Why are my inferred type properties optional?

[mallowigi]

I just realized of a big issue using z.infer. I tried with a basic snippet:

const user = z.object({
  username: z.string(),
});
type C = z.infer<typeof user>;

and my type C has the username optional, even though it's not optional.

PS: I have typescript 5.4.5 and use strict: true

[mallowigi]

Oh I found it, it was that property:

"strictNullChecks": false,

that was causing it. Unfortunately for me doing so breaks my whole code.

For people having the same issue...