Type Coercion With Lambda In Values?

[jonmchan]

I'm trying to combine type coercion with lambda in values validation such as:

requires :type, type: Integer, values: { except: -> { [ 3, 4, 5 ] } } # real implementation would be dynamic call

I get however this error:

/Users/jonathan/code/libs/grape/lib/grape/validations/params_scope.rb:358:in `validate_value_coercion': type: Integer is incompatible with values: {:except=>#<Proc:0x007fa873aabbf8@/Users/jonathan/code/libs/grape/spec/grape/validations/validators/values_spec.rb:150 (lambda)>} (Grape::Exceptions::IncompatibleOptionValues)

Is there a way to use lambda for validation with type coercion? I know we can't validate beforehand that the lambda expression is going to be proper values... but I would still like the parameter passed to be casted into an Integer.

[dblock]

I think you should be able to. I say write a spec that reproduces what you want.

[jonmchan]

Here is your failing tests:

  context 'exclusive excepts with lambda and coercion' do
    it 'allows any other value outside excepts' do
      get '/except/exclusive/lambda/coercion', type: 'value'
      expect(last_response.status).to eq 200
      expect(last_response.body).to eq({ type: 'value' }.to_json)
    end

    it 'rejects values that matches except' do
      get '/except/exclusive/lambda/coercion', type: 'invalid-type1'
      expect(last_response.status).to eq 400
      expect(last_response.body).to eq({ error: 'type has a value not allowed' }.to_json)
    end
end

https://github.com/jonmchan/grape/blob/lambda_values_and_coercion/spec/grape/validations/validators/values_spec.rb#L437

It fails fast and hard not even allowing rspec to be run. It fails during the time that it is reading in the API definition I believe.

[dblock]

Thanks. Marked as confirmed bug. Now that you have a test you should try to fix it!

[jonmchan]

Opensource projects.... how you so quickly suck me into contributing... ;-)

Anyways, it looks simple enough to fix. I'm going to make it so that if except or value is a proc, the api definition validation will be skipped.

[dblock]

We love you @jonmchan. Really.

[jonmchan]

#1493 fixes this.