#201 | Enhanced tenanted and untenanted associations

lib/active_record/tenanted/cross_tenant_associations.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module Tenanted
+    module CrossTenantAssociations
+      extend ActiveSupport::Concern
+
+      class_methods do
+        # I think we can have more configs later
+        def cross_tenant_config(**config)
+          @cross_tenant_config = config
+        end
+
+        def get_cross_tenant_config
+          @cross_tenant_config ||= {}
+        end
+
+        def has_one(name, scope = nil, **options)
+          define_enhanced_association(:has_one, name, scope, **options)
+        end
+
+        def has_many(name, scope = nil, **options)
+          define_enhanced_association(:has_many, name, scope, **options)
+        end
+
+        private
+          # For now association methods are identical
+          def define_enhanced_association(association_type, name, scope, **options)
+            config = get_cross_tenant_config
+            tenant_column = config[:tenant_column] || :tenant_id
+            custom_options = options.merge(tenant_column: tenant_column)
+
+            enhanced_scope = enhance_cross_tenant_association(name, scope, custom_options)
+            method(association_type).super_method.call(name, enhanced_scope, **options)
+          end
+
+          def enhance_cross_tenant_association(name, scope, options)
+            target_class = options[:class_name]&.safe_constantize || name.to_s.classify.safe_constantize
+
+            return scope unless target_class
+
+            unless target_class.tenanted?
+              tenant_column = options[:tenant_column]
+
+              return ->(record) {
+                base_scope = scope ? target_class.instance_exec(&scope) : target_class.all
+                base_scope.where(tenant_column => record.tenant)
+              }
+            end
+
+            scope
+          end
+      end
+    end
+  end
+end

lib/active_record/tenanted/subtenant.rb

@@ -6,6 +6,8 @@ module Subtenant
       extend ActiveSupport::Concern
 
       class_methods do
+        include CrossTenantAssociations::ClassMethods
+
         def tenanted?
           true
         end

lib/active_record/tenanted/tenant.rb

@@ -85,6 +85,8 @@ def to_s
       CONNECTION_POOL_CREATION_LOCK = Thread::Mutex.new # :nodoc:
 
       class_methods do
+        include CrossTenantAssociations::ClassMethods
+
         def tenanted?
           true
         end
@@ -228,6 +230,7 @@ def _create_tenanted_pool(schema_version_check: true) # :nodoc:
           pool
         end
 
+
         private
           def retrieve_connection_pool(strict:)
             role = current_role

test/unit/tenant_test.rb

@@ -519,6 +519,206 @@
     end
   end
 
+  describe "cross-tenant associations" do
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.has_one :announcement
+        Announcement.belongs_to :user
+      end
+
+      test "has_one automatically scopes by tenant_id" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Foo announcement", tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_nil user.announcement
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcement
+          assert_equal "Foo announcement", user.announcement.message
+        end
+      end
+    end
+
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.has_many :announcements
+        Announcement.belongs_to :user
+      end
+
+      test "has_many automatically scopes by tenant_id" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Foo announcement", tenant_id: "foo", user: user)
+          Announcement.create!(message: "Another Foo announcement", tenant_id: "foo", user: user)
+          Announcement.create!(message: "Yet another Foo announcement", tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_equal 0, user.announcements.count
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcements
+          assert_equal 3, user.announcements.count
+          assert_equal "Foo announcement", user.announcements.first.message
+          assert_equal "Another Foo announcement", user.announcements.second.message
+          assert_equal "Yet another Foo announcement", user.announcements.third.message
+        end
+      end
+    end
+  end
+
+  describe "cross-tenant associations with scope" do
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.has_one :announcement, -> { where(message: "Special announcement") }
+        Announcement.belongs_to :user
+      end
+
+      test "has_one automatically scopes by tenant_id and scope" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Special announcement", tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_nil user.announcement
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcement
+          assert_equal "Special announcement", user.announcement.message
+        end
+      end
+    end
+
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.has_many :announcements, -> { where(message: "Special announcement") }
+        Announcement.belongs_to :user
+      end
+
+      test "has_many automatically scopes by tenant_id and scope" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Special announcement", tenant_id: "foo", user: user)
+          Announcement.create!(message: "Another announcement", tenant_id: "foo", user: user)
+          Announcement.create!(message: "Yet another announcement", tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_equal 0, user.announcements.count
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcements
+          assert_equal 1, user.announcements.count
+          assert_equal "Special announcement", user.announcements.first.message
+        end
+      end
+    end
+  end
+
+  describe "cross-tenant associations with custom tenant column and class name" do
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :custom_tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.cross_tenant_config(tenant_column: :custom_tenant_id)
+        User.has_one :announcement, class_name: "Announcement"
+        Announcement.belongs_to :user
+      end
+
+      test "has_one automatically scopes by custom tenant id and class name" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Special announcement", custom_tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_nil user.announcement
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcement
+          assert_equal "Special announcement", user.announcement.message
+        end
+      end
+    end
+
+    for_each_scenario do
+      setup do
+        ActiveRecord::Base.connection.add_column :announcements, :custom_tenant_id, :string
+        ActiveRecord::Base.connection.add_column :announcements, :user_id, :integer
+
+        User.cross_tenant_config(tenant_column: :custom_tenant_id)
+        User.has_many :announcements, class_name: "Announcement"
+        Announcement.belongs_to :user
+      end
+
+      test "has_many automatically scopes by custom tenant id and class name" do
+        TenantedApplicationRecord.create_tenant("foo") do
+          user = User.create!(email: "[email protected]")
+          Announcement.create!(message: "Foo announcement", custom_tenant_id: "foo", user: user)
+          Announcement.create!(message: "Another Foo announcement", custom_tenant_id: "foo", user: user)
+          Announcement.create!(message: "Yet another Foo announcement", custom_tenant_id: "foo", user: user)
+        end
+
+        TenantedApplicationRecord.create_tenant("bar") do
+          user = User.create!(email: "[email protected]")
+
+          assert_equal 0, user.announcements.count
+        end
+
+        TenantedApplicationRecord.with_tenant("foo") do
+          user = User.first
+
+          assert_not_nil user.announcements
+          assert_equal 3, user.announcements.count
+          assert_equal "Foo announcement", user.announcements.first.message
+          assert_equal "Another Foo announcement", user.announcements.second.message
+          assert_equal "Yet another Foo announcement", user.announcements.third.message
+        end
+      end
+    end
+  end
 
   describe ".without_tenant" do
     for_each_scenario do