Fix SystemStackError when extending the reload method with Module#pre…

…pend (#457)

For example, when using the master branch of activerecord-multi-tenant, if activerecord-multi-tenant and attr_encrypted are listed in the Gemfile in that order, calling the reload method raises a SystemStackError. This happens because activerecord-multi-tenant extends Active Record’s reload method using prepend, while attr_encrypted extends it using an alias method.

Here’s an example of how extending the same method with both prepend and alias methods in that order can result in a SystemStackError

```
class Hello
  def hello
    'hello'
  end
end

Hello.prepend(Module.new do
  def hello
    super
  end
end)

Hello.class_eval do
  alias orig_hello hello

  def hello
    "#{orig_hello} world"
  end
end

Hello.new.hello #=> SystemStackError
```

However, reversing the order works:

```
class Hello
  def hello
    'hello'
  end
end

Hello.class_eval do
  alias orig_hello hello

  def hello
    "#{orig_hello} world"
  end
end

Hello.prepend(Module.new do
  def hello
    super
  end
end)

Hello.new.hello #=> "hello world"
```

This issue can be resolved by standardizing the method extension to use prepend to avoid conflicts.

lib/attr_encrypted/adapters/active_record.rb

@@ -6,19 +6,18 @@ module Adapters
       module ActiveRecord
         RAILS_VERSION = Gem::Version.new(::ActiveRecord::VERSION::STRING).freeze
 
-        def self.extended(base) # :nodoc:
-          base.class_eval do
-
-            # https://github.com/attr-encrypted/attr_encrypted/issues/68
-            alias_method :reload_without_attr_encrypted, :reload
-            def reload(*args, &block)
-              result = reload_without_attr_encrypted(*args, &block)
-              self.class.attr_encrypted_encrypted_attributes.keys.each do |attribute_name|
-                instance_variable_set("@#{attribute_name}", nil)
-              end
-              result
+        module Reload
+          def reload(...)
+            result = super
+            self.class.attr_encrypted_encrypted_attributes.keys.each do |attribute_name|
+              instance_variable_set("@#{attribute_name}", nil)
             end
+            result
+          end
+        end
 
+        def self.extended(base) # :nodoc:
+          base.class_eval do
             attr_encrypted_options[:encode] = true
 
             class << self
@@ -148,5 +147,6 @@ def method_missing_with_attr_encrypted(method, *args, &block)
   ActiveSupport.on_load(:active_record) do
     extend AttrEncrypted
     extend AttrEncrypted::Adapters::ActiveRecord
+    prepend AttrEncrypted::Adapters::ActiveRecord::Reload
   end
 end