copy_attribute_definitions uses type_for_attribute, fallback_to_model_values checks against original_attributes_hash

.rubocop.yml

@@ -6,3 +6,7 @@ Style/StringLiterals:
 
 Style/StringLiteralsInInterpolation:
   EnforcedStyle: double_quotes
+
+Layout/LineLength:
+  Exclude:
+    - test/**/*

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    trenchcoat (0.1.0)
+    trenchcoat (0.2.0)
       activemodel (>= 7.0)
       activerecord (>= 7.0)
       activesupport (>= 7.0)

lib/trenchcoat.rb

@@ -8,9 +8,9 @@ module Trenchcoat
   module Model
     extend ActiveSupport::Concern
 
-    def fallback_to_model_values(model:, attributes:)
-      attributes.each do |attribute|
-        next if send(attribute)
+    def fallback_to_model_values(model:, attributes_to_check:, original_attributes_hash:)
+      attributes_to_check.each do |attribute|
+        next if original_attributes_hash.with_indifferent_access.key?(attribute)
 
         send(:"#{attribute}=", model.public_send(attribute))
       end
@@ -22,7 +22,7 @@ def copy_attribute_definitions(model_class:, attributes:)
 
         attributes.each do |attribute_name|
           column = columns.fetch(attribute_name)
-          attribute column.name, column.type, default: column.default
+          attribute column.name, model_class.type_for_attribute(attribute_name), default: column.default
         end
       end
 

lib/trenchcoat/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Trenchcoat
-  VERSION = "0.1.0"
+  VERSION = "0.2.0"
 end

test/test_helper.rb

@@ -10,7 +10,7 @@
 ActiveRecord::Schema.define do
   create_table :posts do |t|
     t.string :title, null: false
-    t.text :body, null: false
+    t.text :body, null: false, default: "It was a dark and stormy night"
     t.datetime :published_at
   end
 end

test/test_trenchcoat.rb

@@ -18,10 +18,9 @@ class CustomForm
 
       attr_accessor :post
 
-      copy_attribute_definitions(model_class: Post, attributes: %i[title published_at])
+      copy_attribute_definitions(model_class: Post, attributes: %i[title body published_at])
       quack_like(model_instance_attr: :post)
 
-      attribute :body, :string # has to be manually defined because there is not a Text type for ActiveModel by default
       attribute :is_published, :boolean, default: false
       alias is_published? is_published
 
@@ -33,8 +32,11 @@ def initialize(attributes = {})
         published_at
 
         self.post = Post.new if post.blank?
-
-        fallback_to_model_values(model: post, attributes: %i[title body published_at])
+        fallback_to_model_values(
+          model: post,
+          attributes_to_check: %i[title body published_at],
+          original_attributes_hash: attributes
+        )
 
         return if attributes.key?(:is_published)
 
@@ -70,7 +72,7 @@ def normalize_published_at
 
       assert_equal true, form.post.new_record?
       assert_nil form.title
-      assert_nil form.body
+      assert_equal "It was a dark and stormy night", form.body
       assert_nil form.published_at
       assert_equal false, form.is_published
     end
@@ -86,7 +88,7 @@ def normalize_published_at
       assert_equal true, form.is_published
     end
 
-    test "fallback_to_model_values: params given, falls back to model instance if falsey parameter" do
+    test "fallback_to_model_values: params given, falls back to model instance if original_attributes_hash did not include parameter" do
       time = Time.utc(2021, 2, 2)
       post = Post.create!(title: "A Post", body: "Post Content")
       form = CustomForm.new(post: post, title: "Hello", published_at: time, is_published: "1")