Improve subclass customization

Author: Lee Richmond

lib/jsonapi_compliable/base.rb

@@ -101,7 +101,10 @@ def jsonapi(&blk)
         if !self._jsonapi_compliable
           dsl = JsonapiCompliable::DSL.new
           self._jsonapi_compliable = dsl
+        else
+          self._jsonapi_compliable = self._jsonapi_compliable.copy
         end
+
         self._jsonapi_compliable.instance_eval(&blk)
       end
     end

lib/jsonapi_compliable/dsl.rb

@@ -8,6 +8,21 @@ class DSL
       :pagination
 
     def initialize
+      clear!
+    end
+
+    def copy
+      instance = self.class.new
+      instance.sideloads = sideloads.deep_dup
+      instance.filters = filters.deep_dup
+      instance.default_filters = default_filters.deep_dup
+      instance.extra_fields = extra_fields.deep_dup
+      instance.sorting = sorting.deep_dup
+      instance.pagination = pagination.deep_dup
+      instance
+    end
+
+    def clear!
       @sideloads = {}
       @filters = {}
       @default_filters = {}

spec/dsl_spec.rb

@@ -0,0 +1,97 @@
+require 'spec_helper'
+
+RSpec.describe JsonapiCompliable::DSL do
+  let(:instance) { described_class.new }
+
+  describe '#copy' do
+    let(:copy) { instance.copy }
+
+    it 'returns a new instance' do
+      expect(copy).to be_a(described_class)
+      expect(copy.object_id).to_not eq(instance.object_id)
+    end
+
+    it 'copies sideloads' do
+      instance.sideloads = { foo: 'bar' }
+      expect(copy.sideloads).to eq(foo: 'bar')
+      expect(copy.sideloads.object_id).to_not eq(instance.sideloads.object_id)
+    end
+
+    it 'copies filters' do
+      instance.filters = { foo: 'bar' }
+      expect(copy.filters).to eq(foo: 'bar')
+      expect(copy.filters.object_id).to_not eq(instance.filters.object_id)
+    end
+
+    it 'copies default filters' do
+      instance.default_filters = { foo: 'bar' }
+      expect(copy.default_filters).to eq(foo: 'bar')
+      expect(copy.default_filters.object_id).to_not eq(instance.default_filters.object_id)
+    end
+
+    it 'copies extra fields' do
+      instance.extra_fields = { foo: 'bar' }
+      expect(copy.extra_fields).to eq(foo: 'bar')
+      expect(copy.extra_fields.object_id).to_not eq(instance.extra_fields.object_id)
+    end
+
+    it 'copies sorting' do
+      instance.sorting = 'a'
+      expect(copy.sorting).to eq(instance.sorting)
+      expect(copy.sorting.object_id).to_not eq(instance.sorting.object_id)
+    end
+
+    it 'copies pagination' do
+      instance.pagination = 'a'
+      expect(copy.pagination).to eq(instance.pagination)
+      expect(copy.pagination.object_id).to_not eq(instance.pagination.object_id)
+    end
+  end
+
+  describe '#clear' do
+    before do
+      instance.sideloads = { foo: 'bar' }
+      instance.filters = { foo: 'bar' }
+      instance.default_filters = { foo: 'bar' }
+      instance.extra_fields = { foo: 'bar' }
+      instance.sorting = 'a'
+      instance.pagination = 'a'
+    end
+
+    it 'resets sideloads' do
+      expect {
+        instance.clear!
+      }.to change { instance.sideloads }.to({})
+    end
+
+    it 'resets filters' do
+      expect {
+        instance.clear!
+      }.to change { instance.filters }.to({})
+    end
+
+    it 'resets default filters' do
+      expect {
+        instance.clear!
+      }.to change { instance.default_filters }.to({})
+    end
+
+    it 'resets extra fields' do
+      expect {
+        instance.clear!
+      }.to change { instance.extra_fields }.to({})
+    end
+
+    it 'resets sorting' do
+      expect {
+        instance.clear!
+      }.to change { instance.sorting }.to(nil)
+    end
+
+    it 'resets pagination' do
+      expect {
+        instance.clear!
+      }.to change { instance.pagination }.to(nil)
+    end
+  end
+end

spec/jsonapi_compliable_spec.rb

@@ -10,6 +10,42 @@ def index
     end
   end
 
+  describe '.jsonapi' do
+    let(:subclass1) do
+      Class.new(controller.class) do
+        jsonapi do
+          allow_filter :id
+          allow_filter :foo
+        end
+      end
+    end
+
+    let(:subclass2) do
+      Class.new(subclass1) do
+        jsonapi do
+          allow_filter :foo do |scope, value|
+            'foo'
+          end
+        end
+      end
+    end
+
+    context 'when subclassing and customizing' do
+      it 'preserves values from superclass' do
+        expect(subclass2._jsonapi_compliable.filters[:id]).to_not be_nil
+      end
+
+      it 'does not alter superclass when overriding' do
+        expect(subclass1._jsonapi_compliable)
+          .to_not eq(subclass2._jsonapi_compliable)
+        expect(subclass1._jsonapi_compliable.filters[:id].object_id)
+          .to_not eq(subclass2._jsonapi_compliable.filters[:id].object_id)
+        expect(subclass1._jsonapi_compliable.filters[:foo][:filter]).to be_nil
+        expect(subclass2._jsonapi_compliable.filters[:foo][:filter]).to_not be_nil
+      end
+    end
+  end
+
   describe '#render_ams' do
     it 'is able to override options' do
       author = Author.create!(first_name: 'Stephen', last_name: 'King')