Support custom snapshot serializers on diff inputs

[motiz88]

My exact use case for this involves migrating from react-test-renderer to enzyme.mount - the former is natively supported by pretty-format while the latter ships with a custom serializer.

Would it make sense for snapshot-diff to support an API similar to expect.addSnapshotSerializer? Maybe with a slightly more hygienic twist:

import snapshotDiff from "snapshotDiff";
import enzymeToJson from "enzyme-to-json/serializer";

const diff = snapshotDiff.withSerializers([enzymeToJson]);
diff(a, b); // Runs `a` and `b` through the given serializers before diffing

I'm happy to put together a PR for this over the next few days.

[thymikee]

Happy to review, seems like a handy feature. Serializers are just pretty-format plugins, so hopefully this will be pretty straight-forward to implement.

@SimenB @pedrottimark are you ok with the API proposal? I thought about snapshotDiff.[use/add]Plugins([...]) or snapshotDiff.[use/add]Serializers([...]). But I like .withSerializers() too

[SimenB]

Yeah, that sounds good!

[siebigteroth]

Any updates on this? :-)