Predicates

A predicate is a condition expression that evaluates a part of a response against an expectation. The result of a predicate is either true or false.

Syntax

A predicate will always appear between a query and a value (such as an assert’s expectation). Here is a table of all supported predicates and their functions.

Predicate	Description	Example
==	Query and value are equal.	status == 200
!=	Query and value are not equal.	status != 200
<	Query is less than value.	duration < 2000
<=	Query is less than or equal to value.	duration <= 2000
>	Query is greater than value.	header Content-Length > 0
>=	Query is greater than or equal to value.	jsonpath $.age >= 18
contains	Query contains value as a string.	body contains Hello, World!
startswith	Query begins with value as a string.	body startswith Hello
endswith	Query ends with value as a string.	body endswith World!
matches	Query matches value as a regular expression	body matches ^Hello.+$
in	Query matches one of a set of values	status in [ 200, 201 ]

Negation

Any predicate can be negated to achieve the opposite effect by using the not keyword. For example:

status not in [ 400, 500 ] # will succeed as long as the status is NOT 400 or 500