From 17ef9ee8293cd6b952ec335b03eb642b6ad9692f Mon Sep 17 00:00:00 2001
From: Jacob Heun <jacobheun@gmail.com>
Date: Tue, 4 Dec 2018 16:59:58 +0100
Subject: [PATCH] fix: conditionally emit errors from muxer (#84)

* fix: conditionally emit errors from muxer
* test: add test for conditional emitter

License: MIT
Signed-off-by: Jacob Heun <jacobheun@gmail.com>
---
 .gitignore         |  1 +
 package.json       |  7 ++++---
 src/muxer.js       | 19 +++++++++++++++++++
 test/muxer.spec.js |  8 ++++++++
 4 files changed, 32 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index f8690b5..9497173 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,7 @@
 **/*.log
 test/repo-tests*
 **/bundle.js
+docs
 
 # Logs
 logs
diff --git a/package.json b/package.json
index 28b30d3..750f1bf 100644
--- a/package.json
+++ b/package.json
@@ -39,14 +39,14 @@
     "npm": ">=3.0.0"
   },
   "devDependencies": {
-    "aegir": "^17.0.1",
+    "aegir": "^17.1.1",
     "chai": "^4.2.0",
     "chai-checkmark": "^1.0.1",
     "dirty-chai": "^2.0.1",
     "interface-stream-muxer": "~0.6.0",
     "libp2p-tcp": "~0.13.0",
     "libp2p-websockets": "~0.12.0",
-    "multiaddr": "^5.0.0",
+    "multiaddr": "^6.0.0",
     "pull-file": "^1.1.0",
     "pull-pair": "^1.1.0",
     "run-parallel": "^1.1.9",
@@ -55,7 +55,8 @@
     "tape": "^4.9.0"
   },
   "dependencies": {
-    "interface-connection": "~0.3.2",
+    "debug": "^4.1.0",
+    "interface-connection": "~0.3.3",
     "pull-catch": "^1.0.0",
     "pull-stream": "^3.6.9",
     "pull-stream-to-stream": "^1.3.4",
diff --git a/src/muxer.js b/src/muxer.js
index bb67af4..fbe233c 100644
--- a/src/muxer.js
+++ b/src/muxer.js
@@ -6,6 +6,9 @@ const toPull = require('stream-to-pull-stream')
 const pullCatch = require('pull-catch')
 const pull = require('pull-stream')
 const noop = () => {}
+const debug = require('debug')
+const log = debug('spdy')
+log.error = debug('spdy:error')
 
 function catchError (stream) {
   return {
@@ -57,6 +60,22 @@ module.exports = class Muxer extends EventEmitter {
     })
   }
 
+  /**
+   * Conditionally emit errors if we have listeners. All other
+   * events are sent to EventEmitter.emit
+   *
+   * @param {string} eventName
+   * @param  {...any} args
+   * @returns {void}
+   */
+  emit (eventName, ...args) {
+    if (eventName === 'error' && !this._events.error) {
+      log.error('error', ...args)
+    } else {
+      super.emit(eventName, ...args)
+    }
+  }
+
   // method added to enable pure stream muxer feeling
   newStream (callback) {
     if (!callback) {
diff --git a/test/muxer.spec.js b/test/muxer.spec.js
index 6bb3929..c94f554 100644
--- a/test/muxer.spec.js
+++ b/test/muxer.spec.js
@@ -100,4 +100,12 @@ describe('multiplex-muxer', () => {
       code: 'ERR_UNKNOWN'
     }))
   })
+
+  it('should not throw if there are no error listeners', () => {
+    muxer.removeAllListeners('error')
+
+    muxer.spdy.emit('error', Object.assign(new Error('bad things'), {
+      code: 'ERR_UNKNOWN'
+    }))
+  })
 })