The Android components project uses a similar versioning and release process as Firefox (New major version releases at fixed intervals).

Major releases

  • Major releases happen at fixed intervals (currently on Tuesday every week)
  • Every release increments the major version (e.g. 1.0.0 -> 2.0.0 -> 3.0.0)
  • Major releases are tagged on and shipped from the master branch.

Point releases

  • Point releases happen on demand whenever an app project requires a new version but cannot update to the latest release version yet or whenever a new release version is not available yet.
  • Point releases are created from a release branch, created from a previously tagged release.
  • The minor or patch version is increased depending on whether the release introduces backported functionality or just fixes bugs (e.g. 1.0.0 -> 1.1.0 or 2.0.0 -> 2.0.1).

Rationale and alternatives

Release cycle and stability

The Android components project follows a rapid release cycle to get new functionality into the hands of consuming apps as soon as possible. For this reason the project does not have a long release stability phase (e.g. 1.0.0 -> 1.0.1 -> 1.0.2 -> 1.1.0 -> 1.1.1).

App teams are encouraged to update to the latest release frequently. The Android Components team tries to minimize the amount of breaking API changes. Frequent updates minimize the amount of API changes when updating Android Components.

Versioning

All Android Components are released together using a unified version number. This makes it easy for the Android Components team to guarantee that this set of components is guaranteed and tested to work together.

The downside of a shared version is the loss of semantic versioning semantics on a per component level. It is entirely possible that a component is released using a new major version and there’s not a single code change in this component in the new release. Instead the changelog is the primary mechanism to communicate major and minor changes in a component.

At this time individually semantically versioned components would introduce a too large maintenance overhead for the Android Components team (Individual releases, release manager/owner for every component, guaranteeing compatibility across many versions).