Joi: What can be put in the 'is' key of Joi.when(...) ?

[acmoune]

The documentation is not explicit about what we can test in the 'is' key of Joi.when(). How can I say:

1 - IF ref IS 'Hello' OR 'World' OR 'Foo' THEN ...
2 - IF ref IS NOT 'Hello' AND 'World' THEN ...
3 - IF ref IS IN ['HAPI', 'EXPRESS'] THEN ...
4 - IF ref IS NOT IN ['HAPI', 'EXPRESS'] THEN ...
5 - IF ref IS {...} THEN ...

[acmoune]

It would have been easier to understand the doc if there where additional keys like

- IS NOT ... 
- IN [...]
- NOT IN [...]

[Marsup]

Anything that you put in there will be converted to a joi schema for simplicity, but you can provide one directly if you have more advanced needs. The documentation is indeed poor on this point, documentation PRs always welcome.

[acmoune]

OK, please let's take one case.

schema = Joi.object().keys({
    type: Joi.string().valid(['movie', 'documentary', 'advert', 'Clip', 'tv-serie']),
    duration: Joi.number().when('type', {
       is: 'anything-except-tv-serie',
       then: Joi.required()
   })
});

How can I implement 'anything-except-tv-serie' ?

As a work arround I can try this:

{
   is: 'tv-serie',
   otherwise: Joi.required()
}

But I hope there is a better way. What if I want anything except TV-Serie and Movie ?

[Marsup]

Your way works and there's nothing wrong with using only otherwise.
It's translated to :

{ is: Joi.only('tv-serie'), otherwise: Joi.required() }

You could also write it like :

{ is: Joi.not('tv-serie'), then: Joi.required() }

Then more complex cases come naturally as :

{ is: Joi.not(['tv-serie', 'movie']), then: Joi.required() }
// or
{ is: Joi.only(['tv-serie', 'movie']), otherwise: Joi.required() }

Reason about it like any other schema.

[acmoune]

Great, just what I was looking for. I got you now when you said "Anything that you put in there will be converted to a joi schema...".

Thanks.

[Marsup]

I'll keep this one opened in case someone wants to help with the docs.

[acmoune]

OK, sure that docs will help a lot. I will propose something.