feat: replace debug module with pure node:util::debuglog (#1885)

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- [x] I have rebased all commits where necessary so that reviewing this
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along with context if necessary.

Author: 3imed-jaberi

docs/guide.md

@@ -213,13 +213,13 @@ app.use(async function (ctx, next) {
 
 ## Debugging Koa
 
-  Koa along with many of the libraries it's built with support the __DEBUG__ environment variable from [debug](https://github.com/visionmedia/debug) which provides simple conditional logging.
+  Koa, along with many of the libraries it's built, can be debugged using Node.js's built-in util.debuglog, which provides simple conditional logging via the __NODE_DEBUG__ environment variable.
 
   For example
-  to see all Koa-specific debugging information just pass `DEBUG=koa*` and upon boot you'll see the list of middleware used, among other things.
+  to see all Koa-specific debugging information just pass `NODE_DEBUG=koa*` and upon boot you'll see the list of middleware used, among other things.
 
 ```
-$ DEBUG=koa* node --harmony examples/simple
+$ NODE_DEBUG=koa* node --harmony examples/simple
   koa:application use responseTime +0ms
   koa:application use logger +4ms
   koa:application use contentLength +0ms
@@ -234,7 +234,7 @@ $ DEBUG=koa* node --harmony examples/simple
   For example:
 
 ```js
-const path = require('path');
+const path = require('node:path');
 const serve = require('koa-static');
 
