Find coerce_type for Array when not specified

CHANGELOG.md

@@ -16,6 +16,7 @@
 * [#821](https://github.com/intridea/grape/pull/821): Fixed passing string value when hash is expected in params - [@rebelact](https://github.com/rebelact).
 * [#824](https://github.com/intridea/grape/pull/824): Validate array params against list of acceptable values - [@dnd](https://github.com/dnd).
 * [#813](https://github.com/intridea/grape/pull/813): Routing methods dsl refactored to get rid of explicit `paths` parameter - [@AlexYankee](https://github.com/AlexYankee).
+* [#826](https://github.com/intridea/grape/pull/826): Find coerce_type for Array when not specified - [@manovotn](https://github.com/manovotn).
 * Your contribution here.
 
 0.9.0 (8/27/2014)

lib/grape/validations/params_scope.rb

@@ -97,6 +97,7 @@ def validates(attrs, validations)
  validations[:coerce] = validations.delete(:type) if validations.key?(:type)
 
  coerce_type = validations[:coerce]
+
  doc_attrs[:type] = coerce_type.to_s if coerce_type
 
  desc = validations.delete(:desc) || validations.delete(:description)
@@ -112,6 +113,8 @@ def validates(attrs, validations)
 
  values = values.call if values.is_a?(Proc)
 
+ coerce_type = values.first.class if values && coerce_type == Array && !values.empty?
+
  # default value should be present in values array, if both exist
  if default && values && !values.include?(default)
  raise Grape::Exceptions::IncompatibleOptionValues.new(:default, default, :values, values)

spec/grape/validations/params_scope_spec.rb

@@ -24,4 +24,35 @@ def app
  end
  end
  end
+
+ context 'array without coerce type explicitly given' do
+
+ it 'sets the type based on first element' do
+ subject.params do
+ requires :periods, type: Array, values: -> { ['day', 'month'] }
+ end
+ subject.get('/required') { 'required works' }
+
+ get '/required', periods: ['day', 'month']
+ expect(last_response.status).to eq(200)
+ expect(last_response.body).to eq('required works')
+ end
+
+ it 'fails to call API without Array type' do
+ subject.params do
+ requires :periods, type: Array, values: -> { ['day', 'month'] }
+ end
+ subject.get('/required') { 'required works' }
+
+ get '/required', periods: 'day'
+ expect(last_response.status).to eq(400)
+ expect(last_response.body).to eq('periods is invalid')
+ end
+
+ it 'raises exception when values are of different type' do
+ expect {
+ subject.params { requires :numbers, type: Array, values: -> { [1, "definitely not a number", 3] } }
+ }.to raise_error Grape::Exceptions::IncompatibleOptionValues
+ end
+ end
 end