Rails spec

Guidelines for writing a spec file

Model spec

View spec

Helpers

• matcher have_link_for_each_item checks that each item in the given collection has a link to the expected URL (defined in spec/support/integration_spec_helper.rb).
• matcher have_the_right_number_of_links checks that each item in the given collection has the expected number of links (defined in spec/support/integration_spec_helper.rb).
• with_permission PERMISSION_NAME do ... a context manager that enables view testing with the given permission activated (defined in spec/support/integration_spec_helper.rb).
• build_paginated_collection(:factory_name, decorator_class, factory_options, context: decorator_context) creates a collection of decorated objects using factories, with a result similar to what would be created in the controller (defined in spec/support/integration_spec_helper.rb).

Tips

• to simulate a nested route (for example, /parents/:parent_id/objects):

    controller.request.path_parameters[:parent_id] = parent.id
  

Example

Here's an example index view spec, where we want to verify:

• the number of rows in the table
• that each row has a link (accounting for permissions)

require 'spec_helper'

describe "/objects/index", type: :view do
  let(:parent) { assign :parent, create(:parent) }
  let(:context) {
     {
       foo: bar,
       bar: baz
     }
   }
  let(:objects) do
    assign(
      :objects,
      build_paginated_collection(
        :object,
        ObjectDecorator,
        parent: parent,
        context: context
      )
    )
  end

  before(:each) do
    allow(view).to receive(:collection).and_return(objects)
    allow(view).to receive(:current_referential).and_return(parent)
    controller.request.path_parameters[:parent_id] = parent.id
    render
  end

  common_items = ->{
    it do
      should have_link_for_each_item(
        objects,
        "show",
        ->(object) { view.parent_object_path(parent, object) }
      )
    end
    it do
      should have_link_for_each_item(
        objects,
        "foo",
        ->(object) { view.parent_foo_path(parent, object.foo) }
      )
    end
    it do
      should have_link_for_each_item(
        objects,
        "bar",
        ->(object) { view.parent_bar_path(parent, object.bar) }
      )
    end
  }

  common_items.call()
  it { should have_the_right_number_of_links(objects, 3) }

  with_permission "objects.activate" do
    common_items.call()

    it do
      should have_link_for_each_item(
        objects,
        "activate",
        ->(object) { view.activate_parent_object_path(parent, object) }
      )
    end

    it { should have_the_right_number_of_links(objects, 4) }
  end
end

Controller spec

Helpers

• login_user to create a User and authenticate it in the session
• with_permission PERMISSION do ... to add the given permission to the current user in the context of the block

Example

RSpec.describe ObjectController, type: :controller do
  login_user

  let(:parent) { create :parent }
  let(:object) { create :object, parent: parent }

  describe 'PUT deactivate' do
    let(:request){ put :deactivate, id: object.id, parent_id: parent.id }

    it 'should redirect to 403' do
      expect(request).to redirect_to "/403"
    end

    with_permission "foo.bar" do
      it 'returns HTTP success' do
        expect(request).to redirect_to [parent, object]
        expect(object.reload).to be_deactivated
      end
    end
  end

  describe 'PUT activate' do
    let(:request){ put :activate, id: object.id, parent_id: parent.id }

    before(:each) do
      object.deactivate!
    end

    it 'should redirect to 403' do
      expect(request).to redirect_to "/403"
    end

    with_permission "objects.change_status" do
      it 'returns HTTP success' do
        expect(request).to redirect_to [parent, object]
        expect(object.reload).to be_activated
      end
    end
  end
end