Change way of finding policy for scopes (#29)

* Change way of finding policy for scopes

* Fix weird sharing error

* Obey review

* Bump patch version

lib/graphql-pundit/instrumenters/scope.rb

@@ -19,11 +19,12 @@ def initialize(current_user, scope, old_resolver)
               raise ArgumentError, 'Invalid value passed to `scope`'
             end
 
-            @scope = new_scope(scope)
+            @scope = scope
           end
 
           def call(root, arguments, context)
-            new_scope = scope.call(root, arguments, context)
+            scope_proc = new_scope(scope)
+            new_scope = scope_proc.call(root, arguments, context)
             old_resolver.call(new_scope, arguments, context)
           end
 
@@ -33,11 +34,23 @@ def new_scope(scope)
             return scope if proc?(scope)
 
             lambda do |root, _arguments, context|
-              unless inferred?(scope)
-                root.define_singleton_method(:policy_class) { scope }
-              end
+              scope = find_scope(root, scope)
+              scope.new(context[current_user], root).resolve
+            end
+          end
 
-              ::Pundit.policy_scope!(context[current_user], root)
+          def find_scope(root, scope)
+            if !inferred?(scope)
+              scope::Scope
+            else
+              # Special case for Sequel datasets that do not respond to
+              # ActiveModel's model_name
+              infer_from = if root.respond_to?(:model)
+                             root.model
+                           else
+                             root
+                           end
+              ::Pundit::PolicyFinder.new(infer_from).scope!
             end
           end
 

lib/graphql-pundit/version.rb

@@ -2,6 +2,6 @@
 
 module GraphQL
   module Pundit
-    VERSION = '0.5.0'
+    VERSION = '0.5.1'
   end
 end

spec/graphql-pundit/instrumenters/scope_spec.rb

@@ -16,6 +16,12 @@ def to_a
   end
 end
 
+class ScopeTestDataset < ScopeTest
+  def model
+    ScopeTest
+  end
+end
+
 class ScopeTestPolicy
   class Scope
     attr_reader :scope
@@ -56,6 +62,21 @@ def test?
       it 'filters the list' do
         expect(result).to match_array([1, 2, 3])
       end
+
+      context 'scope from model' do
+        subject { ScopeTestDataset.new([1, 2, 3, 22, 48]) }
+        let(:field) do
+          GraphQL::Field.define(type: 'String') do
+            name :notTest
+            scope
+            resolve ->(obj, _args, _ctx) { obj.to_a }
+          end
+        end
+
+        it 'filters the list' do
+          expect(result).to match_array([1, 2, 3])
+        end
+      end
     end
 
     context 'explicit scope proc' do
@@ -101,6 +122,22 @@ def test?
       it 'returns nil' do
         expect(result).to eq(nil)
       end
+
+      context 'scope from model' do
+        subject { ScopeTestDataset.new([1, 2, 3, 22, 48]) }
+        let(:field) do
+          GraphQL::Field.define(type: 'String') do
+            name :test
+            authorize policy: :scope_test
+            scope
+            resolve ->(obj, _args, _ctx) { obj.to_a }
+          end
+        end
+
+        it 'returns nil' do
+          expect(result).to eq(nil)
+        end
+      end
     end
 
     context 'explicit scope proc' do