def from_file()

in terranova/resources.py [0:0]
29 lines of code
8 McCabe index (conditional complexity)

    def from_file(path: Path) -> "ResourcesManifest":
        """
        Read a resources manifest

        Args:
            path: path to manifest.
        Raises:
            MissingManifestError: if the manifest is missing.
            UnreadableManifestError: if the manifest can't be read.
            VersionManifestError: if the version manifest isn't supported.
            InvalidManifestError: if the manifest isn't invalid.
        """
        if not path.exists() or not path.is_file():
            raise MissingManifestError(path)
        if not os.access(path.as_posix(), os.R_OK):
            raise UnreadableManifestError(path)

        with path.open(
            Constants.FILE_MODE_READ, encoding=Constants.ENCODING_UTF_8
        ) as file_descriptor:
            try:
                data = yaml.safe_load(file_descriptor)
            except yaml.YAMLError as err:
                raise InvalidManifestError(path) from err

            # Check version
            version = data.get("version", "1.0")

            # Get configuration schema
            try:
                schema = pkgutil.get_data(
                    __name__, f"schemas/manifest_schema_v{version}.json"
                )
                if not schema:
                    raise FileNotFoundError(
                        f"The schema `schemas/manifest_schema_v{version}.json` can't be found"
                    )
            except FileNotFoundError as err:
                raise VersionManifestError(version) from err
            schema = json.loads(schema)

            # Validate manifest
            try:
                validate(instance=data, schema=schema)
            except ValidationError as err:
                raise InvalidManifestError(path) from err
            # noinspection PyUnresolvedReferences
            return ResourcesManifest.from_dict(data)  # type: ignore[attr-defined]