Squashed commit of the following:

commit d03bdee783deff98ee24cc211f1498525bf36c70
Merge: b31ba93233 70f5aa1f55
Author: SabreCat <sabe@habitica.com>
Date:   Mon Dec 18 15:47:29 2023 -0600

    Merge branch 'release' into sabrecat/group-task-fixes

commit b31ba93233
Author: SabreCat <sabe@habitica.com>
Date:   Tue Oct 10 12:02:41 2023 -0500

    fix(groups): missing dot path step
    Also sync assignments on unassign as well as assign

commit 8012f0294d
Author: SabreCat <sabe@habitica.com>
Date:   Tue Oct 10 11:47:59 2023 -0500

    fix(groups): use assigned keys as source of truth

commit 616b1e1486
Author: SabreCat <sabe@habitica.com>
Date:   Tue Oct 10 11:33:28 2023 -0500

    fix(groups): clean up groups to copy tasks
    Fixes #14916

website/server/libs/user/index.js

@@ -147,8 +147,10 @@ export async function update (req, res, { isV3 = false }) {
     await checkNewInputForProfanity(user, res, newBlurb);
   }
 
+  let groupsToMirror;
+  let matchingGroupsArray;
   if (req.body['preferences.tasks.mirrorGroupTasks'] !== undefined) {
-    const groupsToMirror = req.body['preferences.tasks.mirrorGroupTasks'];
+    groupsToMirror = req.body['preferences.tasks.mirrorGroupTasks'];
     if (!Array.isArray(groupsToMirror)) {
       throw new BadRequest('Groups to copy tasks from must be an array.');
     }
@@ -160,7 +162,7 @@ export async function update (req, res, { isV3 = false }) {
       }
     }
 
-    const matchingGroupsCount = await Groups.countDocuments({
+    const matchingGroups = await Groups.find({
       _id: { $in: groupsToMirror },
       'purchased.plan.customerId': { $exists: true },
       $or: [
@@ -168,11 +170,11 @@ export async function update (req, res, { isV3 = false }) {
         { 'purchased.plan.dateTerminated': null },
         { 'purchased.plan.dateTerminated': { $gt: new Date() } },
       ],
+    }, {
+      _id: 1,
     }).exec();
 
-    if (matchingGroupsCount !== groupsToMirror.length) {
-      throw new BadRequest('Groups to copy tasks from must have subscriptions.');
-    }
+    matchingGroupsArray = _.map(matchingGroups, groupRecord => groupRecord._id);
   }
 
   _.each(req.body, (val, key) => {
@@ -234,6 +236,8 @@ export async function update (req, res, { isV3 = false }) {
       if (lastNewsPost) {
         user.flags.lastNewStuffRead = lastNewsPost._id;
       }
+    } else if (key === 'preferences.tasks.mirrorGroupTasks') {
+      user.preferences.tasks.mirrorGroupTasks = _.intersection(groupsToMirror, matchingGroupsArray);
     } else if (acceptablePUTPaths[key]) {
       let adjustedVal = val;
       if (key === 'stats.lvl' && val > common.constants.MAX_LEVEL_HARD_CAP) {

website/server/models/group.js

@@ -1432,11 +1432,6 @@ schema.methods.syncTask = async function groupSyncTask (taskToSync, users, assig
       completed: false,
     };
 
-    if (!taskToSync.group.assignedUsers) {
-      taskToSync.group.assignedUsers = [];
-    }
-    taskToSync.group.assignedUsers.push(user._id);
-
     if (!taskToSync.group.assignedUsersDetail) {
       taskToSync.group.assignedUsersDetail = {};
     }
@@ -1445,6 +1440,8 @@ schema.methods.syncTask = async function groupSyncTask (taskToSync, users, assig
     }
     taskToSync.markModified('group.assignedUsersDetail');
 
+    taskToSync.group.assignedUsers = _.keys(taskToSync.group.assignedUsersDetail);
+
     // Sync tags
     const userTags = user.tags;
     const i = _.findIndex(userTags, { id: group._id });
@@ -1478,8 +1475,7 @@ schema.methods.unlinkTask = async function groupUnlinkTask (
   };
 
   delete unlinkingTask.group.assignedUsersDetail[user._id];
-  const assignedUserIndex = unlinkingTask.group.assignedUsers.indexOf(user._id);
-  unlinkingTask.group.assignedUsers.splice(assignedUserIndex, 1);
+  unlinkingTask.group.assignedUsers = _.keys(unlinkingTask.group.assignedUsersDetail);
   unlinkingTask.markModified('group');
 
   const promises = [unlinkingTask.save()];