From 289df4ce9b7e371be02ae8505e8d6513c9728e38 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Thu, 4 Jun 2020 17:24:36 +0200
Subject: [PATCH 1/6] Add inheritance and discriminator attributes

---
 lib/grape-swagger/entity/attribute_parser.rb  |  6 +-
 lib/grape-swagger/entity/parser.rb            | 42 ++++++++++-
 spec/grape-swagger/entity/parser_spec.rb      | 74 ++++++++++++++-----
 spec/spec_helper.rb                           |  1 +
 .../shared_contexts/inheritance_api.rb        | 16 ++++
 5 files changed, 118 insertions(+), 21 deletions(-)
 create mode 100644 spec/support/shared_contexts/inheritance_api.rb

diff --git a/lib/grape-swagger/entity/attribute_parser.rb b/lib/grape-swagger/entity/attribute_parser.rb
index cb3c6fe..e971d36 100644
--- a/lib/grape-swagger/entity/attribute_parser.rb
+++ b/lib/grape-swagger/entity/attribute_parser.rb
@@ -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
diff --git a/lib/grape-swagger/entity/parser.rb b/lib/grape-swagger/entity/parser.rb
index 2603285..49bf556 100644
--- a/lib/grape-swagger/entity/parser.rb
+++ b/lib/grape-swagger/entity/parser.rb
@@ -26,7 +26,13 @@ def initialize(original, renamed)
       end
 
       def extract_params(exposure)
-        exposure.root_exposures.each_with_object({}) do |value, memo|
+        root_exposures =
+          if superclass_contains_discriminator?(exposure)
+            root_exposures_without_parent(exposure)
+          else
+            exposure.root_exposures
+          end
+        root_exposures.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
 
@@ -39,6 +45,18 @@ def extract_params(exposure)
         end
       end
 
+      def superclass_contains_discriminator?(exposure)
+        exposure.superclass.root_exposures.detect do |value|
+          value.documentation[:is_discriminator]
+        end
+      end
+
+      def root_exposures_without_parent(exposure)
+        exposure.root_exposures.select do |value|
+          exposure.superclass.root_exposures.find_by(value.attribute).nil?
+        end
+      end
+
       def parse_grape_entity_params(params, parent_model = nil)
         return unless params
 
@@ -63,8 +81,28 @@ def parse_grape_entity_params(params, parent_model = nil)
           memo[final_entity_name][:readOnly] = documentation[:read_only].to_s == 'true' if documentation[:read_only]
           memo[final_entity_name][:description] = documentation[:desc] if documentation[:desc]
         end
+        if superclass_contains_discriminator?(model)
+          respond_with_all_of(parsed, params)
+        else
+          [parsed, required_params(params)]
+        end
+      end
 
-        [parsed, required_params(params)]
+      def respond_with_all_of(parsed, params)
+        parent_name =
+          if endpoint.nil?
+            model.superclass.to_s.demodulize
+          else
+            endpoint.send(:expose_params_from_model, model.superclass)
+          end
+        {
+          allOf: [
+            {
+              '$ref' => "#/definitions/#{parent_name}"
+            },
+            [parsed, required_params(params)]
+          ]
+        }
       end
 
       def parse_nested(entity_name, entity_options, parent_model = nil)
diff --git a/spec/grape-swagger/entity/parser_spec.rb b/spec/grape-swagger/entity/parser_spec.rb
index 889a968..6cfdad7 100644
--- a/spec/grape-swagger/entity/parser_spec.rb
+++ b/spec/grape-swagger/entity/parser_spec.rb
@@ -2,31 +2,69 @@
 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]
+          expect(all_of.first['$ref']).to eq('#/definitions/Parent')
+          expect(all_of.last.first[:name][:type]).to eq('string')
+        end
       end
     end
   end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index f8d6b10..c9bc034 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -7,6 +7,7 @@
 
 require 'rack'
 require 'rack/test'
+require 'pry'
 
 RSpec.configure do |config|
   require 'rspec/expectations'
diff --git a/spec/support/shared_contexts/inheritance_api.rb b/spec/support/shared_contexts/inheritance_api.rb
new file mode 100644
index 0000000..bc40812
--- /dev/null
+++ b/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

From 2fb7c32781b2cac1fe840ecb9b64840e7c4f30b4 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Thu, 4 Jun 2020 17:58:08 +0200
Subject: [PATCH 2/6] documentation could be nil

