Namespace backup dir by activerecord version and update CONTRIBUTING.md to demonstrate loading from a template.

Author: keithdoggett

CONTRIBUTING.md

@@ -78,6 +78,26 @@ RAILS_SOURCE="path/to/local_copy" bundle exec rake test
 
 `test/config.yml` assumes CockroachDB will be running at localhost:26257 with a root user. Make changes to `test/config.yml` as needed.
 
+### Run Tests from a Backup
+
+Loading the full test schema every time a test runs can take a while, so for cases where loading the schema sequentially is unimportant, it is possible to use a backup to set up the database. This is significantly faster than the standard method and is provided to run individual tests faster, but should not be used to validate a build.
+
+First create the template database.
+
+```bash
+bundle exec rake db:create_test_template
+```
+
+This will create a template database for the current version (ex. `activerecord_test_template611` for version 6.1.1) and create a `BACKUP` in the `nodelocal://self/activerecord-crdb-adapter/#{activerecord_version}` directory.
+
+To load from the template, use the `COCKROACH_LOAD_FROM_TEMPLATE` flag.
+
+```bash
+COCKROACH_LOAD_FROM_TEMPLATE=1 TEST_FILES="test/cases/adapters/postgresql/ddl_test.rb" bundle exec rake test
+```
+
+And the `activerecord_unittest` database will use the `RESTORE` command to load the schema from the template database.
+
 # Improvements
 
 

test/support/template_creator.rb

@@ -14,12 +14,20 @@ module TemplateCreator
     host: 'localhost'
   }.freeze
 
-  BACKUP_PATH = "nodelocal://self/activerecord-crdb-adapter".freeze
+  BACKUP_DIR = "nodelocal://self/activerecord-crdb-adapter"
 
   module_function
 
+  def ar_version
+    ActiveRecord.version.version.gsub('.','')
+  end
+
+  def version_backup_path
+    BACKUP_DIR + "/#{ar_version}"
+  end
+
   def template_db_name
-    "activerecord_unittest_template#{ActiveRecord.version.version.gsub('.', '')}"
+    "activerecord_unittest_template#{ar_version}"
   end
 
   def connect(connection_hash=nil)
@@ -60,11 +68,10 @@ def create_test_template
     conn['database'] = template_db_name
     connect(conn)
 
-
     load_schema
 
     # create BACKUP to restore from
-    ActiveRecord::Base.connection.execute("BACKUP DATABASE #{template_db_name} TO '#{BACKUP_PATH}'")
+    ActiveRecord::Base.connection.execute("BACKUP DATABASE #{template_db_name} TO '#{version_backup_path}'")
   end
 
   def restore_from_template
@@ -82,6 +89,6 @@ def restore_from_template
     end
     ActiveRecord::Base.connection.execute("CREATE DATABASE activerecord_unittest")
 
-    ActiveRecord::Base.connection.execute("RESTORE #{template_db_name}.* FROM '#{BACKUP_PATH}' WITH into_db = 'activerecord_unittest'")
+    ActiveRecord::Base.connection.execute("RESTORE #{template_db_name}.* FROM '#{version_backup_path}' WITH into_db = 'activerecord_unittest'")
   end
 end