Module gamslib.sip.validation.sip_json

Validation functions for the sip.json file in GAMS Bagit directories.

This module provides functions to validate the sip.json file in a GAMS packaging context, ensuring that it is present, valid, and conforms to its declared JSON schema.

Features

• Checks for existence and validity of sip.json.
• Validates JSON structure and schema compliance.
• Ensures the mainResource is listed in contentFiles.
• Raises BagValidationError for any validation failures.

Usage

Call validate_sip_json()(bag_dir) to validate the sip.json file in a Bagit directory.

Functions

def validate_main_resource(data: dict) ‑> None

Expand source code

def validate_main_resource(data: dict) -> None:
    """
    Ensure the object main resource id is listed in the contentFiles.

    Args:
        data (dict): Parsed JSON data from sip.json.

    Raises:
        BagValidationError: If the mainResource is not listed in contentFiles.
    """
    mainresource = data.get("mainResource", "")
    known_ds_ids = [content_file["dsid"] for content_file in data["contentFiles"]]
    if mainresource and mainresource not in known_ds_ids:
        raise BagValidationError(
            f"mainResource '{data['mainResource']}' is not listed in contentFiles"
        )

Ensure the object main resource id is listed in the contentFiles.

Args

data : dict

Parsed JSON data from sip.json.

Raises

BagValidationError

If the mainResource is not listed in contentFiles.

def validate_sip_json(bag_dir: pathlib._local.Path) ‑> None

Expand source code

def validate_sip_json(bag_dir: Path) -> None:
    """
    Validate the sip.json file in a Bagit directory.

    Args:
        bag_dir (Path): Path to the Bagit directory.

    Raises:
        BagValidationError: If the sip.json file is missing, contains invalid JSON,
            is missing a $schema, fails schema validation, or has an invalid mainResource.

    Notes:
        - Checks for the existence of sip.json in data/meta.
        - Validates the JSON structure and schema compliance.
        - Ensures the mainResource is listed in contentFiles.
    """
    sip_json_file = bag_dir / "data" / "meta" / "sip.json"
    if not sip_json_file.is_file():
        raise BagValidationError(f"{bag_dir}: sip.json file does not exist")
    try:
        data = json.load(sip_json_file.open(encoding="utf-8", newline=""))
    except json.JSONDecodeError as e:
        raise BagValidationError(f"Invalid JSON in sip.json: {e}") from e

    if "$schema" not in data:
        raise BagValidationError(f"{bag_dir}: Missing '$schema' in sip.json")

    schema = utils.fetch_json_schema(data["$schema"])

    # do the real validation
    try:
        jsonschema.validate(data, schema)
        validate_main_resource(data)
    except jsonschema.ValidationError as e:
        raise BagValidationError(f"Invalid JSON in sip.json: {e}") from e
    except jsonschema.SchemaError as e:
        raise BagValidationError(
            f"{bag_dir}: The JSON Schema referenced in 'sip.json' is not valid: {e}"
        ) from e
    except referencing.exceptions.Unresolvable as e:
        raise BagValidationError(
            f"Failed to resolve a reference in the JSON Schema: {e}"
        ) from e

Validate the sip.json file in a Bagit directory.

Args

bag_dir : Path

Path to the Bagit directory.

Raises

BagValidationError

If the sip.json file is missing, contains invalid JSON, is missing a $schema, fails schema validation, or has an invalid mainResource.

Notes

• Checks for the existence of sip.json in data/meta.
• Validates the JSON structure and schema compliance.
• Ensures the mainResource is listed in contentFiles.