Merge pull request #50 from MaximeRDY/features/inheritance_and_discri…

…minator

Features/inheritance and discriminator

CHANGELOG.md

@@ -3,10 +3,7 @@
 #### Features
 
 * Your contribution here.
-
-#### Features
-
-* Your contribution here.
+* [#50](https://github.com/ruby-grape/grape-swagger-entity/pull/50): Features/inheritance and discriminator - [@MaximeRDY](https://github.com/MaximeRDY).
 
 ### 0.4.0 (May 30, 2020)
 

lib/grape-swagger/entity.rb

@@ -2,6 +2,7 @@
 require 'grape-entity'
 
 require 'grape-swagger/entity/version'
+require 'grape-swagger/entity/helper'
 require 'grape-swagger/entity/attribute_parser'
 require 'grape-swagger/entity/parser'
 

lib/grape-swagger/entity/attribute_parser.rb

@@ -12,7 +12,7 @@ def call(entity_options)
         entity_model = model_from(entity_options)
 
         if entity_model
-          name = endpoint.nil? ? entity_model.to_s.demodulize : endpoint.send(:expose_params_from_model, entity_model)
+          name = GrapeSwagger::Entity::Helper.model_name(entity_model, endpoint)
 
           entity_model_type = entity_model_type(name, entity_options)
           return entity_model_type unless documentation
@@ -39,7 +39,7 @@ def call(entity_options)
           add_attribute_documentation(param, documentation)
 
           add_extension_documentation(param, documentation)
-
+          add_discriminator_extension(param, documentation)
           param
         end
       end
@@ -128,6 +128,10 @@ def add_array_documentation(param, documentation)
       def add_extension_documentation(param, documentation)
         GrapeSwagger::DocMethods::Extensions.add_extensions_to_root(documentation, param)
       end
+
+      def add_discriminator_extension(param, documentation)
+        param[:documentation] = { is_discriminator: true } if documentation.key?(:is_discriminator)
+      end
     end
   end
 end

lib/grape-swagger/entity/helper.rb

@@ -0,0 +1,36 @@
+module GrapeSwagger
+  module Entity
+    # Helper methods for DRY
+    class Helper
+      class << self
+        def model_name(entity_model, endpoint)
+          if endpoint.nil?
+            entity_model.to_s.demodulize
+          else
+            endpoint.send(:expose_params_from_model, entity_model)
+          end
+        end
+
+        def discriminator(entity_model)
+          entity_model.superclass.root_exposures.detect do |value|
+            value.documentation.dig(:is_discriminator)
+          end
+        end
+
+        def root_exposures_without_parent(entity_model)
+          entity_model.root_exposures.select do |value|
+            entity_model.superclass.root_exposures.find_by(value.attribute).nil?
+          end
+        end
+
+        def root_exposure_with_discriminator(entity_model)
+          if discriminator(entity_model)
+            root_exposures_without_parent(entity_model)
+          else
+            entity_model.root_exposures
+          end
+        end
+      end
+    end
+  end
+end

lib/grape-swagger/entity/parser.rb

@@ -26,7 +26,7 @@ def initialize(original, renamed)
       end
 
       def extract_params(exposure)
-        exposure.root_exposures.each_with_object({}) do |value, memo|
+        GrapeSwagger::Entity::Helper.root_exposure_with_discriminator(exposure).each_with_object({}) do |value, memo|
           if value.for_merge && (value.respond_to?(:entity_class) || value.respond_to?(:using_class_name))
             entity_class = value.respond_to?(:entity_class) ? value.entity_class : value.using_class_name
 
@@ -64,7 +64,39 @@ def parse_grape_entity_params(params, parent_model = nil)
           memo[final_entity_name][:description] = documentation[:desc] if documentation[:desc]
         end
 
-        [parsed, required_params(params)]
+        discriminator = GrapeSwagger::Entity::Helper.discriminator(model)
+        if discriminator
+          respond_with_all_of(parsed, params, discriminator)
+        else
+          [parsed, required_params(params)]
+        end
+      end
+
+      def respond_with_all_of(parsed, params, discriminator)
+        parent_name = GrapeSwagger::Entity::Helper.model_name(model.superclass, endpoint)
+
+        {
+          allOf: [
+            {
+              '$ref' => "#/definitions/#{parent_name}"
+            },
+            [
+              add_discriminator(parsed, discriminator),
+              required_params(params).push(discriminator.attribute)
+            ]
+          ]
+        }
+      end
+
+      def add_discriminator(parsed, discriminator)
+        model_name = GrapeSwagger::Entity::Helper.model_name(model, endpoint)
+
+        parsed.merge(
+          discriminator.attribute => {
+            type: 'string',
+            enum: [model_name]
+          }
+        )
       end
 
       def parse_nested(entity_name, entity_options, parent_model = nil)

spec/grape-swagger/entity/parser_spec.rb

@@ -2,31 +2,74 @@
 require_relative '../../../spec/support/shared_contexts/this_api'
 
 describe GrapeSwagger::Entity::Parser do
-  include_context 'this api'
+  context 'this api' do
+    include_context 'this api'
 
