chore: apply suggestions from code review

Co-Authored-By: Jacob Heun <jacobheun@gmail.com>

src/get-peer.js

@@ -0,0 +1,40 @@
+'use strict'
+
+const PeerId = require('peer-id')
+const multiaddr = require('multiaddr')
+const errCode = require('err-code')
+
+const { codes } = require('./errors')
+
+/**
+ * Converts the given `peer` to a `Peer` object.
+ * If a multiaddr is received, the addressBook is updated.
+ * @param {PeerId|Multiaddr|string} peer
+ * @param {PeerStore} peerStore
+ * @returns {{ id: PeerId, multiaddrs: Array<Multiaddr> }}
+ */
+function getPeer (peer) {
+  if (typeof peer === 'string') {
+    peer = multiaddr(peer)
+  }
+
+  let addr
+  if (multiaddr.isMultiaddr(peer)) {
+    addr = peer
+    try {
+      peer = PeerId.createFromB58String(peer.getPeerId())
+    } catch (err) {
+      throw errCode(
+        new Error(`${peer} is not a valid peer type`),
+        codes.ERR_INVALID_MULTIADDR
+      )
+    }
+  }
+
+  return {
+    id: peer,
+    multiaddrs: addr ? [addr] : undefined
+  }
+}
+
+module.exports = getPeer