@@ -134,5 +134,9 @@ class UserRolesControllerTest < ActionController::TestCase
     end
     assert_redirected_to user_path(target_user.display_name)
     assert_equal "The string `no_such_role' is not a valid role.", flash[:error]
+
+    # Revoking administrator role from current user should fail
+    post :revoke, :params => { :display_name => administrator_user.display_name, :role => "administrator" }
+    assert_redirected_to user_path(administrator_user.display_name)
   end
 end
require "test_helper"

class UserRolesControllerTest < ActionController::TestCase
  ##
  # test all routes which lead to this controller
  def test_routes
    assert_routing(
      { :path => "/user/username/role/rolename/grant", :method => :post },
      { :controller => "user_roles", :action => "grant", :display_name => "username", :role => "rolename" }
    )
    assert_routing(
      { :path => "/user/username/role/rolename/revoke", :method => :post },
      { :controller => "user_roles", :action => "revoke", :display_name => "username", :role => "rolename" }
    )
  end

  ##
  # test the grant action
  def test_grant
    target_user = create(:user)
    normal_user = create(:user)
    administrator_user = create(:administrator_user)
    super_user = create(:super_user)

    # Granting should fail when not logged in
    post :grant, :params => { :display_name => target_user.display_name, :role => "moderator" }
    assert_response :forbidden

    # Login as an unprivileged user
    session[:user] = normal_user.id

    # Granting should still fail
    post :grant, :params => { :display_name => target_user.display_name, :role => "moderator" }
    assert_redirected_to user_path(target_user.display_name)
    assert_equal "Only administrators can perform user role management, and you are not an administrator.", flash[:error]

    # Login as an administrator
    session[:user] = administrator_user.id

    UserRole::ALL_ROLES.each do |role|
      # Granting a role to a non-existent user should fail
      assert_difference "UserRole.count", 0 do
        post :grant, :params => { :display_name => "non_existent_user", :role => role }
      end
      assert_response :not_found
      assert_template "user/no_such_user"
      assert_select "h1", "The user non_existent_user does not exist"

      # Granting a role to a user that already has it should fail
      assert_no_difference "UserRole.count" do
        post :grant, :params => { :display_name => super_user.display_name, :role => role }
      end
      assert_redirected_to user_path(super_user.display_name)
      assert_equal "The user already has role #{role}.", flash[:error]

      # Granting a role to a user that doesn't have it should work...
      assert_difference "UserRole.count", 1 do
        post :grant, :params => { :display_name => target_user.display_name, :role => role }
      end
      assert_redirected_to user_path(target_user.display_name)

      # ...but trying a second time should fail
      assert_no_difference "UserRole.count" do
        post :grant, :params => { :display_name => target_user.display_name, :role => role }
      end
      assert_redirected_to user_path(target_user.display_name)
      assert_equal "The user already has role #{role}.", flash[:error]
    end

    # Granting a non-existent role should fail
    assert_difference "UserRole.count", 0 do
      post :grant, :params => { :display_name => target_user.display_name, :role => "no_such_role" }
    end
    assert_redirected_to user_path(target_user.display_name)
    assert_equal "The string `no_such_role' is not a valid role.", flash[:error]
  end

  ##
  # test the revoke action
  def test_revoke
    target_user = create(:user)
    normal_user = create(:user)
    administrator_user = create(:administrator_user)
    super_user = create(:super_user)

    # Revoking should fail when not logged in
    post :revoke, :params => { :display_name => target_user.display_name, :role => "moderator" }
    assert_response :forbidden

    # Login as an unprivileged user
    session[:user] = normal_user.id

    # Revoking should still fail
    post :revoke, :params => { :display_name => target_user.display_name, :role => "moderator" }
    assert_redirected_to user_path(target_user.display_name)
    assert_equal "Only administrators can perform user role management, and you are not an administrator.", flash[:error]

    # Login as an administrator
    session[:user] = administrator_user.id

    UserRole::ALL_ROLES.each do |role|
      # Removing a role from a non-existent user should fail
      assert_difference "UserRole.count", 0 do
        post :revoke, :params => { :display_name => "non_existent_user", :role => role }
      end
      assert_response :not_found
      assert_template "user/no_such_user"
      assert_select "h1", "The user non_existent_user does not exist"

      # Removing a role from a user that doesn't have it should fail
      assert_no_difference "UserRole.count" do
        post :revoke, :params => { :display_name => target_user.display_name, :role => role }
      end
      assert_redirected_to user_path(target_user.display_name)
      assert_equal "The user does not have role #{role}.", flash[:error]

      # Removing a role from a user that has it should work...
      assert_difference "UserRole.count", -1 do
        post :revoke, :params => { :display_name => super_user.display_name, :role => role }
      end
      assert_redirected_to user_path(super_user.display_name)

      # ...but trying a second time should fail
      assert_no_difference "UserRole.count" do
        post :revoke, :params => { :display_name => super_user.display_name, :role => role }
      end
      assert_redirected_to user_path(super_user.display_name)
      assert_equal "The user does not have role #{role}.", flash[:error]
    end

    # Revoking a non-existent role should fail
    assert_difference "UserRole.count", 0 do
      post :revoke, :params => { :display_name => target_user.display_name, :role => "no_such_role" }
    end
    assert_redirected_to user_path(target_user.display_name)
    assert_equal "The string `no_such_role' is not a valid role.", flash[:error]
  end
end

Can we assert that the flash message is shown here... I think there some examples of doing it in other tests.