Stub current_user in all component tests

The `sign_in(nil)` method was a bit hard to understand IMHO. After all,
in controller and system tests we don't have to specify no user is
signed in; that's the default behavior.

So we're making it the default behavior for component tests as well.

spec/components/budgets/investments/votes_component_spec.rb

@@ -19,8 +19,6 @@ describe Budgets::Investments::VotesComponent do
       end
 
       it "disables the button to support the investment to unidentified users" do
-        sign_in(nil)
-
         render_inline component
 
         expect(page).to have_button count: 1, disabled: :all

spec/components/budgets/investments_list_component_spec.rb

@@ -7,8 +7,6 @@ describe Budgets::InvestmentsListComponent do
   let(:group)     { create(:budget_group, budget: budget) }
   let(:heading)   { create(:budget_heading, group: group) }
 
-  before { sign_in(nil) }
-
   describe "#investments" do
     let(:component) { Budgets::InvestmentsListComponent.new(budget) }
 

spec/components/budgets/subheader_component_spec.rb

@@ -53,8 +53,6 @@ describe Budgets::SubheaderComponent do
     end
 
     it "and user is not logged in shows links to sign in and sign up" do
-      sign_in(nil)
-
       render_inline Budgets::SubheaderComponent.new(budget)
 
       expect(page).to have_content "To create a new budget investment you must"

spec/components/budgets/supports_info_component_spec.rb

@@ -4,7 +4,6 @@ describe Budgets::SupportsInfoComponent do
   let(:budget) { create(:budget, :selecting) }
   let(:group) { create(:budget_group, budget: budget) }
   let(:component) { Budgets::SupportsInfoComponent.new(budget) }
-  before { sign_in(nil) }
 
   it "renders when the budget is selecting" do
     create(:budget_heading, group: group)

spec/components/machine_learning/comments_summary_component_spec.rb

@@ -7,7 +7,6 @@ describe MachineLearning::CommentsSummaryComponent do
   before do
     Setting["feature.machine_learning"] = true
     Setting["machine_learning.comments_summary"] = true
-    sign_in(nil)
   end
 
   it "is displayed when the setting is enabled" do

spec/components/relationable/related_list_component_spec.rb

@@ -14,8 +14,6 @@ describe Relationable::RelatedListComponent do
     create(:related_content, parent_relationable: proposal,
            child_relationable: machine_proposal,
            machine_learning: true)
-
-    sign_in(nil)
   end
 
   it "displays machine learning and user content when machine learning is enabled" do

spec/spec_helper.rb

@@ -83,6 +83,10 @@ RSpec.configure do |config|
     sign_in(create(:administrator).user)
   end
 
+  config.before(:each, type: :component) do
+    sign_in(nil)
+  end
+
   config.around(:each, :controller, type: :component) do |example|
     with_controller_class(example.metadata[:controller]) { example.run }
   end