Missing optional Array params default to the Hash instead of Array

[adamcooper]

If if declare a param as a type: Array with nested params

params do
  optional :comments, type: Array do
    optional :description, type: String
  end
end
post do
  { params: params.slice(:comments), declared: declared(params) }
end

and it is missing from the incoming params (or has a default of nil) then it defaults to a Hash

curl -X POST http://localhost:9292/api/entities  -d '{}' -H "Content-Type: application/json"

{"params":{},"declared":{"comments":{"description":null}}}

This only occurs on the optional as the group and requires both throw validation errors.

There is a workaround by setting a default: [] on the Array param.

[dblock]

This is an interesting one. I think it's a legit bug. Would love at least a spec that reproduces it.

[adamcooper]

@dblock - I opened a PR w/ two specs for Arrays and Hashes.

I wonder if the required params inside optional groups issue (#723) is related.

[dm1try]

There are two different issues here.

The first,

def slice(*keys) # If the given keys don't exist, returns an empty hash.

so { params: params.slice(:missing_param) } =>"{"params":{}}" is expected behaviour

the second one, declared has include_missing option(by default is true)
so your specs from #895 are passed if include_missing: false is used.

@adamcooper take a look :)

[adamcooper]

@dm1try - Thanks for the response.

I just included the first slice to prove that nothing was actually in the params.

I wrote the specs to possibly simplify the implementation.

The issue is the default value (with include_missing = true) for nested arrays comes back as a hash instead of an array. That seems like a bug to me.

I updated the specs in this commit to help show the issue.

[dm1try]

@adamcooper,

I just included the first slice to prove that nothing was actually in the params.

why just not params[:comments]?)

The issue is the default value (with include_missing = true) for nested arrays comes back as a hash instead of an array. That seems like a bug to me.

Anyway, it's definitely a bug. I see now.

I updated the specs in this commit to help show the issue.

Thanks, now it is better than it was and makes sense!

[adamcooper]

@dm1try - I can't remember exactly why I used slice instead of the simpler params[:comments]. I think I was trying different combinations of multiple parameters so slice(:array, :hash) was simpler in one line rather than array: params[:array], hash: params[:hash]. hehe.

Thanks! Please let me know if I can help out. I spent some time reading through the source when I was using Grape and Grape Swagger - trying to understand how to use them together really. I'm not super familiar but would like to help out if I can.

I originally ran into something like this issue #928. I also was trying to use nested require(s/d) validations inside an optional array validation.

[u2]

See #994.It can be closed, I think.

[dblock]

Closing, @adamcooper please confirm.