Delete nested object with mongoose

Question

I got this mongoose schemas:

const UserSchema = new Schema({
  email: {
    type: String,
    required: true,
    unique: true,
  },
  groups: [
    {
      groupName: {
        type: String,
        required: true,
      },
      groupMembers: [{ type: Schema.Types.ObjectId, ref: "GroupMember" }],
    },
  ],
});


const GroupMemberSchema = new Schema({
    firstName: String,
    lastName: String,
    birthday: Date,
    gender: String,
    age: Number
});

I want to have 2 routes:

• Delete a group member from the groupMembers array based on objectId.
• Delete a whole group from the groups array based on objectId.

My attempt for the delete group member route. This route removes the group member from the groupMembers collection succesfully, but the group member still exist in the user collection:

router.delete(
  "/:userId/:groupId/:groupMemberId",
  catchAsync(async (req, res) => {
    const { userId, groupId, groupMemberId } = req.params;
    await GroupMember.findByIdAndDelete(groupMemberId);
    const user = await User.findById(userId);
    const group = user.groups.find((group) => group._id.toString() === groupId);
    const groupIndex = user.groups.indexOf(group);
    const updatedGroupmembers = user.groups[groupIndex].groupMembers.filter(groupMember=> groupMember._id.toString()!==groupMemberId);
    res.send({updatedGroupmembers})
  })
);

Answer 1

Did you try using $pull?

router.delete(
  '/:userId/:groupId/:groupMemberId',
  catchAsync(async (req, res) => {
    const { userId, groupId, groupMemberId } = req.params;
    await GroupMember.findByIdAndDelete(groupMemberId);
    const updatedUser = await User.findByIdAndUpdate({ id: userId }, { $pull: { groups: groupId } }, { new: true });
    res.send({ updatedUser });
  }),
);