Consumer version selectors are the (new) way to configure which pacts the provider verifies. Instead of providing a list of tag names (as in the past) a list of selector objects is provided. These allow a much more flexible and powerful approach to specifying which pacts to verify.
A consumer version selector has the following properties:
tag: The name of the tag which applies to the pacticipant (application) versions of the pacts you want to verify. Common examples of the tag names used here are
latest: Whether or not to verify only the pact that belongs to the latest application version. The most common use case is to set this to true. When false, null or ommitted, the pacts that belong to all application versions with the specified tag will be verified. This is to support the scenario when an API has many production versions, and hence pacts (eg. a mobile consumer).
consumer: Filter pacts by the specified consumer. When ommitted, all consumer are included. This is generally not needed, as the most common use case is to verify pacts for all consumers. It is useful in the scenario when an API has multiple versions of one particular consumer in production (eg. a mobile consumer) as well as a single version of another consumer (eg. an API consumer). See examples below.
fallbackTag: If a pact for the specified
tagdoes not exist, then use this tag as a fallback. This is useful for co-ordinating development between consumer and provider teams when matching branch names are used.
The Pact Broker API for retriving pacts by selectors deduplicates the pacts based on their content. This means that if the same content was published in multiple selected pacts, the verification for that content will only need to run once. This is quite common when there hasn't been a change to a pact for a while, and the same pact content is present in development, test and production pacts.
Verifing the latest development, test and master pacts
This is the most common use case.
Using a fallback tag for coordinated branch development
Dynamically determine the current branch of the provider, see if there is a matching pact for that branch, fallback to the
master pact if none exists.
Verifying pacts where the consumer is a mobile application
Verify the pacts for the latest
test versions, and all
production versions of "my-mobile-consumer".
Verifying a pacts where one consumer is a mobile application
Verify the latest
production version of all consumers, and all
production versions of "my-mobile-consumer". Note that the pacts are deduplicated, so despite being included by 2 selectors, the verification of the latest production pact for "my-mobile-consumer" will only run once.
Verifying the overall latest pact for each consumer
This is syntatically possible, but not recommended, as pacts for different branches of the consumer may overwrite each other as the current latest.