Added preliminary support for an agile database migration technique (currently only for MySQL)

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@818 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/test/aaa_create_tables_test.rb

@@ -45,13 +45,13 @@ class CreateTablesTest < Test::Unit::TestCase
 
   def test_table_creation
     adapter_name = ActiveRecord::Base.connection.adapter_name.downcase
-    run_sql_file ActiveRecord::Base.connection, "test/fixtures/db_definitions/" + adapter_name + ".drop.sql"
-    run_sql_file ActiveRecord::Base.connection, "test/fixtures/db_definitions/" + adapter_name + ".sql"
+    run_sql_file ActiveRecord::Base.connection, "#{File.dirname(__FILE__)}/fixtures/db_definitions/" + adapter_name + ".drop.sql"
+    run_sql_file ActiveRecord::Base.connection, "#{File.dirname(__FILE__)}/fixtures/db_definitions/" + adapter_name + ".sql"
 
     # Now do the same thing with the connection used by multiple_db_test.rb
     adapter_name = Course.retrieve_connection.adapter_name.downcase
-    run_sql_file Course.retrieve_connection, "test/fixtures/db_definitions/" + adapter_name + "2.drop.sql"
-    run_sql_file Course.retrieve_connection, "test/fixtures/db_definitions/" + adapter_name + "2.sql"
+    run_sql_file Course.retrieve_connection, "#{File.dirname(__FILE__)}/fixtures/db_definitions/" + adapter_name + "2.drop.sql"
+    run_sql_file Course.retrieve_connection, "#{File.dirname(__FILE__)}/fixtures/db_definitions/" + adapter_name + "2.sql"
     
     assert_equal 1,1
   end

activerecord/test/fixtures/migrations/1_people_have_last_names.rb

@@ -0,0 +1,9 @@
+class PeopleHaveLastNames < ActiveRecord::Migration
+  def self.up
+    add_column "people", "last_name", :string
+  end
+  
+  def self.down
+    remove_column "people", "last_name"
+  end
+end

activerecord/test/fixtures/migrations/2_we_need_reminders.rb

@@ -0,0 +1,12 @@
+class WeNeedReminders < ActiveRecord::Migration
+  def self.up
+    create_table("reminders") do |t|
+      t.column :content, :text
+      t.column :remind_at, :datetime
+    end
+  end
+  
+  def self.down
+    drop_table "reminders"
+  end
+end

activerecord/test/migration_mysql.rb

@@ -0,0 +1,104 @@
+require 'abstract_unit'
+require 'fixtures/person'
+require File.dirname(__FILE__) + '/fixtures/migrations/1_people_have_last_names'
+require File.dirname(__FILE__) + '/fixtures/migrations/2_we_need_reminders'
+
+class Reminder < ActiveRecord::Base; end
+
+class MigrationTest < Test::Unit::TestCase
+  def setup
+  end
+
+  def teardown
+    ActiveRecord::Base.connection.initialize_schema_information
+    ActiveRecord::Base.connection.update "UPDATE schema_info SET version = 0"
+
+    Reminder.connection.drop_table("reminders") rescue nil
+    Reminder.reset_column_information
+
+    Person.connection.remove_column("people", "last_name") rescue nil
+    Person.reset_column_information
+  end
+
+  def test_add_remove_single_field
+    assert !Person.column_methods_hash.include?(:last_name)
+
+    PeopleHaveLastNames.up
+
+    Person.reset_column_information
+    assert Person.column_methods_hash.include?(:last_name)
+    
+    PeopleHaveLastNames.down
+
+    Person.reset_column_information
+    assert !Person.column_methods_hash.include?(:last_name)
+  end
+
+  def test_add_table
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+    
+    WeNeedReminders.up
+    
+    assert Reminder.create("content" => "hello world", "remind_at" => Time.now)
+    assert "hello world", Reminder.find_first
+    
+    WeNeedReminders.down
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.find_first }
+  end
+
+  def test_migrator
+    assert !Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+
+    ActiveRecord::Migrator.up(File.dirname(__FILE__) + '/fixtures/migrations/')
+
+    assert_equal 2, ActiveRecord::Migrator.current_version
+    Person.reset_column_information
+    assert Person.column_methods_hash.include?(:last_name)
+    assert Reminder.create("content" => "hello world", "remind_at" => Time.now)
+    assert "hello world", Reminder.find_first
+
+
+    ActiveRecord::Migrator.down(File.dirname(__FILE__) + '/fixtures/migrations/')
+
+    assert_equal 0, ActiveRecord::Migrator.current_version
+    Person.reset_column_information
+    assert !Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.find_first }
+  end
+
+  def test_migrator_one_up
+    assert !Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+
+    ActiveRecord::Migrator.up(File.dirname(__FILE__) + '/fixtures/migrations/', 1)
+
+    Person.reset_column_information
+    assert Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+
+
+    ActiveRecord::Migrator.up(File.dirname(__FILE__) + '/fixtures/migrations/', 2)
+
+    assert Reminder.create("content" => "hello world", "remind_at" => Time.now)
+    assert "hello world", Reminder.find_first
+  end
+  
+  def test_migrator_one_down
+    ActiveRecord::Migrator.up(File.dirname(__FILE__) + '/fixtures/migrations/')
+    
+    ActiveRecord::Migrator.down(File.dirname(__FILE__) + '/fixtures/migrations/', 1)
+
+    Person.reset_column_information
+    assert Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+  end
+  
+  def test_migrator_one_up_one_down
+    ActiveRecord::Migrator.up(File.dirname(__FILE__) + '/fixtures/migrations/', 1)
+    ActiveRecord::Migrator.down(File.dirname(__FILE__) + '/fixtures/migrations/', 0)
+
+    assert !Person.column_methods_hash.include?(:last_name)
+    assert_raises(ActiveRecord::StatementInvalid) { Reminder.column_methods_hash }
+  end
+end