Support rails 7.2

rails/rails@e0a55b0

While we do not leverage the `attribute` api, we are strongly influenced by it.
We do not want a default value record, which modifies select(*) calls and others.
We want to add the values to `attribute_type`.

Before
------

The values are stored in `attributes_to_define_after_schema_loads` at class load time,
and in load_schema, are then used to generate entries for `DefaultValue` and `attribute_type`.

After
-----

The values are stored as `ModifyAttribute` entries.
Those values then are used to populate default values and attribute_type on demand.

Our Change
----------

Previous PRs removed arel and uses logic so load_schema only manipulated attribute_type.
Like the rails change, we populate (modify) attribute_type on demand.

Author: kbrock

Gemfile

@@ -2,7 +2,6 @@
 
 source "https://rubygems.org"
 
-gem "activerecord", "~>7.1.5"
 gem "mysql2"
 gem "pg"
 gem "sqlite3", "< 2"

activerecord-virtual_attributes.gemspec

@@ -28,7 +28,7 @@ Gem::Specification.new do |spec|
 
   spec.require_paths = ["lib"]
 
-  spec.add_runtime_dependency "activerecord", "~> 7.1", ">=7.1.5.1"
+  spec.add_runtime_dependency "activerecord", "~> 7.2.2", ">=7.2.2.1"
 
   spec.add_development_dependency "byebug"
   spec.add_development_dependency "database_cleaner-active_record", "~> 2.1"

lib/active_record/virtual_attributes.rb

@@ -87,16 +87,13 @@ def virtual_attribute_names
         end
       end
 
-      private
-
-      def load_schema!
-        super
-
-        virtual_attributes_to_define.each do |name, (type, options)|
-          type = type.call if type.respond_to?(:call)
-          type = ActiveRecord::Type.lookup(type, **options) if type.kind_of?(Symbol)
-
-          define_virtual_attribute(name, type)
+      def attribute_types
+        @attribute_types || super.tap do |hash|
+          virtual_attributes_to_define.each do |name, (type, options)|
+            type = type.call if type.respond_to?(:call)
+            type = ActiveRecord::Type.lookup(type, **options) if type.kind_of?(Symbol)
+            hash[name] = type
+          end
         end
       end