From ed2dbd9beafefa03a9ada3ce0f4a95b14266fc07 Mon Sep 17 00:00:00 2001
From: achingbrain <alex@achingbrain.net>
Date: Mon, 20 Jul 2020 10:51:29 +0100
Subject: [PATCH] fix: return empty array when no multiaddrs are known

Returning `undefined` makes the address length check in [dialler/index.js](https://github.com/libp2p/js-libp2p/blob/master/src/dialer/index.js#L73-L75)
fail with `cannot read property length of undefined` so the change
here is to always return an array, but it might be empty if we don't
know any multiaddrs for the given peer.
---
 src/peer-store/address-book.js       | 2 +-
 test/peer-store/address-book.spec.js | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/peer-store/address-book.js b/src/peer-store/address-book.js
index 7841a320..2112b370 100644
--- a/src/peer-store/address-book.js
+++ b/src/peer-store/address-book.js
@@ -179,7 +179,7 @@ class AddressBook extends Book {
     const record = this.data.get(peerId.toB58String())
 
     if (!record) {
-      return undefined
+      return []
     }
 
     return record.map((address) => {
diff --git a/test/peer-store/address-book.spec.js b/test/peer-store/address-book.spec.js
index d14923f5..638cb9a0 100644
--- a/test/peer-store/address-book.spec.js
+++ b/test/peer-store/address-book.spec.js
@@ -323,10 +323,10 @@ describe('addressBook', () => {
       throw new Error('invalid peerId should throw error')
     })
 
-    it('returns undefined if no multiaddrs are known for the provided peer', () => {
+    it('returns empty array if no multiaddrs are known for the provided peer', () => {
       const addresses = ab.getMultiaddrsForPeer(peerId)
 
-      expect(addresses).to.not.exist()
+      expect(addresses).to.be.empty()
     })
 
     it('returns the multiaddrs stored', () => {