[BDO-348] Add custom pundit macros (#329)

.reek.yml

@@ -22,6 +22,7 @@ detectors:
 
   TooManyStatements:
     exclude:
+      - Macro#self.Policy
       - DefaultEndpoint#default_cases
       - DefaultEndpoint#default_handler
       - Macro#self.Decorate
@@ -61,6 +62,7 @@ detectors:
       - Macro#self.Model
       - Macro#self.Assign
       - Macro#self.Decorate
+      - Macro#self.Policy
 
   BooleanParameter:
     exclude:

.rubocop.yml

@@ -64,6 +64,9 @@ Rails/IndexWith:
     - lib/macro/schema.rb
 
 # Metrics ---------------------------------------------------------------------
+Metrics/ParameterLists:
+  Exclude:
+    - lib/macro/policy.rb
 
 Metrics/BlockLength:
   ExcludedMethods:
@@ -79,8 +82,7 @@ Metrics/BlockLength:
 Metrics/AbcSize:
   Exclude:
     - app/controllers/concerns/default_endpoint.rb
-    - lib/macro/model.rb
-    - lib/macro/links_builder.rb
+    - lib/macro/*.rb
 
 Metrics/MethodLength:
   Max: 15

README.md

@@ -29,6 +29,7 @@ Project wiki: https://github.com/rubygarage/boilerplate/wiki
 | ```Macro::ModelRemove``` | Provides to destroy and delete model. |
 | ```Macro::Renderer``` | Provides to render operation result with specified serializer with strict following Jsonapi specification |
 | ```Macro::Semantic``` | Provides to set value of semantic marker (```semantic_success``` or ```semantic_failure```) into context |
+| ```Macro::Policy``` | Set semantic marker ```semantic_failure``` to equel ```:forbidden``` and add errors if no policy|
 
 ### Services
 

lib/macro/policy.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Macro
+  def self.Policy(policy_class, rule, policy_params: nil, name: :default, model: :model, **)
+    task = ->((ctx, flow_options), **) {
+      policy_namespace = :"macro.policy.#{name}"
+      ctx[policy_namespace] = policy_class.new(ctx[:current_user], ctx[model])
+      result = if policy_params
+                 ctx[policy_namespace].public_send(rule, ctx[:policy_params])
+               else
+                 ctx[policy_namespace].public_send(rule)
+               end
+      unless result
+        message = "#{policy_class.name.demodulize.underscore}.#{rule}" || 'default'
+        current_errors = ctx[:errors] || {}
+        ctx[:errors] = current_errors.deep_merge(
+          {
+            policy: [I18n.t("policy.errors.#{message}")]
+          }
+        )
+
+        ctx[:semantic_failure] = :forbidden
+      end
+
+      signal = result ? Trailblazer::Activity::Right : Trailblazer::Activity::Left
+      [signal, [ctx, flow_options]]
+    }
+
+    { task: task, id: "#{name}/#{__method__}_id_#{task.object_id}".underscore }
+  end
+end

spec/lib/macro/policy_spec.rb

@@ -0,0 +1,71 @@
+# frozen_string_literal: true
+
+RSpec.describe Macro do
+  describe '.Policy' do
+    subject(:result) { described_class::Policy(policy_class, rule)[:task].call(ctx, **flow_options) }
+
+    let(:flow_options) { {} }
+    let(:rule) { :update_role? }
+    let(:ctx) { {} }
+    let(:policy_class) { TestPolicy }
+
+    before { stub_const('TestPolicy', Struct.new(:TestPolicy)) }
+
+    context 'when set policy_params to true' do
+      subject(:result) do
+        described_class::Policy(policy_class,
+                                rule,
+                                policy_params: true)[:task].call(ctx, **flow_options)
+      end
+
+      let(:ctx) { { policy_params: true } }
+
+      it 'is allowed' do
+        expect(policy_class).to receive_message_chain(:new, rule).with(ctx[:policy_params]).and_return(true)
+        expect(result[0]).to eq(Trailblazer::Activity::Right)
+      end
+    end
+
+    context 'when current_user in have access to model' do
+      before do
+        allow(policy_class).to receive_message_chain(:new, rule).and_return(true)
+      end
+
+      it 'is allowed' do
+        expect(result[0]).to eq(Trailblazer::Activity::Right)
+        expect(ctx[:semantic_failure]).to be_nil
+      end
+
+      it 'is put policy in right namespace' do
+        expect(result.second.first[:'macro.policy.default']).to be_instance_of(RSpec::Mocks::Double)
+        expect(result[1][0][:'macro.policy.default']).to be_respond_to(rule)
+      end
+    end
+
+    context 'when current_user in have not access to model' do
+      before do
+        allow(policy_class).to receive_message_chain(:new, rule).and_return(false)
+      end
+
+      it 'is not allowed' do
+        expect(result[0]).to eq(Trailblazer::Activity::Left)
+        expect(ctx[:semantic_failure]).to eq(:forbidden)
+      end
+    end
+
+    context 'when other than default namespace' do
+      subject(:result) { described_class::Policy(policy_class, rule, name: 'custom')[:task].call(ctx, **flow_options) }
+
+      before do
+        allow(policy_class).to receive_message_chain(:new, rule).and_return(true)
+      end
+
+      it 'is put policy in right namespace' do
+        expect(result[0]).to eq(Trailblazer::Activity::Right)
+        expect(result[1][0][:'macro.policy.custom']).to be_instance_of(RSpec::Mocks::Double)
+        expect(result[1][0][:'macro.policy.custom']).to be_respond_to(rule)
+        expect(result[1][0][:'macro.policy.default']).not_to be_present
+      end
+    end
+  end
+end