From cbd9ff2dd90a34e9afca9b595565955c030006ff Mon Sep 17 00:00:00 2001
From: Tom Moor <tom.moor@gmail.com>
Date: Sat, 7 Dec 2019 11:40:15 -0800
Subject: [PATCH] =?UTF-8?q?fixes=20#1093=20=E2=80=93=20account=20for=20no?=
 =?UTF-8?q?=20previous=20revision=20in=20backlinks=20service?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 server/services/backlinks.js     | 6 ++++--
 shared/utils/parseDocumentIds.js | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/server/services/backlinks.js b/server/services/backlinks.js
index 0c127171..2502dd9c 100644
--- a/server/services/backlinks.js
+++ b/server/services/backlinks.js
@@ -38,12 +38,14 @@ export default class Backlinks {
         const document = await Document.findByPk(event.documentId);
         if (!document.publishedAt) return;
 
-        const [currentRevision, previsionRevision] = await Revision.findAll({
+        const [currentRevision, previousRevision] = await Revision.findAll({
           where: { documentId: event.documentId },
           order: [['createdAt', 'desc']],
           limit: 2,
         });
-        const previousLinkIds = parseDocumentIds(previsionRevision.text);
+        const previousLinkIds = previousRevision
+          ? parseDocumentIds(previousRevision.text)
+          : [];
         const currentLinkIds = parseDocumentIds(currentRevision.text);
         const addedLinkIds = difference(currentLinkIds, previousLinkIds);
         const removedLinkIds = difference(previousLinkIds, currentLinkIds);
diff --git a/shared/utils/parseDocumentIds.js b/shared/utils/parseDocumentIds.js
index 7dc466ac..68c08dec 100644
--- a/shared/utils/parseDocumentIds.js
+++ b/shared/utils/parseDocumentIds.js
@@ -2,7 +2,7 @@
 import MarkdownSerializer from 'slate-md-serializer';
 const Markdown = new MarkdownSerializer();
 
-export default function parseDocumentIds(text: string) {
+export default function parseDocumentIds(text: string): string[] {
   const value = Markdown.deserialize(text);
   let links = [];