fbb2a41246
If we have the filter expression "WHERE m[?] = 2", the existing code simply assumed that the subscript is an object of the right type. However, while it should indeed be the right type (we already have code that verifies that), there are two more options: It can also be a NULL, or an UNSET_VALUE. Either of these cases causes the existing code to dereference a non-object as an object, leading to bizarre errors (as in issue #10361) or even crashes (as in issue #10399). Cassandra returns a invalid request error in these cases: "Unsupported unset map key for column m" or "Unsupported null map key for column m". We decided to do things differently: * For NULL, we consider m[NULL] to result in NULL - instead of an error. This behavior is more consistent with other expressions that contain null - for example NULL[2] and NULL<2 both result in NULL as well. Moreover, if in the future we allow more complex expressions, such as m[a] (where a is a column), we can find the subscript to be null for some rows and non-null for other rows - and throwing an "invalid query" in the middle of the filtering doesn't make sense. * For UNSET_VALUE, we do consider this an error like Cassandra, and use the same error message as Cassandra. However, the current implementation checks for this error only when the expression is evaluated - not before. It means that if the scan is empty before the filtering, the error will not be reported and we'll silently return an empty result set. We currently consider this ok, but we can also change this in the future by binding the expression only once (today we do it on every evaluation) and validating it once after this binding. Fixes #10361 Fixes #10399 Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Single-node functional tests for Scylla's CQL features.
These tests use the Python CQL library and the pytest frameworks. By using an actual CQL library for the tests, they can be run against any implementation of CQL - both Scylla and Cassandra. Most tests - except in rare cases - should pass on both, to ensure that Scylla is compatible with Cassandra in most features.
To run all tests against an already-running local installation of Scylla
or Cassandra on localhost, just run pytest. The "--host" and "--port"
can be used to give a different location for the running Scylla or Cassanra.
The "--ssl" option can be used to use an encrypted (TLSv1.2) connection.
More conveniently, we have two scripts - "run" and "run-cassandra" - which do all the work necessary to start Scylla or Cassandra (respectively), and run the tests on them. The Scylla or Cassandra process is run in a temporary directory which is automatically deleted when the test ends.
"run" automatically picks the most recently compiled version of Scylla in
build/*/scylla - but this choice of Scylla executable can be overridden with
the SCYLLA environment variable. "run-cassandra" defaults to running the
command cassandra from the user's path, but this can be overriden by setting
the CASSANDRA environment variable to the path of the cassandra script,
e.g., export CASSANDRA=$HOME/apache-cassandra-3.11.10/bin/cassandra.
A few of the tests also require the nodetool when running on Cassandra -
this tool is again expected to be in the user's path, or be overridden with
the NODETOOL environment variable. Nodetool is not needed to test
Scylla.
Additional options can be passed to "pytest" or to "run" / "run-cassandra" to control which tests to run:
- To run all tests in a single file, do
pytest test_table.py. - To run a single specific test, do
pytest test_table.py::test_create_table_unsupported_names. - To run the same test or tests 100 times, add the
--count=100option. This is faster than runningrun100 times, because Scylla is only run once, and also counts for you how many of the runs failed. Forpytestto support the--countoption, you need to install a pytest extension:pip install pytest-repeat
Additional useful pytest options, especially useful for debugging tests:
- -v: show the names of each individual test running instead of just dots.
- -s: show the full output of running tests (by default, pytest captures the test's output and only displays it if a test fails)