Description

Pickling of instances from Artifact.from_type(...) classes fails because the class name is not actually available in arti.artifacts. This fixes that by using a _DynamicArtifact intermediate class with a custom __reduce__ implementation that triggers the dynamic class to be regenerated and then an object instantiated.

While we could simply add the generated types to globals() after generation, that wouldn't handle:

• loading a pickled representation from a separate session if that specific dynamic class hadn't already been generated in this session
• classes with duplicate names (they're currently named based on the Type.__name__, but there might be multiple, different instance of the same type)

I think there are some larger changes we can make to Artifact/Producer that will remove the need for these dynamic classes (and thus these hacks), but this will suffice for now.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Tests have been added for simple pickle.{dumps,loads} in the same session, but I tested reloading a pickle file across sessions by hand (this is harder to reliably test for).

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in upstream modules