25 replies

The Use of Undefined with exactOptionalPropertyTypes

Curious what your thoughts are on

undefined

undefined

, given

exactOptionalPropertyTypes

exactOptionalPropertyTypes

.

Historically, I preferred

undefined

undefined

over

null

null

as the default "nil" value, and used

null

null

to signal explicitly "deleting" value, as opposed its absence. Only annoyance there is databases that cast

undefined

undefined

null

null

, so I have to write at least one conversion schema for the database read model.

With

exactOptionalPropertyTypes

exactOptionalPropertyTypes

though, I find that I'm writing even more schema conversions; some tooling spits out explicit

undefined

undefined

s, but over the wire, JSON gets rid of

undefined

undefined

, so values become optional.

I'm not a huge fan of

Option

Option

for record-fields, makes models too complicated, I prefer using

Option

Option

for the entire entity.

For simplicity, I'm leaning towards making everything

null

null

. I guess I could also do

{key?: T | undefined}

{key?: T | undefined}

, and overload it.

How do you deal with nil-values?