assert
Operator
assert — evaluate an assertion
Synopsis
assert <expr>
Description
The assert operator evaluates the Boolean expression <expr> for each
input value, yielding its input value if <expr> evaluates to true or a
structured error if it does not.
Examples
echo {a:1} | zq -z 'assert a > 0' -
=>
{a:1}
echo {a:-1} | zq -z 'assert a > 0' -
=>
error({message:"assertion failed",expr:"a > 0",on:{a:-1}})