 const publicFiles = serve(path.join(__dirname, 'public'));
@@ -249,6 +249,8 @@ app.use(publicFiles);
   koa:application use static /public +0ms
 ```
 
+This lets you use Koa’s internal debug logs without any third-party dependencies by relying on node:util's built-in debuglog.
+
 ## HTTP2
 
 Example of setting up an HTTP2 server with Koa using the HTTP compatibility layer:

lib/application.js

@@ -3,22 +3,23 @@
 /**
  * Module dependencies.
  */
+const util = require('node:util')
+const debug = util.debuglog('koa:application')
+const Emitter = require('node:events')
+const Stream = require('node:stream')
+const http = require('node:http')
+const { AsyncLocalStorage } = require('node:async_hooks')
 
-const debug = require('debug')('koa:application')
 const onFinished = require('on-finished')
-const response = require('./response')
 const compose = require('koa-compose')
-const context = require('./context')
-const request = require('./request')
 const statuses = require('statuses')
-const Emitter = require('events')
-const util = require('util')
-const Stream = require('stream')
-const http = require('http')
+const { HttpError } = require('http-errors')
+
+const request = require('./request')
+const response = require('./response')
+const context = require('./context')
 const isStream = require('./is-stream.js')
 const only = require('./only.js')
-const { HttpError } = require('http-errors')
-const { AsyncLocalStorage } = require('async_hooks')
 
 /** @typedef {typeof import ('./context') & {
  *  app: Application
@@ -47,18 +48,18 @@ module.exports = class Application extends Emitter {
    */
 
   /**
-    *
-    * @param {object} [options] Application options
-    * @param {string} [options.env='development'] Environment
-    * @param {string[]} [options.keys] Signed cookie keys
-    * @param {boolean} [options.proxy] Trust proxy headers
-    * @param {number} [options.subdomainOffset] Subdomain offset
-    * @param {string} [options.proxyIpHeader] Proxy IP header, defaults to X-Forwarded-For
-    * @param {number} [options.maxIpsCount] Max IPs read from proxy IP header, default to 0 (means infinity)
-    * @param {function} [options.compose] Function to handle middleware composition
-    * @param {boolean} [options.asyncLocalStorage] Enable AsyncLocalStorage, default to false
-    *
-    */
+   *
+   * @param {object} [options] Application options
+   * @param {string} [options.env='development'] Environment
+   * @param {string[]} [options.keys] Signed cookie keys
+   * @param {boolean} [options.proxy] Trust proxy headers
+   * @param {number} [options.subdomainOffset] Subdomain offset
+   * @param {string} [options.proxyIpHeader] Proxy IP header, defaults to X-Forwarded-For
+   * @param {number} [options.maxIpsCount] Max IPs read from proxy IP header, default to 0 (means infinity)
+   * @param {function} [options.compose] Function to handle middleware composition
+   * @param {boolean} [options.asyncLocalStorage] Enable AsyncLocalStorage, default to false
+   *
+   */
 
   constructor (options) {
     super()
@@ -113,11 +114,7 @@ module.exports = class Application extends Emitter {
    */
 
   toJSON () {
-    return only(this, [
-      'subdomainOffset',
-      'proxy',
-      'env'
-    ])
+    return only(this, ['subdomainOffset', 'proxy', 'env'])
   }
 
   /**
@@ -142,7 +139,7 @@ module.exports = class Application extends Emitter {
    */
 
   use (fn) {
-    if (typeof fn !== 'function') throw new TypeError('middleware must be a function!')
+    if (typeof fn !== 'function') { throw new TypeError('middleware must be a function!') }
     debug('use %s', fn._name || fn.name || '-')
     this.middleware.push(fn)
     return this
@@ -190,7 +187,7 @@ module.exports = class Application extends Emitter {
   handleRequest (ctx, fnMiddleware) {
     const res = ctx.res
     res.statusCode = 404
-    const onerror = err => ctx.onerror(err)
+    const onerror = (err) => ctx.onerror(err)
     const handleResponse = () => respond(ctx)
     onFinished(res, onerror)
     return fnMiddleware(ctx).then(handleResponse).catch(onerror)
@@ -206,9 +203,9 @@ module.exports = class Application extends Emitter {
     /** @type {Context} */
     const context = Object.create(this.context)
     /** @type {KoaRequest} */
-    const request = context.request = Object.create(this.request)
+    const request = (context.request = Object.create(this.request))
     /** @type {KoaResponse} */
-    const response = context.response = Object.create(this.response)
+    const response = (context.response = Object.create(this.response))
     context.app = request.app = response.app = this
     context.req = request.req = response.req = req
     context.res = request.res = response.res = res
@@ -234,7 +231,7 @@ module.exports = class Application extends Emitter {
     const isNativeError =
       Object.prototype.toString.call(err) === '[object Error]' ||
       err instanceof Error
-    if (!isNativeError) throw new TypeError(util.format('non-error thrown: %j', err))
+    if (!isNativeError) { throw new TypeError(util.format('non-error thrown: %j', err)) }
 
     if (err.status === 404 || err.expose) return
     if (this.silent) return
@@ -307,9 +304,9 @@ function respond (ctx) {
 
   if (Buffer.isBuffer(body)) return res.end(body)
   if (typeof body === 'string') return res.end(body)
-  if (body instanceof Blob) return Stream.Readable.from(body.stream()).pipe(res)
-  if (body instanceof ReadableStream) return Stream.Readable.from(body).pipe(res)
-  if (body instanceof Response) return Stream.Readable.from(body?.body || '').pipe(res)
+  if (body instanceof Blob) { return Stream.Readable.from(body.stream()).pipe(res) }
+  if (body instanceof ReadableStream) { return Stream.Readable.from(body).pipe(res) }
+  if (body instanceof Response) { return Stream.Readable.from(body?.body || '').pipe(res) }
   if (isStream(body)) return body.pipe(res)
 
   // body: json

package-lock.json

@@ -35,32 +35,31 @@
   ],
   "license": "MIT",
   "dependencies": {
-    "accepts": "^1.3.5",
+    "accepts": "^1.3.8",
     "cache-content-type": "^1.0.0",
-    "content-disposition": "~0.5.2",
-    "content-type": "^1.0.4",
+    "content-disposition": "~0.5.4",
+    "content-type": "^1.0.5",
     "cookies": "~0.9.1",
-    "debug": "^4.3.2",
     "delegates": "^1.0.0",
-    "destroy": "^1.0.4",
+    "destroy": "^1.2.0",
     "encodeurl": "^2.0.0",
     "escape-html": "^1.0.3",
     "fresh": "~0.5.2",
-    "http-assert": "^1.3.0",
+    "http-assert": "^1.5.0",
     "http-errors": "^2.0.0",
     "koa-compose": "^4.1.0",
-    "on-finished": "^2.3.0",
-    "parseurl": "^1.3.2",
+    "on-finished": "^2.4.1",
+    "parseurl": "^1.3.3",
     "statuses": "^2.0.1",
     "type-is": "^2.0.1",
     "vary": "^1.1.2"
   },
   "devDependencies": {
     "c8": "^10.1.3",
-    "gen-esm-wrapper": "^1.0.6",
+    "gen-esm-wrapper": "^1.1.3",
     "snazzy": "^9.0.0",
-    "standard": "^17.1.0",
-    "supertest": "^7.0.0"
+    "standard": "^17.1.2",
+    "supertest": "^7.1.1"
   },
   "engines": {
     "node": ">= 18"