tools,doc: forbid CJS globals in ESM code snippets

.eslintrc.js

@@ -76,6 +76,29 @@ module.exports = {
         'doc/api/packages.md/*.js',
       ],
       parserOptions: { sourceType: 'module' },
+      rules: { 'no-restricted-globals': [
+        'error',
+        {
+          name: '__filename',
+          message: 'Use import.meta.url instead',
+        },
+        {
+          name: '__dirname',
+          message: 'Not available in ESM',
+        },
+        {
+          name: 'exports',
+          message: 'Not available in ESM',
+        },
+        {
+          name: 'module',
+          message: 'Not available in ESM',
+        },
+        {
+          name: 'require',
+          message: 'Use import instead',
+        },
+      ] },
     },
   ],
   rules: {

doc/api/crypto.md

@@ -1518,9 +1518,7 @@ hash.end();
 Example: Using `Hash` and piped streams:
 
 ```mjs
-const {
-  createReadStream,
-} = require('fs');
+import { createReadStream } from 'fs';
 
 const {
   createHash,
@@ -1551,7 +1549,7 @@ Example: Using the [`hash.update()`][] and [`hash.digest()`][] methods:
 ```mjs
 const {
   createHash,
-} = require('crypto');
+} = await import('crypto');
 
 const hash = createHash('sha256');
 
@@ -1596,7 +1594,7 @@ its [`hash.digest()`][] method has been called.
 // Calculate a rolling hash.
 const {
   createHash,
-} = require('crypto');
+} = await import('crypto');
 
 const hash = createHash('sha256');
 
@@ -1691,7 +1689,7 @@ Example: Using `Hmac` objects as streams:
 ```mjs
 const {
   createHmac,
-} = require('crypto');
+} = await import('crypto');
 
 const hmac = createHmac('sha256', 'a secret');
 

doc/api/esm.md

@@ -387,7 +387,7 @@ analysis process.
 
 For example, consider a CommonJS module written:
 
-```js
+```cjs
 // cjs.cjs
 exports.name = 'exported';
 ```

doc/api/packages.md

@@ -704,7 +704,7 @@ import { another } from 'a-package/m.mjs';
 Self-referencing is also available when using `require`, both in an ES module,
 and in a CommonJS one. For example, this code will also work:
 
-```js
+```cjs
 // ./a-module.js
 const { something } = require('a-package/foo'); // Loads from ./foo.js.
 ```
@@ -807,7 +807,7 @@ to be treated as ES modules, just as `"type": "commonjs"` would cause them
 to be treated as CommonJS.
 See [Enabling](#esm_enabling).
 
-```js
+```cjs
 // ./node_modules/pkg/index.cjs
 exports.name = 'value';
 ```
@@ -920,7 +920,7 @@ CommonJS and ES module instances of the package:
    CommonJS and ES module versions of the package. For example, if the CommonJS
    and ES module entry points are `index.cjs` and `index.mjs`, respectively:
 
-    ```js
+    ```cjs
     // ./node_modules/pkg/index.cjs
     const state = require('./state.cjs');
     module.exports.state = state;
@@ -1034,7 +1034,7 @@ The `"main"` field defines the script that is used when the [package directory
 is loaded via `require()`](modules.md#modules_folders_as_modules). Its value
 is a path.
 
-```js
+```cjs
 require('./path/to/directory'); // This resolves to ./path/to/directory/main.js.
 ```