Allow scopes access to runtime context

In Rails, this means scopes would have access controller.
So you can do things like:

```ruby
default_filter :foo do |scope, ctx|
  scope.where(user_id: ctx.current_user.id)
end
```

Author: Lee Richmond

lib/generators/jsonapi/field_generator.rb

@@ -38,7 +38,7 @@ class Scoping::DefaultFilter < Scoping::Base
     def apply
       resource.default_filters.each_pair do |name, opts|
         next if overridden?(name)
-        @scope = opts[:filter].call(@scope)
+        @scope = opts[:filter].call(@scope, resource.context)
       end
 
       @scope

lib/jsonapi_compliable/scoping/default_filter.rb

@@ -35,7 +35,7 @@ class Scoping::ExtraFields < Scoping::Base
     # @return the scope object we are chaining/modofying
     def apply
       each_extra_field do |callable|
-        @scope = callable.call(@scope)
+        @scope = callable.call(@scope, resource.context)
       end
 
       @scope

lib/jsonapi_compliable/scoping/extra_fields.rb

@@ -41,7 +41,7 @@ def apply
     # specified in the adapter.
     def filter_scope(filter, value)
       if custom_scope = filter.values.first[:filter]
-        custom_scope.call(@scope, value)
+        custom_scope.call(@scope, value, resource.context)
       else
         resource.adapter.filter(@scope, filter.keys.first, value)
       end

lib/jsonapi_compliable/scoping/filter.rb

@@ -61,7 +61,7 @@ def apply_standard_scope
 
     # Apply the custom pagination proc
     def apply_custom_scope
-      custom_scope.call(@scope, number, size)
+      custom_scope.call(@scope, number, size, resource.context)
     end
 
     private

lib/jsonapi_compliable/scoping/paginate.rb

@@ -31,7 +31,8 @@ def apply_standard_scope
     # @return the scope we are chaining/modifying
     def apply_custom_scope
       each_sort do |attribute, direction|
-        @scope = custom_scope.call(@scope, attribute, direction)
+        @scope = custom_scope
+          .call(@scope, attribute, direction, resource.context)
       end
       @scope
     end

lib/jsonapi_compliable/scoping/sort.rb

@@ -9,19 +9,36 @@ class SerializableTestExtraFields < JSONAPI::Serializable::Resource
     extra_attribute :net_worth, if: proc { !@context || @context.allow_net_worth? } do
       100_000_000
     end
+
+    extra_attribute :runtime_id do
+      @context.runtime_id
+    end
   end
 
   before do
     resource_class.class_eval do
       extra_field :net_worth do |scope|
         scope.include_foo!
       end
+
+      extra_field :runtime_id do |scope, ctx|
+        scope.runtime_id = ctx.runtime_id
+        scope
+      end
     end
   end
 
   let!(:scope_object) do
     scope = Author.all
     scope.instance_eval do
+      def runtime_id=(val)
+        @runtime_id = val
+      end
+
+      def runtime_id
+        @runtime_id
+      end
+
       def include_foo!
         self
       end
@@ -53,6 +70,21 @@ def include_foo!
     expect(json['data'][0]['attributes'].keys).to match_array(%w(first_name last_name net_worth))
   end
 
+  context 'when accessing runtime context' do
+    before do
+      params[:extra_fields] = { authors: 'runtime_id' }
+    end
+
+    it 'works' do
+      expect(scope_object).to receive(:runtime_id=).with(789)
+      ctx = double(runtime_id: 789).as_null_object
+      resource.with_context ctx do
+        attrs = json['data'][0]['attributes']
+        expect(attrs['runtime_id']).to eq(789)
+      end
+    end
+  end
+
   context 'when extra field is requested but guarded' do
     before do
       params[:extra_fields] = { authors: 'net_worth' }

spec/extra_fields_spec.rb

@@ -14,6 +14,9 @@
         scope.where(['first_name like ?', "#{value}%"])
       end
       allow_filter :active
+      allow_filter :temp do |scope, value, ctx|
+        scope.where(id: ctx.runtime_id)
+      end
     end
   end
 
@@ -27,6 +30,15 @@
     expect(scope.resolve.map(&:id)).to eq([author1.id])
   end
 
+  # For example, getting current user from controller
+  it 'has access to calling context' do
+    ctx = double(runtime_id: author3.id).as_null_object
+    JsonapiCompliable.with_context(ctx, {}) do
+      params[:filter] = { temp: true }
+      expect(scope.resolve.map(&:id)).to eq([author3.id])
+    end
+  end
+
   context 'when filter is a "string nil"' do
     before do
       params[:filter] = { first_name: 'nil' }
@@ -137,6 +149,23 @@
       params[:filter] = { name: 'Stephen' }
       expect(scope.resolve.map(&:id)).to eq([author1.id])
     end
+
+    context 'when accessing calling context' do
+      before do
+        resource_class.class_eval do
+          default_filter :first_name do |scope, ctx|
+            scope.where(id: ctx.runtime_id)
+          end
+        end
+      end
+
+      it 'works' do
+        ctx = double(runtime_id: author3.id).as_null_object
+        JsonapiCompliable.with_context(ctx, {}) do
+          expect(scope.resolve.map(&:id)).to eq([author3.id])
+        end
+      end
+    end
   end
 
   context 'when the filter is guarded' do

spec/filtering_spec.rb

@@ -52,5 +52,22 @@
     it 'uses the custom pagination function' do
       expect(scope.resolve).to eq([])
     end
+
+    context 'and it accesses runtime context' do
+      before do
+        resource_class.class_eval do
+          paginate do |scope, page, per_page, ctx|
+            scope.limit(ctx.runtime_limit)
+          end
+        end
+      end
+
+      it 'works' do
+        ctx = double(runtime_limit: 2).as_null_object
+        JsonapiCompliable.with_context(ctx, {}) do
+          expect(scope.resolve.length).to eq(2)
+        end
+      end
+    end
   end
 end

spec/pagination_spec.rb

@@ -2,11 +2,17 @@
 
 RSpec.describe JsonapiCompliable::Scope do
   let(:object)     { double.as_null_object }
-  let(:resource)   { double(type: :authors, default_page_size: 1).as_null_object }
   let(:query_hash) { JsonapiCompliable::Query.default_hash }
   let(:query)      { double(to_hash: { authors: query_hash }) }
   let(:instance)   { described_class.new(object, resource, query) }
 
+  let(:resource) do
+    dbl = double type: :authors,
+      default_page_size: 1,
+      pagination: nil
+    dbl.as_null_object
+  end
+
   describe '#resolve' do
     before do
       allow(query).to receive(:zero_results?) { false }