Discussion for a new feature - allow union to be optional

[sjriccrv]

I have a use case where I'd like to have a query string parameter (type) to be either a string or an array of strings if defined, otherwise allow it to be optional.

I'm pretty new to AdonisJS so if might just be me learning, but I couldn't figure out how to do it without a more complicated approach.

I tried this approach which seems reasonable:

export const getValidator = vine.compile(
  vine.object({
    type: vine.union([vine.string(), vine.array(vine.string())]).optional(),
  })
)

and I got an error that I couldn't use .optional() on a union.

So, I ended up with something like this (which I'm not sure is the best approach though it worked):

const typeString = vine.string().in(['core', 'addon'])
const typeSchema = vine.group([
  vine.group.if((data) => vine.helpers.isMissing(data.type), {}),
  vine.group.else({
    type: vine.unionOfTypes([vine.array(typeString), typeString]),
  }),
])

export const getValidator = vine.compile(vine.object({}).merge(typeSchema))

But then in the controller when I do:

const payload = await request.validateUsing(getValidator)
return await myService.getAll(params.id, payload.type)

I get the typescript error: Property 'type' does not exist on type '{} & {}'.

I would love if .union() would allow .optional() unless there is a better way that I'm not aware of.

Thanks.

[thetutlage]

It will be a nice to have feature. But something I will skip for now and come back to it later (once I have more bandwidth or use-cases)

[sjriccrv]

Understandable.

Thank you for the response and thanks for everything you do with AdonisJS and Vine!

[karimfromjordan]

I just ran into this too. I'm trying to create a schema that looks like this:

const schema = vine.object({
  "rating": vine.unionOfTypes([
    vine.number().min(0).max(5),
    vine.literal("*"),
  ]).optional().nullable(),
})

The rating field should be optional but if it is provided it should be

• a number between 0 and 5
• the literal string of * meaning any rating
• null meaning no rating yet

But unionOfTypes(...) doesn't except literal as a type nor can the field be optional() or nulable().