Refactor `has_secure_password` to extract dedicated attribute module

Follow up of #26764 and #35700.

And add test case for #35700.

activemodel/lib/active_model/secure_password.rb

@@ -69,42 +69,7 @@ module ActiveModel
           raise
         end
 
-        mod = Module.new do
-          attr_reader attribute
-
-          define_method("#{attribute}=") do |unencrypted_password|
-            if unencrypted_password.nil?
-              self.send("#{attribute}_digest=", nil)
-            elsif !unencrypted_password.empty?
-              instance_variable_set("@#{attribute}", unencrypted_password)
-              cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine.cost
-              self.send("#{attribute}_digest=", BCrypt::Password.create(unencrypted_password, cost: cost))
-            end
-          end
-
-          define_method("#{attribute}_confirmation=") do |unencrypted_password|
-            instance_variable_set("@#{attribute}_confirmation", unencrypted_password)
-          end
-
-          # Returns +self+ if the password is correct, otherwise +false+.
-          #
-          #   class User < ActiveRecord::Base
-          #     has_secure_password validations: false
-          #   end
-          #
-          #   user = User.new(name: 'david', password: 'mUc3m00RsqyRe')
-          #   user.save
-          #   user.authenticate_password('notright')      # => false
-          #   user.authenticate_password('mUc3m00RsqyRe') # => user
-          define_method("authenticate_#{attribute}") do |unencrypted_password|
-            attribute_digest = send("#{attribute}_digest")
-            BCrypt::Password.new(attribute_digest).is_password?(unencrypted_password) && self
-          end
-
-          alias_method :authenticate, :authenticate_password if attribute == :password
-        end
-
-        include mod
+        include InstanceMethodsOnActivation.new(attribute)
 
         if validations
           include ActiveModel::Validations
@@ -122,5 +87,42 @@ module ActiveModel
         end
       end
     end
+
+    class InstanceMethodsOnActivation < Module
+      def initialize(attribute)
+        attr_reader attribute
+
+        define_method("#{attribute}=") do |unencrypted_password|
+          if unencrypted_password.nil?
+            self.send("#{attribute}_digest=", nil)
+          elsif !unencrypted_password.empty?
+            instance_variable_set("@#{attribute}", unencrypted_password)
+            cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST : BCrypt::Engine.cost
+            self.send("#{attribute}_digest=", BCrypt::Password.create(unencrypted_password, cost: cost))
+          end
+        end
+
+        define_method("#{attribute}_confirmation=") do |unencrypted_password|
+          instance_variable_set("@#{attribute}_confirmation", unencrypted_password)
+        end
+
+        # Returns +self+ if the password is correct, otherwise +false+.
+        #
+        #   class User < ActiveRecord::Base
+        #     has_secure_password validations: false
+        #   end
+        #
+        #   user = User.new(name: 'david', password: 'mUc3m00RsqyRe')
+        #   user.save
+        #   user.authenticate_password('notright')      # => false
+        #   user.authenticate_password('mUc3m00RsqyRe') # => user
+        define_method("authenticate_#{attribute}") do |unencrypted_password|
+          attribute_digest = send("#{attribute}_digest")
+          BCrypt::Password.new(attribute_digest).is_password?(unencrypted_password) && self
+        end
+
+        alias_method :authenticate, :authenticate_password if attribute == :password
+      end
+    end
   end
 end

activemodel/test/cases/secure_password_test.rb

@@ -184,6 +184,20 @@ class SecurePasswordTest < ActiveModel::TestCase
     assert_nil @existing_user.password_digest
   end
 
+  test "override secure password attribute" do
+    assert_nil @user.password_called
+
+    @user.password = "secret"
+
+    assert_equal "secret", @user.password
+    assert_equal 1, @user.password_called
+
+    @user.password = "terces"
+
+    assert_equal "terces", @user.password
+    assert_equal 2, @user.password_called
+  end
+
   test "authenticate" do
     @user.password = "secret"
     @user.recovery_password = "42password"

activemodel/test/models/user.rb

@@ -10,4 +10,11 @@ class User
   has_secure_password :recovery_password, validations: false
 
   attr_accessor :password_digest, :recovery_password_digest
+  attr_accessor :password_called
+
+  def password=(unencrypted_password)
+    self.password_called ||= 0
+    self.password_called += 1
+    super
+  end
 end