assert

Drops event and emits a warning if the invariant is violated.

assert invariant:bool

Description

The assert operator asserts that invariant is true for events. In case an event does not satisfy the invariant, it is dropped and a warning is emitted. The only difference between assert and where is that latter does not emit such a warning.

Examples

Make sure that all events satisfy x > 2:

from [{x: 1}, {x: 2}, {x: 1}]
assert x > 2
―――――――――――――――――――――――――――――
{x: 1}
// warning: assertion failure
{x: 1}

Check that the topic only contains OCSF network activity events:

subscribe "network"
assert meta.name == "ocsf.network_activity"
// continue processing