JSON Schema

zarr_metadata.json_schema writes the rules the readers apply as JSON Schema (draft 2020-12). Use it in two ways:

• in an editor that checks a zarr.json while you write it,
• with a validator in another language.

The module has three functions:

• node_metadata_json_schema_v3(context=None) writes the schema of a whole v3 zarr.json, array or group.
• declaration_json_schema_v3(kind, *, context=None) writes the schema of one declaration read as kind.
• json_schema(typed_dict) writes the schema of any of the package's TypedDicts, as check from zarr_metadata.typed_json reads it.

The schema describes each extension point as its context reads it:

• A claimed configuration follows its definition's TypedDict, including bounds.
• A name that nothing in the context claims may have any configuration.
• The fill value must be valid for the data type the document names.

Limits

• A schema describes each member on its own. It does not describe the rules that relate members to each other. So a document the schema accepts may still have a problem.
• The reverse holds: every JSON document the readers accept, the schema also accepts.
• A schema validator reads JSON as a parser produces it, with arrays as lists. A model's to_json returns tuples, and a Python validator does not accept a tuple as an array.

import json
from zarr_metadata.json_schema import node_metadata_json_schema_v3

with open("zarr.schema.json", "w") as f:
    json.dump(node_metadata_json_schema_v3(), f, indent=2)