Fix validation error for nested array when requires => optional =…

…> `requires`

This bug is due to the params parsing code return `{}` when the value is not found.
This is fine in most cases, however in the instance that the value was optional
and has nested required values.

I was not able to find a way to confind the changes to just the parameter parsing
as this resulted in the indexing being incorrect if any of the other array objects
had an error.

I have used a class to indicate that an Optional Value was missing as this avoid issues
with the value actually being in the response.

CHANGELOG.md

@@ -7,6 +7,7 @@
 #### Fixes
 
 * Your contribution here.
+* : Fix validation error when Required Array nested inside an optional array - [@dwhenry](https://github/dwhenry).
 * [#2127](https://github.com/ruby-grape/grape/pull/2127): Fix a performance issue with dependent params - [@dnesteryuk](https://github.com/dnesteryuk).
 * [#2126](https://github.com/ruby-grape/grape/pull/2126): Fix warnings about redefined attribute accessors in `AttributeTranslator` - [@samsonjs](https://github.com/samsonjs).
 * [#2121](https://github.com/ruby-grape/grape/pull/2121): Fix 2.7 deprecation warning in validator_factory - [@Legogris](https://github.com/Legogris).

lib/grape/dsl/parameters.rb

@@ -227,13 +227,17 @@ def declared_param?(param)
 
  alias group requires
 
- def map_params(params, element)
+ class EmptyOptionalValue; end
+
+ def map_params(params, element, is_array = false)
  if params.is_a?(Array)
  params.map do |el|
- map_params(el, element)
+ map_params(el, element, true)
  end
  elsif params.is_a?(Hash)
- params[element] || {}
+ params[element] || (@optional && is_array ? EmptyOptionalValue : {})
+ elsif params == EmptyOptionalValue
+ EmptyOptionalValue
  else
  {}
  end

lib/grape/validations/single_attribute_iterator.rb

@@ -7,10 +7,20 @@ class SingleAttributeIterator < AttributesIterator
 
  def yield_attributes(val, attrs)
  attrs.each do |attr_name|
- yield val, attr_name, empty?(val)
+ yield val, attr_name, empty?(val), skip?(val)
  end
  end
 
+
+ # This is a special case so that we can ignore tree's where option
+ # values are missing lower down. Unfortunately we can remove this
+ # are the parameter parsing stage as they are required to ensure
+ # the correct indexing is maintained
+ def skip?(val)
+ # return false
+ val == Grape::DSL::Parameters::EmptyOptionalValue
+ end
+
  # Primitives like Integers and Booleans don't respond to +empty?+.
  # It could be possible to use +blank?+ instead, but
  #

lib/grape/validations/validators/base.rb

@@ -43,7 +43,8 @@ def validate!(params)
  # there may be more than one error per field
  array_errors = []
 
- attributes.each do |val, attr_name, empty_val|
+ attributes.each do |val, attr_name, empty_val, skip_value|
+ next if skip_value
  next if !@scope.required? && empty_val
  next unless @scope.meets_dependency?(val, params)
  begin

spec/grape/validations_spec.rb

@@ -883,6 +883,34 @@ def validate_param!(attr_name, params)
  end
  expect(declared_params).to eq([items: [:key, { optional_subitems: [:value] }, { required_subitems: [:value] }]])
  end
+
+ it "does not report errors when required array inside missing optional array" do
+ subject.params do
+ requires :orders, type: Array do
+ requires :id, type: Integer
+ optional :drugs, type: Array do
+ requires :batches, type: Array do
+ requires :batch_no, type: String
+ end
+ end
+ end
+ end
+
+ subject.get '/validate_required_arrays_under_optional_arrays' do
+ 'validate_required_arrays_under_optional_arrays works!'
+ end
+
+ data = {
+ orders: [
+ { id: 77, drugs: [{batches: [{batch_no: "A1234567"}]}]},
+ { id: 70 }
+ ]
+ }
+
+ get '/validate_required_arrays_under_optional_arrays', data
+ expect(last_response.body).to eq("validate_required_arrays_under_optional_arrays works!")
+ expect(last_response.status).to eq(200)
+ end
  end
 
  context 'multiple validation errors' do