chore: lint code blocks in docs with ESLint

docs/.eslintrc.json

@@ -0,0 +1,21 @@
+{
+  "plugins": [
+    "markdown",
+    "unicorn"
+  ],
+  "overrides": [
+    {
+      "files": ["*.md", "**/*.md"],
+      "processor": "markdown/markdown"
+    }
+  ],
+  "rules": {
+    "@typescript-eslint/no-unused-vars": "off",
+    "indent": "off",
+    "no-undef": "off",
+    "no-unused-expressions": "off",
+    "no-unused-vars": "off",
+    "semi": "off",
+    "unicorn/prefer-node-protocol": "error"
+  }
+}

docs/api/app.md

@@ -1196,6 +1196,8 @@ For `infoType` equal to `complete`:
 For `infoType` equal to `basic`:
   Promise is fulfilled with `Object` containing fewer attributes than when requested with `complete`. Here's an example of basic response:
 
+<!-- eslint-skip -->
+
 ```js
 {
   auxAttributes:

docs/api/browser-window.md

@@ -1186,7 +1186,7 @@ method:
 const { BrowserWindow } = require('electron')
 const win = new BrowserWindow()
 
-const url = require('url').format({
+const url = require('node:url').format({
   protocol: 'file',
   slashes: true,
   pathname: require('node:path').join(__dirname, 'index.html')

docs/api/dialog.md

@@ -52,6 +52,8 @@ The `browserWindow` argument allows the dialog to attach itself to a parent wind
 The `filters` specifies an array of file types that can be displayed or
 selected when you want to limit the user to a specific type. For example:
 
+<!-- eslint-skip -->
+
 ```js
 {
   filters: [
@@ -119,6 +121,8 @@ The `browserWindow` argument allows the dialog to attach itself to a parent wind
 The `filters` specifies an array of file types that can be displayed or
 selected when you want to limit the user to a specific type. For example:
 
+<!-- eslint-skip -->
+
 ```js
 {
   filters: [

docs/api/protocol.md

@@ -34,7 +34,7 @@ to register it to that session explicitly.
 ```js
 const { app, BrowserWindow, net, protocol, session } = require('electron')
 const path = require('node:path')
-const url = require('url')
+const url = require('node:url')
 
 app.whenReady().then(() => {
   const partition = 'persist:example'
@@ -124,7 +124,7 @@ Example:
 ```js
 const { app, net, protocol } = require('electron')
 const path = require('node:path')
-const { pathToFileURL } = require('url')
+const { pathToFileURL } = require('node:url')
 
 protocol.registerSchemesAsPrivileged([
   {
@@ -280,7 +280,7 @@ Example:
 
 ```js
 const { protocol } = require('electron')
-const { PassThrough } = require('stream')
+const { PassThrough } = require('node:stream')
 
 function createStream (text) {
   const rv = new PassThrough() // PassThrough is also a Readable stream

docs/api/session.md

@@ -879,7 +879,7 @@ To clear the handler, call `setPermissionCheckHandler(null)`.
 
 ```js
 const { session } = require('electron')
-const url = require('url')
+const url = require('node:url')
 session.fromPartition('some-partition').setPermissionCheckHandler((webContents, permission, requestingOrigin) => {
   if (new URL(requestingOrigin).hostname === 'some-host' && permission === 'notifications') {
     return true // granted

docs/api/structures/printer-info.md

@@ -14,6 +14,8 @@ The number represented by `status` means different things on different platforms
 Below is an example of some of the additional options that may be set which
 may be different on each platform.
 
+<!-- eslint-skip -->
+
 ```js
 {
   name: 'Austin_4th_Floor_Printer___C02XK13BJHD4',

docs/api/structures/trace-config.md

@@ -26,6 +26,8 @@
 
 An example TraceConfig that roughly matches what Chrome DevTools records:
 
+<!-- eslint-skip -->
+
 ```js
 {
   recording_mode: 'record-until-full',

docs/api/web-frame.md

@@ -212,6 +212,8 @@ console.log(webFrame.getResourceUsage())
 
 This will generate:
 
+<!-- eslint-skip -->
+
 ```js
 {
   images: {

docs/development/creating-api.md

@@ -166,6 +166,6 @@ Add your module to the module list found at `"lib/browser/api/module-list.ts"` l
 
 ```ts title='lib/browser/api/module-list.ts' @ts-nocheck
 export const browserModuleList: ElectronInternal.ModuleEntry[] = [
-  { name: 'apiName', loader: () => require('./api-name') },
+  { name: 'apiName', loader: () => require('./api-name') }
 ];
 ```

docs/tutorial/esm.md

@@ -85,6 +85,8 @@ The `@babel/plugin-transform-modules-commonjs` plugin will transform
 ESM imports down to `require` calls. The exact syntax will depend on the
 [`importInterop` setting](https://babeljs.io/docs/babel-plugin-transform-modules-commonjs#importinterop).
 
