fixes disabling of features via admin interface

app/models/setting.rb

@@ -5,13 +5,12 @@ class Setting < ActiveRecord::Base
 
   class << self
     def [](key)
-      where(key: key).pluck(:value).first
+      where(key: key).pluck(:value).first.presence
     end
 
     def []=(key, value)
       setting = where(key: key).first || new(key: key)
-      setting.value = value
+      setting.value = value.presence
-      setting.value = nil if setting.value == false
       setting.save!
       value
     end

spec/features/admin/feature_flags_spec.rb

@@ -0,0 +1,61 @@
+require 'rails_helper'
+
+feature 'Admin feature flags' do
+
+  background do
+    login_as(create(:administrator).user)
+  end
+
+  scenario 'Enabled features are listed on menu' do
+    visit admin_root_path
+
+    within('#admin_menu') do
+      expect(page).to have_link "Spending proposals"
+      expect(page).to have_link "Hidden debates"
+    end
+  end
+
+  scenario 'Disable a feature' do
+    setting_id = Setting.find_by(key: 'feature.spending_proposals').id
+
+    visit admin_settings_path
+
+    within("#edit_setting_#{setting_id}") do
+      fill_in "setting_#{setting_id}", with: ''
+      click_button 'Update'
+    end
+
+    visit admin_root_path
+
+    within('#admin_menu') do
+      expect(page).not_to have_link "Spending proposals"
+    end
+
+    expect{ visit spending_proposals_path }.to raise_exception(FeatureFlags::FeatureDisabled)
+    expect{ visit admin_spending_proposals_path }.to raise_exception(FeatureFlags::FeatureDisabled)
+  end
+
+  scenario 'Enable a disabled feature' do
+    Setting['feature.spending_proposals'] = nil
+    setting_id = Setting.find_by(key: 'feature.spending_proposals').id
+
+    visit admin_root_path
+
+    within('#admin_menu') do
+      expect(page).not_to have_link "Spending proposals"
+    end
+
+    visit admin_settings_path
+
+    within("#edit_setting_#{setting_id}") do
+      fill_in "setting_#{setting_id}", with: 'true'
+      click_button 'Update'
+    end
+
+    visit admin_root_path
+
+    within('#admin_menu') do
+      expect(page).to have_link "Spending proposals"
+    end
+  end
+end