literals should accept null

[KristjanTammekivi]

Feature Request

https://typia.io/playground/?script=JYWwDg9gTgLgBDAnmYBDOAzKERwERIqp4DcAUGYWgHQA2wMAplKrQM4A8A5AIJdwAfOADsArrVoA+ABQBKIA

Currently null does not work, the extends for literals does not allow for it and when suppressing the error it just omits the value from the array

[samchon]

I think that null cannot be distinguished as constant literal value of atomic values.

In JS classification, null is a type of object. Therefore, current typia supports only those types in literals function.

• boolean
• number
• bigint
• string

[KristjanTammekivi]

I don't quite see how that affects it, I managed to add a few lines of code into literalsProgrammer to get nulls to work

I'd happily take a closer look at the original code but I can't seem to get the tests to work

A bit off topic: I wanted to add a github action step to check that the test:generate has been run, seemed to notify just fine, but after running test:generate the tests don't seem to pass https://github.com/KristjanTammekivi/typia/actions/runs/5414154249/jobs/9840790293

[samchon]

You can just check nullable through Metadata.nullable property in the LiteralsProgrammer.

Also, you have to change generic type of literals function to like below:

export function literals<T extends Atomic.Type | null>(): T[];