models: add required: true to id fields where missing

website/server/models/coupon.js

@@ -11,7 +11,7 @@ import {
 } from '../libs/errors';
 
 export let schema = new mongoose.Schema({
-  _id: {type: String, default: couponCode.generate},
+  _id: {type: String, default: couponCode.generate, required: true},
   event: {type: String, enum: ['wondercon', 'google_6mo']},
   user: {type: String, ref: 'User'},
 }, {

website/server/models/tag.js

@@ -10,6 +10,7 @@ export let schema = new Schema({
     type: String,
     default: uuid,
     validate: [validator.isUUID, 'Invalid uuid.'],
+    required: true,
   },
   name: {type: String, required: true},
   challenge: {type: String},

website/server/models/userNotification.js

@@ -25,6 +25,7 @@ export let schema = new Schema({
     type: String,
     default: uuid,
     validate: [validator.isUUID, 'Invalid uuid.'],
+    required: true,
   },
   type: {type: String, required: true, enum: NOTIFICATION_TYPES},
   data: {type: Schema.Types.Mixed, default: () => {