WebHost: validate uploaded datapackage and calculate own checksum

[Berserker66]

What is this fixing or adding?

validate uploaded datapackage and calculate own checksum

How was this tested?

Turned the actual ID of "Donald Lucky Lucky" into None. Then got:

schema.SchemaError: Key 'item_name_to_id' error:
Key 'Donald Lucky Lucky' error:
None should be instance of 'int'

If this makes graphical changes, please attach screenshots.

[black-sliver]

• did you look into validating via TypedDict instead of Schema? (we have a TypedDict in worlds/__init__.py. I read up on that and the frameworks that support(ed) that were massive, so I gave up on that idea, but I may have missed something)
• should we maybe move the Schema to worlds/__init__.py so it's local to the TypedDict?

[Berserker66]

I considered that we already have a typed dict, but also am not a aware of a small and quick way of validating it. But we do already have schema, so I went with that.

Second, maybe, I considered that too, I ended up moving it to webhost to keep init time low as we avoid a schema import if we don't need it. But I also didn't measure how long the module needs, so this may be over-engineered.

[black-sliver]

Should maybe add a code path to actually display the Exception.
I get

Internal Server Error

The server encountered an unexpected internal server error

(generated by waitress)

But validation itself seems to work, so approving for now.

[Berserker66]

there's multiple things that lead to a generic "internal server error" especially on that page. I agree that we should improve that at some point.