Fix migration ordering for bin/rails db:prepare across databases

activerecord/lib/active_record/railties/databases.rake

@@ -92,7 +92,7 @@ db_namespace = namespace :db do
  if db_configs.size == 1 && db_configs.first.primary?
  ActiveRecord::Tasks::DatabaseTasks.migrate
  else
- mapped_versions = ActiveRecord::Tasks::DatabaseTasks.db_configs_with_versions(db_configs)
+ mapped_versions = ActiveRecord::Tasks::DatabaseTasks.db_configs_with_versions
 
  mapped_versions.sort.each do |version, db_configs|
  db_configs.each do |db_config|

activerecord/lib/active_record/tasks/database_tasks.rb

@@ -192,9 +192,17 @@ def prepare_all
 
  seed = true
  end
+ end
+ end
 
- migrate
- dump_schema(db_config) if ActiveRecord.dump_schema_after_migration
+ each_current_environment(env) do |environment|
+ db_configs_with_versions(environment).sort.each do |version, db_configs|
+ db_configs.each do |db_config|
+ with_temporary_pool(db_config) do
+ migrate(version)
+ dump_schema(db_config) if ActiveRecord.dump_schema_after_migration
+ end
+ end
  end
  end
 
@@ -255,10 +263,10 @@ def migrate(version = nil)
  Migration.verbose = verbose_was
  end
 
- def db_configs_with_versions(db_configs) # :nodoc:
+ def db_configs_with_versions(environment = env) # :nodoc:
  db_configs_with_versions = Hash.new { |h, k| h[k] = [] }
 
- with_temporary_connection_for_each do |conn|
+ with_temporary_connection_for_each(env: environment) do |conn|
  db_config = conn.pool.db_config
  versions_to_run = conn.migration_context.pending_migration_versions
  target_version = ActiveRecord::Tasks::DatabaseTasks.target_version
@@ -552,10 +560,7 @@ def class_for_adapter(adapter)
  end
 
  def each_current_configuration(environment, name = nil)
- environments = [environment]
- environments << "test" if environment == "development" && !ENV["SKIP_TEST_DATABASE"] && !ENV["DATABASE_URL"]
-
- environments.each do |env|
+ each_current_environment(environment) do |env|
  configs_for(env_name: env).each do |db_config|
  next if name && name != db_config.name
 
@@ -564,6 +569,12 @@ def each_current_configuration(environment, name = nil)
  end
  end
 
+ def each_current_environment(environment, &block)
+ environments = [environment]
+ environments << "test" if environment == "development" && !ENV["SKIP_TEST_DATABASE"] && !ENV["DATABASE_URL"]
+ environments.each(&block)
+ end
+
  def each_local_configuration
  configs_for.each do |db_config|
  next unless db_config.database

railties/test/application/rake/multi_dbs_test.rb

@@ -565,6 +565,35 @@ class ThreeMigration < ActiveRecord::Migration::Current
  end
  end
 
+ test "db:prepare respects timestamp ordering across databases" do
+ require "#{app_path}/config/environment"
+ app_file "db/migrate/01_one_migration.rb", <<-MIGRATION
+ class OneMigration < ActiveRecord::Migration::Current
+ end
+ MIGRATION
+
+ app_file "db/animals_migrate/02_two_migration.rb", <<-MIGRATION
+ class TwoMigration < ActiveRecord::Migration::Current
+ end
+ MIGRATION
+
+ app_file "db/animals_migrate/04_four_migration.rb", <<-MIGRATION
+ class FourMigration < ActiveRecord::Migration::Current
+ end
+ MIGRATION
+
+ app_file "db/migrate/03_three_migration.rb", <<-MIGRATION
+ class ThreeMigration < ActiveRecord::Migration::Current
+ end
+ MIGRATION
+
+ Dir.chdir(app_path) do
+ output = rails "db:prepare"
+ entries = output.scan(/^== (\d+).+migrated/).map(&:first).map(&:to_i)
+ assert_equal [1, 2, 3, 4] * 2, entries # twice because for test env too
+ end
+ end
+
  test "migrations in different directories can have the same timestamp" do
  require "#{app_path}/config/environment"
  app_file "db/migrate/01_one_migration.rb", <<-MIGRATION