chore: use 'use strict' in cjs files

docs/examples/proxy/index.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { Pool, Client } = require('../../../')
 const http = require('node:http')
 const proxy = require('./proxy')

docs/examples/proxy/websocket.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { Pool, Client } = require('../../../')
 const http = require('node:http')
 const proxy = require('./proxy')

lib/api/abort-signal.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { addAbortListener } = require('../core/util')
 const { RequestAbortedError } = require('../core/errors')
 

lib/api/util.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const assert = require('node:assert')
 const {
   ResponseStatusCodeError

lib/core/symbols.js

@@ -1,3 +1,5 @@
+'use strict'
+
 module.exports = {
   kClose: Symbol('close'),
   kDestroy: Symbol('destroy'),

lib/dispatcher/pool-stats.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { kFree, kConnected, kPending, kQueued, kRunning, kSize } = require('../core/symbols')
 const kPool = Symbol('pool')
 

scripts/generate-pem.js

@@ -1,3 +1,4 @@
+'use strict'
 /* istanbul ignore file */
 
 require('https-pem/install')

scripts/generate-undici-types-package-json.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const fs = require('node:fs')
 const path = require('node:path')
 

scripts/verifyVersion.js

@@ -1,3 +1,5 @@
+'use strict'
+
 /* istanbul ignore file */
 
 const [major, minor, patch] = process.versions.node.split('.').map(v => Number(v))

test/fixtures/fetch.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { createServer } = require('node:http')
 const { fetch } = require('../..')
 

test/fixtures/undici.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { createServer } = require('node:http')
 const { request } = require('../..')
 

test/fixtures/websocket.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { WebSocketServer } = require('ws')
 const { WebSocket } = require('../..')
 

test/jest/mock-scope.test.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const { MockAgent, setGlobalDispatcher, request } = require('../../index')
 
 /* global afterAll, expect, it, AbortController */

test/node-fetch/utils/server.js

@@ -1,3 +1,5 @@
+'use strict'
+
 const http = require('node:http')
 const zlib = require('node:zlib')
 const { once } = require('node:events')