Add a check for changes in study session message before reposting

If people want to have notifications on for the events channel
it might get annoying having the ping go off even if there are no
changes

src/tasks/studySession/channelReminder.js

@@ -29,12 +29,16 @@ export default function sendChannelReminder(client) {
         const mostRecentStudySessionMessage = studySessionMessages.first();
 
         if (isMessageOlderThan5HoursAgo(mostRecentStudySessionMessage)) {
-            mostRecentStudySessionMessage.delete().then(() => {
-                makeStudySessionMessage().then((studyMessage) => {
-                    studySessionChannel.send(studyMessage).catch((error) => {
+            makeStudySessionMessage().then((studyMessage) => {
+                if (upcomingSessionsAreDifferent(mostRecentStudySessionMessage, studyMessage)) {
+                    mostRecentStudySessionMessage.delete().then(() => {
+                        studySessionChannel.send(studyMessage).catch((error) => {
+                            console.log(error);
+                        });
+                    }).catch((error) => {
                         console.log(error);
                     });
-                });
+                }
             }).catch((error) => {
                 console.log(error);
             });
@@ -98,6 +102,21 @@ function getUpcomingStudySessionSummary(message) {
     return truncatedString;
 }
 
+function upcomingSessionsAreDifferent(oldMessage, newMessage) {
+    const oldMessageEmbed = oldMessage.embeds[0];
+    const newMessageEmbed = newMessage.embed;
+    if (oldMessageEmbed.title !== newMessageEmbed.title) {
+        return true;
+    }
+    if (oldMessageEmbed.fields.length !== newMessageEmbed.fields.length) {
+        return true;
+    }
+    return oldMessageEmbed.fields.some((oldMessageEmbedField, index) => {
+        return newMessageEmbed.fields[index].name !== oldMessageEmbedField.name ||
+            newMessageEmbed.fields[index].value !== oldMessageEmbedField.value
+    });
+}
+
 function createNotFoundMessage() {
     return {
         content: upcomingStudySessionMessageContent,