Merge pull request #1962 from dblock/reapply-1961

Re-apply the micro-optimizations and parent fix from #1961.

Author: dm1try

lib/grape/dsl/settings.rb

@@ -171,7 +171,11 @@ def within_namespace(&_block)
       # the superclass's :inheritable_setting.
       def build_top_level_setting
         Grape::Util::InheritableSetting.new.tap do |setting|
-          if defined?(superclass) && superclass.respond_to?(:inheritable_setting) && superclass != Grape::API
+          # Doesn't try to inherit settings from +Grape::API::Instance+ which also responds to
+          # +inheritable_setting+, however, it doesn't contain any user-defined settings.
+          # Otherwise, it would lead to an extra instance of +Grape::Util::InheritableSetting+
+          # in the chain for every endpoint.
+          if defined?(superclass) && superclass.respond_to?(:inheritable_setting) && superclass != Grape::API::Instance
             setting.inherit_from superclass.inheritable_setting
           end
         end

lib/grape/util/stackable_values.rb

@@ -13,6 +13,7 @@ def initialize(*_args)
         @frozen_values = {}
       end
 
+      # Even if there is no value, an empty array will be returned.
       def [](name)
         return @frozen_values[name] if @frozen_values.key? name
 

lib/grape/validations/params_scope.rb

@@ -45,8 +45,10 @@ def configuration
       # @return [Boolean] whether or not this entire scope needs to be
       #   validated
       def should_validate?(parameters)
-        return false if @optional && (params(parameters).blank? || all_element_blank?(parameters))
-        return false unless meets_dependency?(params(parameters), parameters)
+        scoped_params = params(parameters)
+
+        return false if @optional && (scoped_params.blank? || all_element_blank?(scoped_params))
+        return false unless meets_dependency?(scoped_params, parameters)
         return true if parent.nil?
         parent.should_validate?(parameters)
       end
@@ -446,8 +448,8 @@ def options_key?(type, key, validations)
         validations[type].respond_to?(:key?) && validations[type].key?(key) && !validations[type][key].nil?
       end
 
-      def all_element_blank?(parameters)
-        params(parameters).respond_to?(:all?) && params(parameters).all?(&:blank?)
+      def all_element_blank?(scoped_params)
+        scoped_params.respond_to?(:all?) && scoped_params.all?(&:blank?)
       end
 
       # Validators don't have access to each other and they don't need, however,

lib/grape/validations/types/build_coercer.rb

@@ -83,7 +83,11 @@ def self.cache_instance(type, method, strict, &_block)
       end
 
       def self.cache_key(type, method, strict)
-        [type, method, strict].compact.map(&:to_s).join('_')
+        [type, method, strict].each_with_object(+'_') do |val, memo|
+          next if val.nil?
+
+          memo << '_' << val.to_s
+        end
       end
 
       instance_variable_set(:@__cache,            {})

spec/grape/api/instance_spec.rb

@@ -45,4 +45,10 @@ def app
       expect(last_response.body).to eq 'success'
     end
   end
+
+  context 'top level setting' do
+    it 'does not inherit settings from the superclass (Grape::API::Instance)' do
+      expect(an_instance.top_level_setting.parent).to be_nil
+    end
+  end
 end