---
 lib/grape-swagger/entity/parser.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/grape-swagger/entity/parser.rb b/lib/grape-swagger/entity/parser.rb
index 49bf556..0c4d413 100644
--- a/lib/grape-swagger/entity/parser.rb
+++ b/lib/grape-swagger/entity/parser.rb
@@ -47,7 +47,7 @@ def extract_params(exposure)
 
       def superclass_contains_discriminator?(exposure)
         exposure.superclass.root_exposures.detect do |value|
-          value.documentation[:is_discriminator]
+          value.documentation.try(:[], :is_discriminator)
         end
       end
 

From f05375d1f57536a4092dfe289fcb5b10fc76c1c4 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Fri, 5 Jun 2020 11:14:42 +0200
Subject: [PATCH 3/6] Add required type and property

---
 lib/grape-swagger/entity.rb                  |  1 +
 lib/grape-swagger/entity/attribute_parser.rb |  2 +-
 lib/grape-swagger/entity/helper.rb           | 13 ++++++++
 lib/grape-swagger/entity/parser.rb           | 32 ++++++++++++++++----
 spec/grape-swagger/entity/parser_spec.rb     |  7 ++++-
 5 files changed, 47 insertions(+), 8 deletions(-)
 create mode 100644 lib/grape-swagger/entity/helper.rb

diff --git a/lib/grape-swagger/entity.rb b/lib/grape-swagger/entity.rb
index 51828d7..23d5ace 100644
--- a/lib/grape-swagger/entity.rb
+++ b/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'
 
diff --git a/lib/grape-swagger/entity/attribute_parser.rb b/lib/grape-swagger/entity/attribute_parser.rb
index e971d36..86de296 100644
--- a/lib/grape-swagger/entity/attribute_parser.rb
+++ b/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
diff --git a/lib/grape-swagger/entity/helper.rb b/lib/grape-swagger/entity/helper.rb
new file mode 100644
index 0000000..44f8f33
--- /dev/null
+++ b/lib/grape-swagger/entity/helper.rb
@@ -0,0 +1,13 @@
+module GrapeSwagger
+  module Entity
+    class Helper
+      def self.model_name(entity_model, endpoint)
+        if endpoint.nil?
+          entity_model.to_s.demodulize
+        else
+          endpoint.send(:expose_params_from_model, entity_model)
+        end
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/grape-swagger/entity/parser.rb b/lib/grape-swagger/entity/parser.rb
index 0c4d413..7002456 100644
--- a/lib/grape-swagger/entity/parser.rb
+++ b/lib/grape-swagger/entity/parser.rb
@@ -27,7 +27,7 @@ def initialize(original, renamed)
 
       def extract_params(exposure)
         root_exposures =
-          if superclass_contains_discriminator?(exposure)
+          if discriminator(exposure)
             root_exposures_without_parent(exposure)
           else
             exposure.root_exposures
@@ -45,7 +45,7 @@ def extract_params(exposure)
         end
       end
 
-      def superclass_contains_discriminator?(exposure)
+      def discriminator(exposure)
         exposure.superclass.root_exposures.detect do |value|
           value.documentation.try(:[], :is_discriminator)
         end
@@ -81,15 +81,19 @@ def parse_grape_entity_params(params, parent_model = nil)
           memo[final_entity_name][:readOnly] = documentation[:read_only].to_s == 'true' if documentation[:read_only]
           memo[final_entity_name][:description] = documentation[:desc] if documentation[:desc]
         end
-        if superclass_contains_discriminator?(model)
-          respond_with_all_of(parsed, params)
+
+        discriminator = 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)
+      def respond_with_all_of(parsed, params, discriminator)
         parent_name =
+          GrapeSwagger::Entity::Helper.model_name(model.superclass, endpoint)
+
           if endpoint.nil?
             model.superclass.to_s.demodulize
           else
@@ -100,11 +104,27 @@ def respond_with_all_of(parsed, params)
             {
               '$ref' => "#/definitions/#{parent_name}"
             },
-            [parsed, required_params(params)]
+            [
+              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)
         nested_entity = if parent_model.nil?
                           model.root_exposures.find_by(entity_name)
diff --git a/spec/grape-swagger/entity/parser_spec.rb b/spec/grape-swagger/entity/parser_spec.rb
index 6cfdad7..f781f3a 100644
--- a/spec/grape-swagger/entity/parser_spec.rb
+++ b/spec/grape-swagger/entity/parser_spec.rb
@@ -62,8 +62,13 @@
         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(all_of.last.first[:name][:type]).to eq('string')
+          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

From 1286b1e8068b09d58b8bab7aaeb77d8cc6ccc843 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Fri, 5 Jun 2020 11:40:21 +0200
Subject: [PATCH 4/6] Fix rubocop

