fix: add more strict check for streams in `util.isStream()' (#628)

* fix: add more strict check for streams in `util.isStream()'

* fix: split `isReadable()` & `isWritable()` for more specific checks

* fix: delete was not working to remove `destroy()`

lib/core/request.js

@@ -36,7 +36,7 @@ class Request {
 
     if (body == null) {
       this.body = null
-    } else if (util.isStream(body)) {
+    } else if (util.isReadable(body)) {
       this.body = body
     } else if (util.isBuffer(body)) {
       this.body = body.length ? body : null

lib/core/util.js

@@ -9,8 +9,18 @@ const { InvalidArgumentError } = require('./errors')
 
 function nop () {}
 
-function isStream (body) {
-  return !!(body && typeof body.on === 'function')
+function isReadable (obj) {
+  return !!(obj && typeof obj.pipe === 'function' &&
+    typeof obj.on === 'function')
+}
+
+function isWritable (obj) {
+  return !!(obj && typeof obj.write === 'function' &&
+    typeof obj.on === 'function')
+}
+
+function isStream (obj) {
+  return isReadable(obj) || isWritable(obj)
 }
 
 function parseURL (url) {
@@ -163,6 +173,7 @@ module.exports = {
   getServerName,
   errnoException,
   isStream,
+  isReadable,
   isDestroyed,
   parseHeaders,
   parseKeepAliveTimeout,

test/stream-compat.js

@@ -3,6 +3,7 @@
 const { test } = require('tap')
 const { Client } = require('..')
 const { createServer } = require('http')
+const { Readable } = require('stream')
 const EE = require('events')
 
 test('stream body without destroy', (t) => {
@@ -17,7 +18,8 @@ test('stream body without destroy', (t) => {
     t.teardown(client.destroy.bind(client))
 
     const signal = new EE()
-    const body = new EE()
+    const body = new Readable({ read () {} })
+    body.destroy = undefined
     body.on('error', (err) => {
       t.ok(err)
     })

test/util.js

@@ -0,0 +1,21 @@
+'use strict'
+
+const t = require('tap')
+const { test } = t
+const { Stream } = require('stream')
+const { EventEmitter } = require('events')
+
+const util = require('../lib/core/util')
+
+test('isStream', (t) => {
+  t.plan(3)
+
+  const stream = new Stream()
+  t.ok(util.isStream(stream))
+
+  const buffer = Buffer.alloc(0)
+  t.notOk(util.isStream(buffer))
+
+  const ee = new EventEmitter()
+  t.notOk(util.isStream(ee))
+})