normalize_test.go

ParseDockerRef normalizes the image reference following the docker
convention. This is added mainly for backward compatibility. The reference
returned can only be either tagged or digested. For reference contains both tag
and digest, the function returns digested reference, e.g.

    docker.io/library/busybox:latest@sha256:7cc4b5aefd1d0cadf8d97d4350462ba51c694ebca145b08d7d41b41acc8db5aa

will be returned as

    docker.io/library/busybox@sha256:7cc4b5aefd1d0cadf8d97d4350462ba51c694ebca145b08d7d41b41acc8db5aa.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>