Show object ids in scaffold pages when displaying referenced objects

Resolve Issue#29200

When scaffolding a model that references another model the
generated show and index html pages display the object directly
on the page. Basically, it just shows a memory address. That is
not very helpful. In this commit we show the object's id rather
than the memory address.

This updates the scaffold templates and the json builder files.

railties/CHANGELOG.md

@@ -1,3 +1,8 @@
+*  Use Ids instead of memory addresses when displaying references in scaffold views
+    Fixes #29200.
+
+    *Rasesh Patel*
+
 *   Adds support for multiple databases to `rails db:migrate:status`.
     Subtasks are also added to get the status of individual databases (eg. `rails db:migrate:status:animals`).
 

railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt

@@ -16,7 +16,7 @@
     <%% @<%= plural_table_name %>.each do |<%= singular_table_name %>| %>
       <tr>
 <% attributes.reject(&:password_digest?).each do |attribute| -%>
-        <td><%%= <%= singular_table_name %>.<%= attribute.name %> %></td>
+        <td><%%= <%= singular_table_name %>.<%= attribute.column_name %> %></td>
 <% end -%>
         <td><%%= link_to 'Show', <%= model_resource_name %> %></td>
         <td><%%= link_to 'Edit', edit_<%= singular_route_name %>_path(<%= singular_table_name %>) %></td>

railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt

@@ -3,7 +3,7 @@
 <% attributes.reject(&:password_digest?).each do |attribute| -%>
 <p>
   <strong><%= attribute.human_name %>:</strong>
-  <%%= @<%= singular_table_name %>.<%= attribute.name %> %>
+  <%%= @<%= singular_table_name %>.<%= attribute.column_name %> %>
 </p>
 
 <% end -%>

railties/test/generators/scaffold_generator_test.rb

@@ -435,8 +435,8 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
     end
   end
 
-  def test_scaffold_generator_belongs_to
-    run_generator ["account", "name", "currency:belongs_to"]
+  def test_scaffold_generator_belongs_to_and_references
+    run_generator ["account", "name", "currency:belongs_to", "user:references"]
 
     assert_file "app/models/account.rb", /belongs_to :currency/
 
@@ -449,7 +449,7 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
 
     assert_file "app/controllers/accounts_controller.rb" do |content|
       assert_instance_method :account_params, content do |m|
-        assert_match(/permit\(:name, :currency_id\)/, m)
+        assert_match(/permit\(:name, :currency_id, :user_id\)/, m)
       end
     end
 
@@ -457,6 +457,16 @@ class ScaffoldGeneratorTest < Rails::Generators::TestCase
       assert_match(/^\W{4}<%= form\.text_field :name %>/, content)
       assert_match(/^\W{4}<%= form\.text_field :currency_id %>/, content)
     end
+
+    assert_file "app/views/accounts/index.html.erb" do |content|
+      assert_match(/^\W{8}<td><%= account\.name %><\/td>/, content)
+      assert_match(/^\W{8}<td><%= account\.user_id %><\/td>/, content)
+    end
+
+    assert_file "app/views/accounts/show.html.erb" do |content|
+      assert_match(/^\W{2}<%= @account\.name %>/, content)
+      assert_match(/^\W{2}<%= @account\.user_id %>/, content)
+    end
   end
 
   def test_scaffold_generator_database