locust/examples/response_validations.py

74 lines
2.6 KiB
Python

"""
This shows some useful ways to validate responses and how to exit tasks early on failure.
"""
from locust import FastHttpUser, events, run_single_user, task
from locust.exception import RescheduleTask
class BadUser(FastHttpUser):
@task
def t(self):
self.client.request("POST", "/authenticate", json={"username": "foo", "password": "bar"})
# ...
self.client.request("POST", "/checkout/confirm", json={"foo": "bar"})
# This User will behave identically to BadUser long as things go well,
# but give earlier and more detailed information if things go wrong:
class GoodUser(FastHttpUser):
@task
def t(self):
with self.rest("POST", "/authenticate", json={"username": "foo", "password": "bar"}) as resp:
# check if there was an error field in the response:
if error := resp.js.get("error"):
resp.failure(error)
# to be even more sure things went well, lets validate a success criteria:
elif message := resp.js.get("message"):
if message != "Welcome foo!":
resp.failure(f"Wrong welcome message: {message}")
# ...
# If you have long flows and can't be bothered to add validations
# for each step then at least do it for the final step:
with self.rest("POST", "/checkout/confirm", json={"foo": "bar"}) as resp:
if not resp.js.get("orderId"):
resp.failure("orderId missing")
# Break tasks early if there is a failed request
@events.init.add_listener
def register_request_listener(environment, **kwargs):
@events.request.add_listener
def request(exception, **kwargs):
if exception:
raise RescheduleTask()
# We'll now add endpoints to Locust's own WebUI to use as a target for the test.
# This means so you can't use headless or run_single_user, unless you also start a "headful" Locust instance.
#
# It is not very relevant to what this example is explaining, so feel free to ignore it.
FastHttpUser.host = "http://127.0.0.1:8089"
from flask import request
@events.init.add_listener
def locust_init(environment, **kwargs):
if environment.web_ui:
@environment.web_ui.app.route("/authenticate", methods=["POST"])
def authenticate():
username = request.get_json()["username"]
return {"message": f"Welcome {username}!"}
@environment.web_ui.app.route("/checkout/confirm", methods=["POST"])
def checkout_confirm():
foo = request.get_json()["foo"]
return {"orderId": 42}
if __name__ == "__main__":
run_single_user(GoodUser)