fix: relax JSON normalizer type validation

[rooperuu]

Description

Support various operations that previously only worked on the dlt.common.normalizers.json.relational normalizer. This includes dlt.common.normalizers.json.relational_no_coercion or any derived custom normalizers such as:

from dlt.common.normalizers.json import relational

class DataItemNormalizer(relational.DataItemNormalizer):
    pass

This also fixes max_nesting configuration on these normalizer subtypes.

import os
import dlt

os.environ["SCHEMA__JSON_NORMALIZER"] = (
    '{"module": "dlt.common.normalizers.json.relational_no_coercion", "config": {"max_nesting": 3}}'
)

@dlt.source
def nothing():
    yield from []

source = nothing()
print(source.max_table_nesting)  # 3

Related Issues

• Fixes Data item normalizer type validation is overly strict #3892

[Travior]

@rooperuu thanks a lot for posting your fix. There's a couple of things I would want to do differently when incorporating this into dlt. I forgot to ask: Are you willing (and have time 😁) to work on this then I can give you a proper review, otherwise I can take this over

[rooperuu]

@Travior Thanks for taking a look!

I think we need this for our use case, so I can spend some time on this, or whichever is easiest. Let me know what you would like to change and I can do changes accordingly.