-  describe '#call' do
-    let(:parsed_entity) { described_class.new(ThisApi::Entities::Something, endpoint).call }
-    let(:properties) { parsed_entity.first }
-    let(:required) { parsed_entity.last }
+    describe '#call' do
+      let(:parsed_entity) { described_class.new(ThisApi::Entities::Something, endpoint).call }
+      let(:properties) { parsed_entity.first }
+      let(:required) { parsed_entity.last }
 
-    context 'when no endpoint is passed' do
-      let(:endpoint) { nil }
+      context 'when no endpoint is passed' do
+        let(:endpoint) { nil }
 
-      it 'parses the model with the correct :using definition' do
-        expect(properties[:kind]['$ref']).to eq('#/definitions/Kind')
-        expect(properties[:kind2]['$ref']).to eq('#/definitions/Kind')
-        expect(properties[:kind3]['$ref']).to eq('#/definitions/Kind')
+        it 'parses the model with the correct :using definition' do
+          expect(properties[:kind]['$ref']).to eq('#/definitions/Kind')
+          expect(properties[:kind2]['$ref']).to eq('#/definitions/Kind')
+          expect(properties[:kind3]['$ref']).to eq('#/definitions/Kind')
+        end
+
+        it 'merges attributes that have merge: true defined' do
+          expect(properties[:merged_attribute]).to be_nil
+          expect(properties[:code][:type]).to eq('string')
+          expect(properties[:message][:type]).to eq('string')
+          expect(properties[:attr][:type]).to eq('string')
+        end
+
+        it 'hides hidden attributes' do
+          expect(properties).to_not include(:hidden_attr)
+        end
       end
+    end
+  end
+  context 'inheritance api' do
+    include_context 'inheritance api'
 
-      it 'merges attributes that have merge: true defined' do
-        expect(properties[:merged_attribute]).to be_nil
-        expect(properties[:code][:type]).to eq('string')
-        expect(properties[:message][:type]).to eq('string')
-        expect(properties[:attr][:type]).to eq('string')
+    describe '#call for Parent' do
+      let(:parsed_entity) do
+        described_class.new(InheritanceApi::Entities::Parent, endpoint).call
       end
+      let(:properties) { parsed_entity.first }
+
+      context 'when no endpoint is passed' do
+        let(:endpoint) { nil }
+
+        it 'parses the model with discriminator' do
+          expect(properties[:type][:documentation]).to eq(is_discriminator: true)
+        end
+      end
+    end
+
+    describe '#call for Child' do
+      let(:parsed_entity) do
+        described_class.new(InheritanceApi::Entities::Child, endpoint).call
+      end
+      let(:properties) { parsed_entity }
+
+      context 'when no endpoint is passed' do
+        let(:endpoint) { nil }
 
-      it 'hides hidden attributes' do
-        expect(properties).to_not include(:hidden_attr)
+        it 'parses the model with allOf' do
+          expect(properties).to include(:allOf)
+          all_of = properties[:allOf]
+          child_property = all_of.last.first
+          child_required = all_of.last.last
+          expect(all_of.first['$ref']).to eq('#/definitions/Parent')
+          expect(child_property[:name][:type]).to eq('string')
+          expect(child_property[:type][:type]).to eq('string')
+          expect(child_property[:type][:enum]).to eq(['Child'])
+          expect(child_required).to include(:type)
+        end
       end
     end
   end

spec/support/shared_contexts/inheritance_api.rb

@@ -0,0 +1,16 @@
+shared_context 'inheritance api' do
+  before :all do
+    module InheritanceApi
+      module Entities
+        class Parent < Grape::Entity
+          expose :type, documentation: { type: 'string', is_discriminator: true, required: true }
+          expose :id, documentation: { type: 'integer' }
+        end
+
+        class Child < Parent
+          expose :name, documentation: { type: 'string', desc: 'Name' }
+        end
+      end
+    end
+  end
+end