function unmarshallValue()

in packages/dynamodb-data-marshaller/src/unmarshallItem.ts [50:124]
70 lines of code
34 McCabe index (conditional complexity)

function unmarshallValue(schemaType: SchemaType, input: AttributeValue): any {
    switch (schemaType.type) {
        case 'Any':
        case 'Collection':
        case 'Hash':
            const {
                onEmpty = 'leave',
                onInvalid = 'throw',
                unwrapNumbers = false,
            } = schemaType;
            const autoMarshaller = new Marshaller({onEmpty, onInvalid, unwrapNumbers});
            return autoMarshaller.unmarshallValue(input);
        case 'Binary':
            if (input.NULL) {
                return new Uint8Array(0);
            }

            return input.B;
        case 'Boolean':
            return input.BOOL;
        case 'Custom':
            return schemaType.unmarshall(input);
        case 'Date':
            return input.N ? new Date(Number(input.N) * 1000) : undefined;
        case 'Document':
            return input.M
                ? unmarshallItem(
                    schemaType.members,
                    input.M,
                    schemaType.valueConstructor
                ) : undefined;
        case 'List':
            return input.L ? unmarshallList(schemaType, input.L) : undefined;
        case 'Map':
            return input.M ? unmarshallMap(schemaType, input.M) : undefined;
        case 'Null':
            return input.NULL ? null : undefined;
        case 'Number':
            return typeof input.N === 'string' ? Number(input.N) : undefined;
        case 'Set':
            switch (schemaType.memberType) {
                case 'Binary':
                    if (input.NULL) {
                        return new BinarySet();
                    }

                    return typeof input.BS !== 'undefined'
                        ? new BinarySet(input.BS as Array<Uint8Array>)
                        : undefined;
                case 'Number':
                    if (input.NULL) {
                        return new Set<number>();
                    }

                    return input.NS ? unmarshallNumberSet(input.NS) : undefined;
                case 'String':
                    if (input.NULL) {
                        return new Set<string>();
                    }

                    return input.SS ? unmarshallStringSet(input.SS) : undefined;
                default:
                    throw new InvalidSchemaError(
                        schemaType,
                        `Unrecognized set member type: ${schemaType.memberType}`
                    );
            }
        case 'String':
            return input.NULL ? '' : input.S;
        case 'Tuple':
            return input.L ? unmarshallTuple(schemaType, input.L) : undefined;
    }

    throw new InvalidSchemaError(schemaType, 'Unrecognized schema node');
}