def METHOD_NAME(source, config, client):
    catalog = source.discover(logger=logger, config=config)
    catalog = AirbyteMessage(type=Type.CATALOG, catalog=catalog).dict(exclude_unset=True)
    schemas = [stream["json_schema"] for stream in catalog["catalog"]["streams"]]
    for schema in schemas:
        jsonschema.Draft7Validator.check_schema(schema)
    type(client).streams = PropertyMock(side_effect=Exception)
    with pytest.raises(Exception):
        source.discover(logger=logger, config=config)