How Tests are Run in Postman
The Sandbox documentation lists which commonly used libraries have been included in the environment, along with information on how to access global/environment variables, cookies, and request/response data.
Tests are constructed by defining properties on the
tests object within the environment. The name of the property will be the name of the test, and the value of the property will need to be defined as a boolean, which signals whether or not the test has passed.