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Last updated: 2 Nov 2023

whitehall: Feature Flags

Feature flags in Whitehall are managed using the FlipFlop gem. The gem is currently configured so that only the ActiveRecord and default strategies are active.

Toggling Feature Flags

In local development environments, a UI is available to make it easy to toggle feature flags on and off during development. The UI can be accessed at http://whitehall-admin.dev.gov.uk/flipflop. To toggle feature flags in non-local environments, the rake task provided by FlipFlop can be used, e.g.

bundle exec rake flipflop:turn_on[new_feature,active_record]   # Enables the new feature with the Active Record strategy
bundle exec rake flipflop:turn_off[new_feature,active_record]  # Disables the new feature with the Active Record strategy

Testing with Feature Flags

Feature flags are made accessible via the [feature_flags] helper on ActionController::TestCase.

To toggle a feature flag in your controller test:

feature_flags.switch! :your_feature, true