Automatically maintain test database schema

* Move check from generated helper to test_help.rb, so that all
  applications can benefit
* Rather than just raising when the test schema has pending migrations,
  try to load in the schema and only raise if there are pending
  migrations afterwards
* Opt out of the check by setting
  config.active_record.maintain_test_schema = false
* Deprecate db:test:* tasks. The test helper is now fully responsible
  for maintaining the test schema, so we don't need rake tasks for this.
  This is also a speed improvement since we're no longer reloading the
  test database on every call to "rake test".

1 files changed, 11 insertions, 0 deletions

diff --git a/guides/source/4_1_release_notes.md b/guides/source/4_1_release_notes.md
index 171572c77c..0de7860f7d 100644
--- a/guides/source/4_1_release_notes.md
+++ b/guides/source/4_1_release_notes.md
@@ -281,6 +281,13 @@ for detailed changes.
 * Add `Application#message_verifier` method to return a message
   verifier. ([Pull Request](https://github.com/rails/rails/pull/12995))
 
+* The `test_help.rb` file which is required by the default generated test
+  helper will automatically keep your test database up-to-date with
+  `db/schema.rb` (or `db/structure.sql`). It raises an error if
+  reloading the schema does not resolve all pending migrations. Opt out
+  with `config.active_record.maintain_test_schema = false`. ([Pull
+  Request](https://github.com/rails/rails/pull/13528))
+
 Action Pack
 -----------
 
@@ -421,6 +428,10 @@ for detailed changes.
 * Deprecated `ConnectionAdapters::SchemaStatements#distinct`,
   as it is no longer used by internals. ([Pull Request](https://github.com/rails/rails/pull/10556))
 
+* Deprecated `rake db:test:*` tasks as the test database is now
+  automatically maintained. See railties release notes. ([Pull
+  Request](https://github.com/rails/rails/pull/13528))
+
 ### Notable changes
 
 * Added `ActiveRecord::Base.to_param` for convenient "pretty" URLs derived from