refactor!: replace is-promise dependency with instanceof check

BREAKING: drops support for non-native promises

Closes #136

Signed-off-by: Jon Koops <jonkoops@gmail.com>

Author: jonkoops

HISTORY.md

@@ -4,6 +4,11 @@ unreleased
 * Remove `setImmediate` support check
 * Restore `debug` dependency
 
+3.0.0 / ????-??-??
+==================
+
+* Replace `is-promise` dependency with `instanceof` check (drops support for non-native promises)
+
 2.1.0 / 2025-02-10
 ==================
 

index.js

@@ -12,7 +12,6 @@
  * @private
  */
 
-const isPromise = require('is-promise')
 const Layer = require('./lib/layer')
 const { METHODS } = require('node:http')
 const parseUrl = require('parseurl')
@@ -646,7 +645,7 @@ function processParams (params, layer, called, req, res, done) {
 
     try {
       const ret = fn(req, res, paramCallback, paramVal, key)
-      if (isPromise(ret)) {
+      if (ret instanceof Promise) {
         ret.then(null, function (error) {
           paramCallback(error || new Error('Rejected promise'))
         })

lib/layer.js

@@ -12,7 +12,6 @@
  * @private
  */
 
-const isPromise = require('is-promise')
 const pathRegexp = require('path-to-regexp')
 const debug = require('debug')('router:layer')
 
@@ -115,7 +114,7 @@ Layer.prototype.handleError = function handleError (error, req, res, next) {
     const ret = fn(error, req, res, next)
 
     // wait for returned promise
-    if (isPromise(ret)) {
+    if (ret instanceof Promise) {
       ret.then(null, function (error) {
         next(error || new Error('Rejected promise'))
       })
@@ -147,7 +146,7 @@ Layer.prototype.handleRequest = function handleRequest (req, res, next) {
     const ret = fn(req, res, next)
 
     // wait for returned promise
-    if (isPromise(ret)) {
+    if (ret instanceof Promise) {
       ret.then(null, function (error) {
         next(error || new Error('Rejected promise'))
       })

package.json

@@ -10,7 +10,6 @@
   "repository": "pillarjs/router",
   "dependencies": {
     "debug": "^4.4.0",
-    "is-promise": "^4.0.0",
     "parseurl": "^1.3.3",
     "path-to-regexp": "^8.0.0"
   },