Make it possible to configure new Hash constructor type

[Kukunin]

Currently Types::Hash has 6 pre-defined constructor types, with own properties.

But they aren't enough for all purposes, e.g. there is an issue dry-rb/dry-struct#32 for dry-struct (created by me).

Now, I've got another case, where I want hash to allow defined keys absence, but deny any extra keys.

Instead of defining new 7th constructor type with confusing name, maybe it's good to configure contructor types alone?

Something like:

SpecialHash = Types::Hash.build_constructor(
  accept_invalid_types: false, 
  allow_value_absence: true, 
  allow_extra_keys: false
)
MyType = SpecialHash.schema(name: Types::String, age: Types::Coercible::Int)

[solnic]

We're definitely not going to add more hash schema types, or an API for configuring them, especially if it's related to validating input, as data validation is meant to by handled by dry-validation. Schema types that we have were added to cover a couple, very specific use-cases, that are related to building structs using data from specific sources (like a database, or JSON).

From what I've seen, people keep asking about more relaxed approach to setting defaults, and it's always related to testing, it seems like that's your situation as well, right?

[Kukunin]

In my case it is a need in Domain layer.

I have an Value Object to represent answers on pre-defined questions. There are 12 of such questions. All answers are optional. All answers are true/false.

So I decided, that Hash with question => answer works here.

I don't want an array of question, because there may be duplicates, and it's more complicated.
I don't want to make API client to enumerate all 12 questions explicitly, if there is only 1 answer available (so, no strict and permissive constructor).
I don't want to allow any unexpected answer to be present in the hash (so, no schema constructor)
Because there is HUGE difference between nil and false value for answer, I don't want to keep questions without answers in that hash (so, no dry_struct)

Currently, the most representative way is Types::Hash.schema with custom predicate to deny unexpected keys.

BTW, feel free to close this issue

[Kukunin]

btw, #113 would work here as well

Hash.keys(Types::Strict::Symbol.constrained(included_in: [whitelist]))

[flash-gordon]

We implemented support for flexible yet simple schemas. #113 remains open for now but I have a feeling we'll implement it as well before 1.0 is out.