• Alex Kalderimis's avatar
    Create DesignAtVersion model · e88fd1a4
    Alex Kalderimis authored
    This adds a new model entity `DesignManagement::DesignAtVersion`, which
    wraps a design and an associated version. Mechanisms are provided for
    lazy-finding and validation.
    
    These do not have mutable properties, and validate the important
    constraint that they share an issue
    
    Finding DesignManagement::DesignAtVersion objects requires querying both
    the designs and the versions tables, and is at present more expensive
    than a single fetch. It also returns an Array instead of a relation,
    since this is not a ActiveModel object. We validate invariants in find,
    this ensures we never fetch invalid objects.
    
    * Validations:
      - checking that there is both a design and a version
      - checking that the design and the version have the same issue
      - checking that both the design and the version have an issue
    
      These validations are checked during `find` and when calling
      `instantiate`
    
    * ID
    
      It is important for GraphQL and the front-end that the model has an ID
      that can be used to lookup each combination, and be used to store this
      identity on the client.
    
    * deleted? and status methods
    
      These supplement their analogues in DesignManagement::Design with an
      awareness of the current version. Thus a
      DesignManagement::DesignAtVersion as of a version in which is was
      deleted will respond to `deleted?` appropriately.
    
      Callers should be be careful to distinguish between `dav.state ==
      :current` and `!dav.deleted?` - as of a version before a design has
      been created it will respond with:
       * `#deleted? == false`
       * `#status == :not_created_yet`
      Reflecting the fact that this is not deleted because it has not been
      created yet.
    
    This requires changes to the design and version factories to be able to
    create valid objects with nil issues, a condition that is found when
    these objects are being imported.
    e88fd1a4
version_spec.rb 10.8 KB