Use JavaScript in tests opening modal dialogs

This way we reproduce the user experience in the tests, and we can make
sure modal dialogs open when we expect it.

spec/system/admin/hidden_comments_spec.rb

@@ -1,7 +1,7 @@
 require "rails_helper"
 
 describe "Admin hidden comments", :admin do
-  scenario "Do not show comments from blocked users" do
+  scenario "Do not show comments from blocked users", :js do
     comment = create(:comment, :hidden, body: "SPAM from SPAMMER")
     proposal = create(:proposal, author: comment.author)
     create(:comment, commentable: proposal, user: comment.author, body: "Good Proposal!")
@@ -11,11 +11,15 @@ describe "Admin hidden comments", :admin do
     expect(page).not_to have_content("Good Proposal!")
 
     visit proposal_path(proposal)
+
     within("#proposal_#{proposal.id}") do
-      click_link "Hide author"
+      accept_confirm { click_link "Hide author" }
     end
 
+    expect(page).to have_current_path debates_path
+
     visit admin_hidden_comments_path
+
     expect(page).not_to have_content("SPAM from SPAMMER")
     expect(page).not_to have_content("Good Proposal!")
   end
@@ -59,11 +63,11 @@ describe "Admin hidden comments", :admin do
     expect(page).not_to have_link("This is SPAM comment on proposal")
   end
 
-  scenario "Restore" do
+  scenario "Restore", :js do
     comment = create(:comment, :hidden, body: "Not really SPAM")
     visit admin_hidden_comments_path
 
-    click_link "Restore"
+    accept_confirm { click_link "Restore" }
 
     expect(page).not_to have_content(comment.body)
 
@@ -119,13 +123,13 @@ describe "Admin hidden comments", :admin do
     expect(page).to have_content("Confirmed comment")
   end
 
-  scenario "Action links remember the pagination setting and the filter" do
+  scenario "Action links remember the pagination setting and the filter", :js do
     allow(Comment).to receive(:default_per_page).and_return(2)
     4.times { create(:comment, :hidden, :with_confirmed_hide) }
 
     visit admin_hidden_comments_path(filter: "with_confirmed_hide", page: 2)
 
-    click_on("Restore", match: :first, exact: true)
+    accept_confirm { click_link "Restore", match: :first, exact: true }
 
     expect(page).to have_current_path(/filter=with_confirmed_hide/)
     expect(page).to have_current_path(/page=2/)