add warning when redefining controller method

Author: aarek

lib/active_admin/resource_dsl.rb

@@ -131,7 +131,7 @@ def csv(options = {}, &block)
     # action.
     #
     def action(set, name, options = {}, &block)
-      raise ArgumentError, "method #{name} already defined" if controller.method_defined?(name)
+      warn "Warning: method `#{name}` already defined" if controller.method_defined?(name)
 
       set << ControllerAction.new(name, options)
       title = options.delete(:title)

spec/unit/action_builder_spec.rb

@@ -1,156 +1,157 @@
 require 'rails_helper'
 
 RSpec.describe 'defining actions from registration blocks', type: :controller do
-  context 'when method with given name does not exist' do
-    let(:klass){ Admin::PostsController }
+  let(:klass){ Admin::PostsController }
 
-    before do
-      load_resources { action! }
+  before do
+    load_resources { action! }
 
-      @controller = klass.new
-    end
+    @controller = klass.new
+  end
 
-    describe 'creates a member action' do
-      after(:each) do
-        klass.clear_member_actions!
-      end
+  describe 'creates a member action' do
+    after(:each) do
+      klass.clear_member_actions!
+    end
 
-      context 'with a block' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            member_action :comment do
-              # Do nothing
-            end
+    context 'with a block' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          member_action :comment do
+            # Do nothing
           end
         end
+      end
 
-        it 'should create a new public instance method' do
-          expect(klass.public_instance_methods.collect(&:to_s)).to include('comment')
-        end
+      it 'should create a new public instance method' do
+        expect(klass.public_instance_methods.collect(&:to_s)).to include('comment')
+      end
 
-        it 'should add itself to the member actions config' do
-          expect(klass.active_admin_config.member_actions.size).to eq 1
-        end
+      it 'should add itself to the member actions config' do
+        expect(klass.active_admin_config.member_actions.size).to eq 1
+      end
 
-        it 'should create a new named route' do
-          expect(Rails.application.routes.url_helpers.methods.collect(&:to_s)).to include('comment_admin_post_path')
-        end
+      it 'should create a new named route' do
+        expect(Rails.application.routes.url_helpers.methods.collect(&:to_s)).to include('comment_admin_post_path')
       end
+    end
 
-      context 'without a block' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            member_action :comment
-          end
+    context 'without a block' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          member_action :comment
         end
+      end
 
-        it 'should still generate a new empty action' do
-          expect(klass.public_instance_methods.collect(&:to_s)).to include('comment')
-        end
+      it 'should still generate a new empty action' do
+        expect(klass.public_instance_methods.collect(&:to_s)).to include('comment')
       end
+    end
 
-      context 'with :title' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            member_action :comment, title: 'My Awesome Comment' do
-              render json: {a: 2}
-            end
+    context 'with :title' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          member_action :comment, title: 'My Awesome Comment' do
+            render json: {a: 2}
           end
         end
+      end
 
-        it 'sets the page title' do
-          params = {id: 1}
-          params = {params: params} if ActiveAdmin::Dependency.rails5?
-          get :comment, params
+      it 'sets the page title' do
+        params = {id: 1}
+        params = {params: params} if ActiveAdmin::Dependency.rails5?
+        get :comment, params
 
-          expect(controller.instance_variable_get(:@page_title)).to eq 'My Awesome Comment'
-        end
+        expect(controller.instance_variable_get(:@page_title)).to eq 'My Awesome Comment'
       end
     end
+  end
 
-    describe 'creates a collection action' do
-      after(:each) do
-        klass.clear_collection_actions!
-      end
+  describe 'creates a collection action' do
+    after(:each) do
+      klass.clear_collection_actions!
+    end
 
-      context 'with a block' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            collection_action :comments do
-              # Do nothing
-            end
+    context 'with a block' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          collection_action :comments do
+            # Do nothing
           end
         end
+      end
 
-        it 'should create a public instance method' do
-          expect(klass.public_instance_methods.collect(&:to_s)).to include('comments')
-        end
+      it 'should create a public instance method' do
+        expect(klass.public_instance_methods.collect(&:to_s)).to include('comments')
+      end
 
-        it 'should add itself to the member actions config' do
-          expect(klass.active_admin_config.collection_actions.size).to eq 1
-        end
+      it 'should add itself to the member actions config' do
+        expect(klass.active_admin_config.collection_actions.size).to eq 1
+      end
 
-        it 'should create a named route' do
-          expect(Rails.application.routes.url_helpers.methods.collect(&:to_s)).to include('comments_admin_posts_path')
-        end
+      it 'should create a named route' do
+        expect(Rails.application.routes.url_helpers.methods.collect(&:to_s)).to include('comments_admin_posts_path')
       end
+    end
 
-      context 'without a block' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            collection_action :comments
-          end
+    context 'without a block' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          collection_action :comments
         end
+      end
 
-        it 'should still generate a new empty action' do
-          expect(klass.public_instance_methods.collect(&:to_s)).to include('comments')
-        end
+      it 'should still generate a new empty action' do
+        expect(klass.public_instance_methods.collect(&:to_s)).to include('comments')
       end
+    end
 
-      context 'with :title' do
-        let(:action!) do
-          ActiveAdmin.register Post do
-            collection_action :comments, title: 'My Awesome Comments' do
-              render json: {a: 2}
-            end
+    context 'with :title' do
+      let(:action!) do
+        ActiveAdmin.register Post do
+          collection_action :comments, title: 'My Awesome Comments' do
+            render json: {a: 2}
           end
         end
+      end
 
-        it 'sets the page title' do
-          get :comments
+      it 'sets the page title' do
+        get :comments
 
-          expect(controller.instance_variable_get(:@page_title)).to eq 'My Awesome Comments'
-        end
+        expect(controller.instance_variable_get(:@page_title)).to eq 'My Awesome Comments'
       end
     end
   end
 
   context 'when method with given name is already defined' do
+    around :each do |example|
+      original_stderr = $stderr
+      $stderr = StringIO.new
+      example.run
+      $stderr = original_stderr
+    end
+
     describe 'defining member action' do
-      subject do
-        load_resources do
-          ActiveAdmin.register Post do
-            member_action :process
-          end
+      let :action! do
+        ActiveAdmin.register Post do
+          member_action :process
         end
       end
 
-      it 'raises error' do
-        expect { subject }.to raise_error(ArgumentError)
+      it 'writes warning to $stderr' do
+        expect($stderr.string).to include('Warning: method `process` already defined')
       end
     end
 
     describe 'defining collection action' do
-      subject do
-        load_resources do
-          ActiveAdmin.register Post do
-            collection_action :process
-          end
+      let :action! do
+        ActiveAdmin.register Post do
+          collection_action :process
         end
       end
 
-      it 'raises error' do
-        expect { subject }.to raise_error(ArgumentError)
+      it 'writes warning to $stderr' do
+        expect($stderr.string).to include('Warning: method `process` already defined')
       end
     end
   end