Branching

  • Never put feature branches in the remote/origin/trunk.
  • Control access to new features with runtime configuration, not branching.

Feature Branches

Traditional: Create a branch for this feature in the remote, develop the feature on the branch over some period of time, then merge the entire branch back into master when complete.

Drawbacks:

  • You have to merge. Merging can be painful and error prone.
  • This aggregates risk into a single high-risk merge event at the end of development: both explicitly (everything is merged at once) and subtly (commits on the branch aren’t immediately available/so easier to hold them to a lower bar of quality).
  • When you have multiple feature branches, it’s impossible to test interactions between the features.
  • You generally can’t A/B test code in feature branches, can’t roll it out to a small percentage of uses, and can’t easily turn it on for just employees since it is in a separate branch.

Advantages:

  • Before the merge, no impact on production.

Advantages of not Feature Branching:

  • You don’t have to do merges.
  • Risk is spread out more evenly into a large number of small risks.
  • You can test interactions between features in development easily.
  • You can A/B test and do controlled rollouts easily.

Controlling Access to Features

Build a runtime configuration which defines which features are visible, based on the tier (dev, testing, prod), the logged in user, global config, A/B test groups, whatever else. It should look like this:

if (is_feature_launched('poke')) {
  show_poke()
}

Links

Recommendations on Branching