From fb42c492a7eff58f45867ea50440d938648cdb48 Mon Sep 17 00:00:00 2001
From: Jon McCartie <jon@mccartie.com>
Date: Thu, 24 Sep 2015 21:57:40 -0700
Subject: [PATCH] Set active_record config for always creating uuids in
 generators

---
 activerecord/CHANGELOG.md                           |  7 +++++++
 .../migration/templates/create_table_migration.rb   |  2 +-
 railties/lib/rails/generators/migration.rb          |  5 +++++
 .../test/generators/migration_generator_test.rb     | 13 +++++++++++++
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index ed861dc4d6..9f347e735c 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,10 @@
+*   Add ability to default to `uuid` as primary key when generating database migrations
+
+    Set `Rails.application.config.active_record.primary_key = :uuid`
+    or `config.active_record.primary_key = :uuid` in config/application.rb
+
+    *Jon McCartie*
+
 *   Qualify column name inserted by `group` in calculation
 
     Giving `group` an unqualified column name now works, even if the relation
diff --git a/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb b/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
index 5b3e57dcf6..4a7deb3c75 100644
--- a/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
+++ b/activerecord/lib/rails/generators/active_record/migration/templates/create_table_migration.rb
@@ -1,6 +1,6 @@
 class <%= migration_class_name %> < ActiveRecord::Migration
   def change
-    create_table :<%= table_name %> do |t|
+    create_table :<%= table_name %><%= id_kind %> do |t|
 <% attributes.each do |attribute| -%>
 <% if attribute.password_digest? -%>
       t.string :password_digest<%= attribute.inject_options %>
diff --git a/railties/lib/rails/generators/migration.rb b/railties/lib/rails/generators/migration.rb
index 87f2e1d42b..a755471a4b 100644
--- a/railties/lib/rails/generators/migration.rb
+++ b/railties/lib/rails/generators/migration.rb
@@ -30,6 +30,11 @@ module Rails
         end
       end
 
+      def id_kind
+        kind = Rails.application.config.active_record.primary_key rescue nil
+        ", id: :#{kind}" if kind
+      end
+
       def create_migration(destination, data, config = {}, &block)
         action Rails::Generators::Actions::CreateMigration.new(self, destination, block || data.to_s, config)
       end
diff --git a/railties/test/generators/migration_generator_test.rb b/railties/test/generators/migration_generator_test.rb
index 57bc220558..a7f807b747 100644
--- a/railties/test/generators/migration_generator_test.rb
+++ b/railties/test/generators/migration_generator_test.rb
@@ -221,6 +221,19 @@ class MigrationGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_add_uuid_to_create_table_migration
+    previous_value = Rails.application.config.active_record.primary_key
+    Rails.application.config.active_record.primary_key = :uuid
+    run_generator ["create_books"]
+    assert_migration "db/migrate/create_books.rb" do |content|
+      assert_method :change, content do |change|
+        assert_match(/create_table :books, id: :uuid/, change)
+      end
+    end
+
+    Rails.application.config.active_record.primary_key = previous_value
+  end
+
   def test_should_create_empty_migrations_if_name_not_start_with_add_or_remove_or_create
     migration = "delete_books"
     run_generator [migration, "title:string", "content:text"]