---
 lib/grape-swagger/entity/helper.rb | 35 ++++++++++++++++++++++-----
 lib/grape-swagger/entity/parser.rb | 38 +++++-------------------------
 2 files changed, 35 insertions(+), 38 deletions(-)

diff --git a/lib/grape-swagger/entity/helper.rb b/lib/grape-swagger/entity/helper.rb
index 44f8f33..0a01b49 100644
--- a/lib/grape-swagger/entity/helper.rb
+++ b/lib/grape-swagger/entity/helper.rb
@@ -1,13 +1,36 @@
 module GrapeSwagger
   module Entity
+    # Helper methods for DRY
     class Helper
-      def self.model_name(entity_model, endpoint)
-        if endpoint.nil?
-          entity_model.to_s.demodulize
-        else
-          endpoint.send(:expose_params_from_model, entity_model)
+      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.try(:[], :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
\ No newline at end of file
+end
diff --git a/lib/grape-swagger/entity/parser.rb b/lib/grape-swagger/entity/parser.rb
index 7002456..41cc169 100644
--- a/lib/grape-swagger/entity/parser.rb
+++ b/lib/grape-swagger/entity/parser.rb
@@ -26,13 +26,7 @@ def initialize(original, renamed)
       end
 
       def extract_params(exposure)
-        root_exposures =
-          if discriminator(exposure)
-            root_exposures_without_parent(exposure)
-          else
-            exposure.root_exposures
-          end
-        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
 
@@ -45,18 +39,6 @@ def extract_params(exposure)
         end
       end
 
-      def discriminator(exposure)
-        exposure.superclass.root_exposures.detect do |value|
-          value.documentation.try(:[], :is_discriminator)
-        end
-      end
-
-      def root_exposures_without_parent(exposure)
-        exposure.root_exposures.select do |value|
-          exposure.superclass.root_exposures.find_by(value.attribute).nil?
-        end
-      end
-
       def parse_grape_entity_params(params, parent_model = nil)
         return unless params
 
@@ -82,7 +64,7 @@ def parse_grape_entity_params(params, parent_model = nil)
           memo[final_entity_name][:description] = documentation[:desc] if documentation[:desc]
         end
 
-        discriminator = discriminator(model)
+        discriminator = GrapeSwagger::Entity::Helper.discriminator(model)
         if discriminator
           respond_with_all_of(parsed, params, discriminator)
         else
@@ -91,14 +73,8 @@ def parse_grape_entity_params(params, parent_model = nil)
       end
 
       def respond_with_all_of(parsed, params, discriminator)
-        parent_name =
-          GrapeSwagger::Entity::Helper.model_name(model.superclass, endpoint)
+        parent_name = GrapeSwagger::Entity::Helper.model_name(model.superclass, endpoint)
 
-          if endpoint.nil?
-            model.superclass.to_s.demodulize
-          else
-            endpoint.send(:expose_params_from_model, model.superclass)
-          end
         {
           allOf: [
             {
@@ -116,11 +92,9 @@ def add_discriminator(parsed, discriminator)
         model_name = GrapeSwagger::Entity::Helper.model_name(model, endpoint)
 
         parsed.merge(
-          {
-            discriminator.attribute => {
-              type: 'string',
-              enum: [model_name]
-            }
+          discriminator.attribute => {
+            type: 'string',
+            enum: [model_name]
           }
         )
       end

From 7762b53045694e6d714af617c95e678048ff7c67 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Fri, 5 Jun 2020 12:12:20 +0200
Subject: [PATCH 5/6] Add changelog

---
 CHANGELOG.md | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2279eab..b426c1b 100644
--- a/CHANGELOG.md
+++ b/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)
 

From 0422d686af4a1e9ea1a5c9d0870304bca6cf0704 Mon Sep 17 00:00:00 2001
From: Maxime Raverdy <maxime.raverdy@gmail.com>
Date: Fri, 12 Jun 2020 10:58:17 +0200
Subject: [PATCH 6/6] Fix code

---
 lib/grape-swagger/entity/helper.rb | 2 +-
 spec/spec_helper.rb                | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/grape-swagger/entity/helper.rb b/lib/grape-swagger/entity/helper.rb
index 0a01b49..f88ece0 100644
--- a/lib/grape-swagger/entity/helper.rb
+++ b/lib/grape-swagger/entity/helper.rb
@@ -13,7 +13,7 @@ def model_name(entity_model, endpoint)
 
         def discriminator(entity_model)
           entity_model.superclass.root_exposures.detect do |value|
-            value.documentation.try(:[], :is_discriminator)
+            value.documentation.dig(:is_discriminator)
           end
         end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index c9bc034..f8d6b10 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -7,7 +7,6 @@
 
 require 'rack'
 require 'rack/test'
-require 'pry'
 
 RSpec.configure do |config|
   require 'rspec/expectations'