Optimize database access for some use cases (#15444)

* optimize query when listing challenge tasks

* Optimize query for checking if user is party leader

website/server/controllers/api-v3/groups.js

@@ -1316,13 +1316,13 @@ api.getLookingForParty = {
     const PAGE = req.query.page || 0;
     const PAGE_START = USERS_PER_PAGE * PAGE;
 
-    const partyLed = await Group
-      .findOne({
-        type: 'party',
-        leader: user._id,
-      })
-      .select('_id')
-      .exec();
+    let partyLed = false;
+    if (user.party._id) {
+      const party = await Group.getGroup({ user, groupId: user.party._id });
+      if (party && party.leader === user._id) {
+        partyLed = true;
+      }
+    }
 
     if (!partyLed) {
       throw new BadRequest(apiError('notPartyLeader'));

website/server/libs/tasks/index.js

@@ -233,7 +233,7 @@ async function getTasks (req, res, options = {}) {
     } else {
       query.type = type.slice(0, -1); // removing the final "s"
     }
-  } else {
+  } else if (!challenge) {
     query.$and = [{
       $or: [ // Exclude completed todos
         { type: 'todo', completed: false },