Finally found the answer,
database_cleaner
gem added the cleaning
method just last week and also updated the documentation for the same. BUT this change is not available in latest gem version 1.2.0 which I sourced from rubygems.org. Approach 1
works perfectly when i source the gem from github
as below:
gem 'database_cleaner', git: 'git@github.com:DatabaseCleaner/database_cleaner.git'