Group param with a required param defaults to Array

[jdp]

I'm trying to use a required param inside of a group, like this:

params do
  group :a do
    requires :b
  end
end

As an aside, my actual use case looks more like:

params do
  group :a do
    requires :b
  end
  group :c do
    requires :d
  end
  exactly_one_of :a, :c
end

But if I send a request that should satisfy that first example, like one of these:

$ curl "localhost:9292/case" -d "a[b]=c"
$ curl "localhost:9292/case" -d '{"a":{"b":"c"}}' -H "Content-Type: application/json"

I get a response saying a is invalid:

{"error":"a is invalid"}

I made an example here that reproduces the bug. I'm using grape version 0.8.0.

[dm1try]

Hello, seems like you should provide Hash type for your groups.

group :a, type: Hash do
  requires :b
end

from readme:
... With a block, group, requires and optional accept an additional option type which can be either Array or Hash, and defaults to Array...

BTW, I'd like Hash as default value ;)

[dblock]

Lets not change the default, but I would be open to raising an error when the type is not provided in this case.

[jrichter1]

I'm going to give it a shot to make it raise an error if no type is specified. I'll issue a PR when done and we'll see what comes out of it.

[dnesteryuk]

The solution was implemented in the attached PR.