Restrict logins to employees in staging

as inferred from the email domain, which must be "@37signals.com" or
"@basecamp.com".

saas/lib/fizzy/saas/authorization.rb

@@ -0,0 +1,28 @@
+module Fizzy
+  module Saas
+    module Authorization
+      module Controller
+        extend ActiveSupport::Concern
+
+        included do
+          before_action :ensure_only_employees_can_access_non_production_remote_environments, if: :authenticated?
+        end
+
+        private
+          def ensure_only_employees_can_access_non_production_remote_environments
+            head :forbidden if Rails.env.staging? && !Current.identity.employee?
+          end
+      end
+
+      module Identity
+        extend ActiveSupport::Concern
+
+        EMPLOYEE_DOMAINS = ["@37signals.com", "@basecamp.com"].freeze
+
+        def employee?
+          email_address.end_with?(*EMPLOYEE_DOMAINS)
+        end
+      end
+    end
+  end
+end

saas/lib/fizzy/saas/engine.rb

@@ -1,5 +1,6 @@
 require_relative "transaction_pinning"
 require_relative "signup"
+require_relative "authorization"
 require_relative "../../rails_ext/active_record_tasks_database_tasks.rb"
 
 module Fizzy
@@ -112,6 +113,9 @@ module Fizzy
           ::Object.send(:remove_const, const_name) if ::Object.const_defined?(const_name)
           ::Object.const_set const_name, Subscription.const_get(short_name, false)
         end
+
+        ::Authorization.include Fizzy::Saas::Authorization::Controller
+        ::Identity.include Fizzy::Saas::Authorization::Identity
       end
     end
   end

saas/test/controllers/non_production_remote_access_test.rb

@@ -0,0 +1,56 @@
+require "test_helper"
+
+class NonProductionRemoteAccessTest < ActionDispatch::IntegrationTest
+  test "employee can access in staging environment" do
+    assert_predicate identities(:david), :employee?
+
+    sign_in_as :david
+
+    Rails.stubs(:env).returns(ActiveSupport::EnvironmentInquirer.new("staging"))
+    get cards_path
+    assert_response :success
+  end
+
+  test "non-employee cannot access in staging environment" do
+    identities(:jz).update!(email_address: "david@example.com")
+    assert_not_predicate identities(:jz), :employee?
+
+    sign_in_as :jz
+
+    Rails.stubs(:env).returns(ActiveSupport::EnvironmentInquirer.new("staging"))
+    get cards_path
+    assert_response :forbidden
+  end
+
+  test "non-employee can access in production environment" do
+    identities(:jz).update!(email_address: "david@example.com")
+    assert_not_predicate identities(:jz), :employee?
+
+    sign_in_as :jz
+
+    Rails.stubs(:env).returns(ActiveSupport::EnvironmentInquirer.new("production"))
+    get cards_path
+    assert_response :success
+  end
+
+  test "non-employee can access in beta environment" do
+    identities(:jz).update!(email_address: "david@example.com")
+    assert_not_predicate identities(:jz), :employee?
+
+    sign_in_as :jz
+
+    Rails.stubs(:env).returns(ActiveSupport::EnvironmentInquirer.new("beta"))
+    get cards_path
+    assert_response :success
+  end
+
+  test "non-employee can access in local environment" do
+    identities(:jz).update!(email_address: "david@example.com")
+    assert_not_predicate identities(:jz), :employee?
+
+    sign_in_as :jz
+
+    get cards_path
+    assert_response :success
+  end
+end

saas/test/models/identity_test.rb

@@ -0,0 +1,18 @@
+require "test_helper"
+
+class Fizzy::Saas::IdentityTest < ActiveSupport::TestCase
+  test "#employee? returns true for 37signals.com domains" do
+    identity = Identity.new(email_address: "mike@37signals.com")
+    assert_predicate identity, :employee?
+  end
+
+  test "#employee? returns true for basecamp.com domains" do
+    identity = Identity.new(email_address: "mike@basecamp.com")
+    assert_predicate identity, :employee?
+  end
+
+  test "#employee? returns false for other domains" do
+    identity = Identity.new(email_address: "mike@example.com")
+    assert_not_predicate identity, :employee?
+  end
+end