Add vcdm 2.0 model and context

[PatStLouis]

Needs issuanceDate validation for vcdm 1.0 (add a current timestamp if absent)
Needs hooking up with didcomm

[ff137]

Just some early review comments

[ff137]

This can maybe be made more legible with:

    def __eq__(self, o: object) -> bool:
        """Check equality."""
        if not isinstance(o, VerifiableCredential):
            return False

        return all(
            getattr(self, attr) == getattr(o, attr)
            for attr in vars(self)
        )

or, if vars(self) returns extra properties that should be ignored, then define the relevant attributes in a list:

    def __eq__(self, o: object) -> bool:
        """Check equality."""
        if not isinstance(o, VerifiableCredential):
            return False

        attributes = [
            "context", "id", "type", "issuer", "issuance_date",
            "expiration_date", "valid_from", "valid_until",
            "credential_subject", "credential_status", "proof", "extra"
        ]

        return all(
            getattr(self, attr) == getattr(o, attr)
            for attr in attributes
        )

[PatStLouis]

I'll look into it

[ff137]

There's probably more than one place that this pattern is used and can be improved. So, could perhaps change all at once in a separate PR. But I haven't checked where else it's done.
I'm just a fan of making things more readable / maintainable :-)

[ff137]

If value is None, there would be a TypeError.

Probably worth asserting that value is of expected type before calling len or [0].
(because a dev could try call with a string, and get unclear error message).

Something like:

    def __call__(self, value: List[str]) -> List[str]:
        """Validate input value."""
        if not isinstance(value, list):
            raise ValidationError("Value must be a non-empty list.")

        if not value or value[0] not in CredentialContext.FIRST_CONTEXT:
            raise ValidationError(
                f"First context must be one of {CredentialContext.FIRST_CONTEXT}"
            )

        return value

[PatStLouis]

I can implement this, however this type of validation would of been done at the datamodel version in the class invoking this validation

[ff137]

Perhaps rename to a VALID_CONTEXTS?

[PatStLouis]

yeah I agree

[ff137]

Perhaps better to have options.proof_type != Ed25519Signature2020.signature_type

[PatStLouis]

I disagree, maybe I should change the comment. We want to explicitly prevent the 2018 version, other types might be fine down the line. I mentioned 2020 because this is the only other current registered type, but the BLS2020 stuff would be okay as well.

The limitation of 2018 is because it was implicitly included in the vcdm 1.1 context, while 2020 has its own unique context url.

[ff137]

That makes sense. Soon after I commented, I thought that the best would be for there to be a list of supported signature types, and then the condition would just assert the requested type is in the list. That would allow the error message to indicate "please use one of the supported types: ", and can easily be expanded in the future

[sonarqubecloud]

Quality Gate failed

Failed conditions
62.9% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud