## Filter predicate `BranchDeleted`

_Want:_ We can allow an event for a branch having been deleted.

_Why:_ We want to constrain CI to only deleted branches, e.g., to

update a mirror.

~~~scenario

given a Radicle node, with CI configured with broker.yaml and adapter dummy.sh

given a Git repository xyzzy in the Radicle node

given file config.yaml from filter-branchdeleted.yaml

when I run cibtool --db ci-broker.db event add --repo xyzzy --ref main --commit HEAD --kind branch-deleted

when I run cibtool --db ci-broker.db event add --repo xyzzy --ref oksa --commit HEAD --kind branch-created

when I run ./env.sh cib --config config.yaml queued

when I run cibtool --db ci-broker.db run list --json

then stdout contains "main"

then stdout doesn't contain "oksa"

~~~

~~~{#filter-branchdeleted.yaml .file .json}

db: ci-broker.db

adapters:

  default:

    command: ./adapter.sh

triggers:

  - adapter: default

    filters:

      - !BranchDeleted

~~~