square brackets in prehook

Hi, I want to avoid mongoose empty array creation.

mySchema.pre('save', function (next) { [ "item1", "item2", "item3", "item4" ].forEach(function (field) { if (this[field] && isEmpty (this[field])) this[field] = undefined; }); next(); })

I cannot access to the fields using square brackets, how can I generalize this behaviour for multiple items?

[zbjornson]

(Based on your indentation and what I understand of your goal, it looks like you’re missing { } for your if block.)

Looking at the source around that trace, it looks like the replaced value needs to be falsy in order for mongoose to not attempt to emit an event. Does it still fail with undefined?

[vkarpov15]

You can just do new Schema({ arr: { type: [String], default: void 0 } }); to avoid the default empty array creation for arr.