliance with the BSD 2-Clause License.
+ */
+
+import '../styles/globals.css';
 
 function MyApp({ Component, pageProps }) {
-  return <Component {...pageProps} />
+  return <Component {...pageProps} />;
 }
 
-export default MyApp
+export default MyApp;

examples/nextjs/pages/api/hello.js

@@ -1,5 +1,11 @@
+/*
+ * Copyright Elasticsearch B.V. and other contributors where applicable.
+ * Licensed under the BSD 2-Clause License; you may not use this file except in
+ * compliance with the BSD 2-Clause License.
+ */
+
 // Next.js API route support: https://nextjs.org/docs/api-routes/introduction
 
 export default function handler(req, res) {
-  res.status(200).json({ name: 'John Doe' })
+  res.status(200).json({ name: 'John Doe' });
 }

examples/nextjs/pages/index.js

@@ -1,6 +1,13 @@
-import Head from 'next/head'
-import Image from 'next/image'
-import styles from '../styles/Home.module.css'
+/*
+ * Copyright Elasticsearch B.V. and other contributors where applicable.
+ * Licensed under the BSD 2-Clause License; you may not use this file except in
+ * compliance with the BSD 2-Clause License.
+ */
+
+/* eslint-disable no-unused-vars */
+import Head from 'next/head';
+import Image from 'next/image';
+import styles from '../styles/Home.module.css';
 
 export default function Home() {
   return (
@@ -65,5 +72,5 @@ export default function Home() {
         </a>
       </footer>
     </div>
-  )
+  );
 }

lib/instrumentation/run-context/AbstractRunContextManager.js

@@ -32,7 +32,8 @@ class AbstractRunContextManager {
   constructor(log, runContextClass = RunContext) {
     this._log = log;
     this._kListeners = Symbol('ElasticListeners');
-    this._root = new runContextClass(); // eslint-disable-line new-cap
+    // eslint-disable-next-line new-cap
+    this._root = new runContextClass();
   }
 
   // Get the root run context. This is always empty (no current trans or span).

lib/opentelemetry-bridge/OTelSpan.js

@@ -49,7 +49,6 @@ function isHomogeneousArrayOfStrNumBool(arr) {
         return false;
       }
     } else if (typeof elem !== elemType) {
-      // eslint-disable-line valid-typeof
       return false;
     }
   }