1 files changed, 85 insertions, 0 deletions
diff --git a/spec/support/helpers/click_house_test_helpers.rb b/spec/support/helpers/click_house_test_helpers.rb
new file mode 100644
index 00000000000..24f81a3ec01
--- /dev/null
+++ b/spec/support/helpers/click_house_test_helpers.rb
@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+module ClickHouseTestHelpers
+  def migrate(target_version, migration_context)
+    quietly { migration_context.up(target_version) }
+  end
+
+  def rollback(target_version, migration_context)
+    quietly { migration_context.down(target_version) }
+  end
+
+  def table_names(database = :main, configuration = ClickHouse::Client.configuration)
+    ClickHouse::Client.select('SHOW TABLES', database, configuration).pluck('name')
+  end
+
+  def active_schema_migrations_count(database = :main, configuration = ClickHouse::Client.configuration)
+    query = <<~SQL
+      SELECT COUNT(*) AS count FROM schema_migrations FINAL WHERE active = 1
+    SQL
+
+    ClickHouse::Client.select(query, database, configuration).first['count']
+  end
+
+  def describe_table(table_name, database = :main, configuration = ClickHouse::Client.configuration)
+    ClickHouse::Client
+      .select("DESCRIBE TABLE #{table_name} FORMAT JSON", database, configuration)
+      .map(&:symbolize_keys)
+      .index_by { |h| h[:name].to_sym }
+  end
+
+  def schema_migrations(database = :main, configuration = ClickHouse::Client.configuration)
+    ClickHouse::Client
+      .select('SELECT * FROM schema_migrations FINAL ORDER BY version ASC', database, configuration)
+      .map(&:symbolize_keys)
+  end
+
+  def clear_db(configuration = ClickHouse::Client.configuration)
+    configuration.databases.each_key do |db|
+      # drop all tables
+      lookup_tables(db, configuration).each do |table|
+        ClickHouse::Client.execute("DROP TABLE IF EXISTS #{table}", db, configuration)
+      end
+
+      ClickHouse::MigrationSupport::SchemaMigration.create_table(db, configuration)
+    end
+  end
+
+  def register_database(config, database_identifier, db_config)
+    config.register_database(
+      database_identifier,
+      database: db_config[:database],
+      url: db_config[:url],
+      username: db_config[:username],
+      password: db_config[:password],
+      variables: db_config[:variables] || {}
+    )
+  end
+
+  private
+
+  def lookup_tables(db, configuration = ClickHouse::Client.configuration)
+    ClickHouse::Client.select('SHOW TABLES', db, configuration).pluck('name')
+  end
+
+  def quietly(&_block)
+    was_verbose = ClickHouse::Migration.verbose
+    ClickHouse::Migration.verbose = false
+
+    yield
+  ensure
+    ClickHouse::Migration.verbose = was_verbose
+  end
+
+  def clear_consts(fixtures_path)
+    $LOADED_FEATURES.select { |file| file.include? fixtures_path }.each do |file|
+      const = File.basename(file)
+                  .scan(ClickHouse::Migration::MIGRATION_FILENAME_REGEXP)[0][1]
+                  .camelcase
+                  .safe_constantize
+
+      Object.send(:remove_const, const.to_s) if const
+      $LOADED_FEATURES.delete(file)
+    end
+  end
+end