Merge pull request #16231 from Envek/type_in_references

* Allow to specify a type for foreign key column in migrations
* unified the docs
* some cleanup in CHANGELOG

6 files changed, 56 insertions, 5 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 6d0a2e13ee..43232443e7 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,14 @@
+*   Allow to specify a type for the foreign key column in `references`
+    and `add_reference`.
+
+    Example:
+
+        change_table :vehicle do |t|
+          t.references :station, type: :uuid
+        end
+
+    *Andrey Novikov*, *Łukasz Sarnacki*
+
 *   `create_join_table` removes a common prefix when generating the join table.
     This matches the existing behavior of HABTM associations.
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 98e6795f10..e44ccb7d81 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -280,12 +280,22 @@ module ActiveRecord
         column(:updated_at, :datetime, options)
       end
 
+      # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
+      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable. The reference column will be an +integer+
+      # by default, the <tt>:type</tt> option can be used to specify a different type.
+      #
+      #  t.references(:user)
+      #  t.references(:user, type: "string")
+      #  t.belongs_to(:supplier, polymorphic: true)
+      #
+      # See SchemaStatements#add_reference
       def references(*args)
         options = args.extract_options!
         polymorphic = options.delete(:polymorphic)
         index_options = options.delete(:index)
+        type = options.delete(:type) || :integer
         args.each do |col|
-          column("#{col}_id", :integer, options)
+          column("#{col}_id", type, options)
           column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
           index(polymorphic ? %w(id type).map { |t| "#{col}_#{t}" } : "#{col}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
         end
@@ -500,11 +510,14 @@ module ActiveRecord
       end
 
       # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
-      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable.
+      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable. The reference column will be an +integer+
+      # by default, the <tt>:type</tt> option can be used to specify a different type.
       #
       #  t.references(:user)
+      #  t.references(:user, type: "string")
       #  t.belongs_to(:supplier, polymorphic: true)
       #
+      # See SchemaStatements#add_reference
       def references(*args)
         options = args.extract_options!
         args.each do |ref_name|
@@ -519,6 +532,7 @@ module ActiveRecord
       #  t.remove_references(:user)
       #  t.remove_belongs_to(:supplier, polymorphic: true)
       #
+      # See SchemaStatements#remove_reference
       def remove_references(*args)
         options = args.extract_options!
         args.each do |ref_name|
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 5814c2b711..10753defc2 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -602,12 +602,18 @@ module ActiveRecord
       end
 
       # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
+      # The reference column is an +integer+ by default, the <tt>:type</tt> option can be used to specify
+      # a different type.
       # <tt>add_reference</tt> and <tt>add_belongs_to</tt> are acceptable.
       #
-      # ====== Create a user_id column
+      # ====== Create a user_id integer column
       #
       #   add_reference(:products, :user)
       #
+      # ====== Create a user_id string column
+      #
+      #   add_reference(:products, :user, type: :string)
+      #
       # ====== Create a supplier_id and supplier_type columns
       #
       #   add_belongs_to(:products, :supplier, polymorphic: true)
@@ -619,7 +625,8 @@ module ActiveRecord
       def add_reference(table_name, ref_name, options = {})
         polymorphic = options.delete(:polymorphic)
         index_options = options.delete(:index)
-        add_column(table_name, "#{ref_name}_id", :integer, options)
+        type = options.delete(:type) || :integer
+        add_column(table_name, "#{ref_name}_id", type, options)
         add_column(table_name, "#{ref_name}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
         add_index(table_name, polymorphic ? %w[id type].map{ |t| "#{ref_name}_#{t}" } : "#{ref_name}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
       end
diff --git a/activerecord/test/cases/adapters/postgresql/uuid_test.rb b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
index d7ff81a382..66006d718f 100644
--- a/activerecord/test/cases/adapters/postgresql/uuid_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/uuid_test.rb
@@ -233,7 +233,7 @@ class PostgresqlUUIDTestInverseOf < ActiveRecord::TestCase
         t.string 'title'
       end
       connection.create_table('pg_uuid_comments', id: :uuid) do |t|
-        t.uuid :uuid_post_id, default: 'uuid_generate_v4()'
+        t.references :uuid_post, type: :uuid
         t.string 'content'
       end
     end
diff --git a/activerecord/test/cases/migration/change_table_test.rb b/activerecord/test/cases/migration/change_table_test.rb
index a6d506b04a..3e9d957ed3 100644
--- a/activerecord/test/cases/migration/change_table_test.rb
+++ b/activerecord/test/cases/migration/change_table_test.rb
@@ -72,6 +72,20 @@ module ActiveRecord
         end
       end
 
+      def test_references_column_type_with_polymorphic_and_type
+        with_change_table do |t|
+          @connection.expect :add_reference, nil, [:delete_me, :taggable, polymorphic: true, type: :string]
+          t.references :taggable, polymorphic: true, type: :string
+        end
+      end
+
+      def test_remove_references_column_type_with_polymorphic_and_type
+        with_change_table do |t|
+          @connection.expect :remove_reference, nil, [:delete_me, :taggable, polymorphic: true, type: :string]
+          t.remove_references :taggable, polymorphic: true, type: :string
+        end
+      end
+
       def test_timestamps_creates_updated_at_and_created_at
         with_change_table do |t|
           @connection.expect :add_timestamps, nil, [:delete_me]
diff --git a/activerecord/test/cases/migration/references_statements_test.rb b/activerecord/test/cases/migration/references_statements_test.rb
index e9545f2cce..b8b4fa1135 100644
--- a/activerecord/test/cases/migration/references_statements_test.rb
+++ b/activerecord/test/cases/migration/references_statements_test.rb
@@ -55,6 +55,11 @@ module ActiveRecord
         assert index_exists?(table_name, :tag_id, name: 'index_taggings_on_tag_id')
       end
 
+      def test_creates_reference_id_with_specified_type
+        add_reference table_name, :user, type: :string
+        assert column_exists?(table_name, :user_id, :string)
+      end
+
       def test_deletes_reference_id_column
         remove_reference table_name, :supplier
         assert_not column_exists?(table_name, :supplier_id, :integer)