Take care of existing users when upgrading Clearance

When upgrading Clearance, pay attention whether the password hashing strategy might have changed. Old clearance versions (< 1.0) used SHA1-encrypted passwords by default. Current versions default to BCrypt.

If you simply upgrade without taking this into account, users will get a BCrypt::Errors::InvalidHash when trying to sign in. Your tests will not notice this, since they create new users for each scenario.

To fix it, you'll either have to force all users to reset their passwords, or you can allow old users to keep signing in with their legacy credentials. This works by

• adding the gem clearance-deprecated_password_strategies to your Gemfile

• updating config/initializers/clearance.rb:

  Copyconfig.password_strategy = Clearance::PasswordStrategies::BCryptMigrationFromSHA1