From c06dd965dd36808a94179909fa704c60a5c3f7bf Mon Sep 17 00:00:00 2001
From: Jacob Heun <jacobheun@gmail.com>
Date: Thu, 15 Oct 2020 16:15:15 +0200
Subject: [PATCH] fix: throw when a write occurs on a missing stream

---
 package.json | 3 ++-
 src/mplex.js | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 9927a47..8bcdf77 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,7 @@
   "homepage": "https://github.com/libp2p/js-libp2p-mplex#readme",
   "devDependencies": {
     "aegir": "^27.0.0",
-    "libp2p-interfaces": "^0.6.0",
+    "libp2p-interfaces": "libp2p/js-libp2p-interfaces#feat/streams",
     "p-defer": "^3.0.0",
     "random-bytes": "^1.0.0",
     "random-int": "^2.0.0",
@@ -55,6 +55,7 @@
     "abortable-iterator": "^3.0.0",
     "bl": "^4.0.0",
     "debug": "^4.2.0",
+    "err-code": "^2.0.3",
     "it-pipe": "^1.1.0",
     "it-pushable": "^1.4.0",
     "varint": "^5.0.0"
diff --git a/src/mplex.js b/src/mplex.js
index 22c7320..dc440e7 100644
--- a/src/mplex.js
+++ b/src/mplex.js
@@ -4,6 +4,7 @@ const pipe = require('it-pipe')
 const pushable = require('it-pushable')
 const log = require('debug')('libp2p:mplex')
 const abortable = require('abortable-iterator')
+const errCode = require('err-code')
 const Coder = require('./coder')
 const restrictSize = require('./restrict-size')
 const { MessageTypes, MessageTypeNames } = require('./message-types')
@@ -117,6 +118,9 @@ class Mplex {
     }
     log('new %s stream %s %s', type, id, name)
     const send = msg => {
+      if (!registry.has(id)) {
+        throw errCode(new Error('the stream is not in the muxer registry, it may have already been closed'), 'ERR_STREAM_DOESNT_EXIST')
+      }
       if (log.enabled) {
         log('%s stream %s %s send', type, id, name, { ...msg, type: MessageTypeNames[msg.type], data: msg.data && msg.data.slice() })
       }