+<!-- eslint-disable no-var, quotes -->
+
 ```js @nolint @ts-nocheck title='@babel/plugin-transform-modules-commonjs'
 import foo from "foo";
 import { bar } from "bar";

docs/tutorial/ipc.md

@@ -412,6 +412,8 @@ function createWindow () {
 For the purposes of the tutorial, it's important to note that the `click` handler
 sends a message (either `1` or `-1`) to the renderer process through the `update-counter` channel.
 
+<!-- eslint-skip -->
+
 ```js @ts-type={mainWindow:Electron.BrowserWindow}
 click: () => mainWindow.webContents.send('update-counter', -1)
 ```

docs/tutorial/security.md

@@ -280,7 +280,7 @@ security-conscious developers might want to assume the very opposite.
 
 ```js title='main.js (Main Process)'
 const { session } = require('electron')
-const { URL } = require('url')
+const { URL } = require('node:url')
 
 session
   .fromPartition('some-partition')
@@ -610,7 +610,7 @@ sometimes be fooled - a `startsWith('https://example.com')` test would let
 `https://example.com.attacker.com` through.
 
 ```js title='main.js (Main Process)'
-const { URL } = require('url')
+const { URL } = require('node:url')
 const { app } = require('electron')
 
 app.on('web-contents-created', (event, contents) => {

package.json

@@ -43,6 +43,7 @@
     "eslint": "^8.41.0",
     "eslint-config-standard": "^14.1.1",
     "eslint-plugin-import": "^2.26.0",
+    "eslint-plugin-markdown": "^5.0.0",
     "eslint-plugin-mocha": "^7.0.1",
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-promise": "^4.2.1",

script/lint.js

@@ -73,6 +73,24 @@ function spawnAndCheckExitCode (cmd, args, opts) {
   }
 }
 
+async function runEslint (eslint, filenames, { fix, verbose }) {
+  const formatter = await eslint.loadFormatter();
+  let successCount = 0;
+  const results = await eslint.lintFiles(filenames);
+  for (const result of results) {
+    successCount += result.errorCount === 0 ? 1 : 0;
+    if (verbose && result.errorCount === 0 && result.warningCount === 0) {
+      console.log(`${result.filePath}: no errors or warnings`);
+    }
+  }
+  console.log(formatter.format(results));
+  if (fix) {
+    await ESLint.outputFixes(results);
+  }
+
+  return successCount === filenames.length;
+}
+
 function cpplint (args) {
   args.unshift(`--root=${SOURCE_ROOT}`);
   const cmd = IS_WINDOWS ? 'cpplint.bat' : 'cpplint.py';
@@ -141,20 +159,8 @@ const LINTERS = [{
       overrideConfigFile: path.join(ELECTRON_ROOT, '.eslintrc.json'),
       resolvePluginsRelativeTo: ELECTRON_ROOT
     });
-    const formatter = await eslint.loadFormatter();
-    let successCount = 0;
-    const results = await eslint.lintFiles(filenames);
-    for (const result of results) {
-      successCount += result.errorCount === 0 ? 1 : 0;
-      if (opts.verbose && result.errorCount === 0 && result.warningCount === 0) {
-        console.log(`${result.filePath}: no errors or warnings`);
-      }
-    }
-    console.log(formatter.format(results));
-    if (opts.fix) {
-      await ESLint.outputFixes(results);
-    }
-    if (successCount !== filenames.length) {
+    const clean = await runEslint(eslint, filenames, { fix: opts.fix, verbose: opts.verbose });
+    if (!clean) {
       console.error('Linting had errors');
       process.exit(1);
     }
@@ -357,6 +363,26 @@ const LINTERS = [{
       }
     }
 
+    const eslint = new ESLint({
+      // Do not use the lint cache on CI builds
+      cache: !process.env.CI,
+      cacheLocation: `node_modules/.eslintcache.${crypto.createHash('md5').update(fs.readFileSync(__filename)).digest('hex')}`,
+      fix: opts.fix,
+      overrideConfigFile: path.join(ELECTRON_ROOT, 'docs', '.eslintrc.json'),
+      resolvePluginsRelativeTo: ELECTRON_ROOT
+    });
+    const clean = await runEslint(
+      eslint,
+      docs.filter(
+        // TODO(dsanders11): Once we move to newer ESLint and the flat config,
+        // switch to using `ignorePatterns` and `warnIgnore: false` instead of
+        // explicitly filtering out this file that we don't want to lint
+        (filename) => !filename.endsWith('docs/breaking-changes.md')
+      ),
+      { fix: opts.fix, verbose: opts.verbose }
+    );
+    errors ||= !clean;
+
     if (errors) {
       process.exit(1);
     }