Python3 mock response object - python

I have one function where I am calling API to post get the resource. Since my function does not return anything then its tough to write unit test for failure scenario. Here I want to force request.get() to return different HTTP status code.
Is there anyway to mock my function to return desired status code?
foo.py
def getData():
response = requests.get(run_task_status_url, headers=iics_job_header)
logging.debug(f"Activity Monitor API response: {response.json()}")
if 200 == response.status_code:
print("success")
else 401 == response.status_code:
print("401")

Related

Locust: No statistics shown

I'm new to Locust, and I am attempting to log statistics for a POST request, and I'm using the following code along with a generic call to locust.
import json
from locust import HttpUser, task, between
import cfg
class BasicUser(HttpUser):
wait_time = between(1, 3)
v1_data = json.load(open("v1_sample_data.json", "r"))
#task
def get_v1_prediction(self):
route = "/" + cfg.lookup("model.v1.route")
response = self.client.post(
route,
json=self.v1_data,
catch_response=True,
name="API Call"
)
print(response.text)
When I start an experiment, the host is called successfully, and response.text has the expected value and is printed to the console repeatedly. However, the statistics aren't logged.
When I use a GET request in place of the POST without passing data, statistics are logged (though it's only failures because the web app only allows POST requests). Any idea what's going on here?
The catch_response=True is the culprit.
From the documentation:
catch_response – (optional) Boolean argument that, if set, can be used to make a request return a context manager to work as argument to a with statement. This will allow the request to be marked as a fail based on the content of the response, even if the response code is ok (2xx). The opposite also works, one can use catch_response to catch a request and then mark it as successful even if the response code was not (i.e 500 or 404).

Unit testing for python function-using post requests and get requests

I am trying to test the below function using unit test mocks but i am not able to do it since the return type from request get/post is of type <class 'requests.models.Response'>. please let me know how to mock this and unit test this below function:
def response_check(base_url, headers, schedule_name, response):
"""
Function to get response from dataform API and check the job status
"""
run_url = base_url + "/" + response.json()["id"]
query_response = requests.get(run_url, headers=headers)
while query_response.json()["status"] == "RUNNING":
time.sleep(10)
print("Dataform job running")
query_response = requests.get(run_url, headers=headers)
if query_response.json()["status"] in ["FAILED", "CANCELLED", "TIMED_OUT"]:
raise AirflowException(
f'Dataform task {schedule_name} has been {response.json()["status"]} for reason {response.json()["runLogUrl"]}'
)
print(query_response.json())
return "Dataform job finished"
I need to check for different response status but i am not able to mock the return type of it
Please test using http module and the http codes.
For e.g. success is http.HTTPStatus.OK
Not found is http.HTTPStatus.NOT_FOUND
Bad input is http.HTTPStatus.BAD_REQUEST etc.

Make flask return status-code that is not just a number for Vertex AI

In the Vertex AI docs it is stated "...request within 10 seconds with status code 200 OK. The contents of the response body do not matter;".
I have never used Flask before (I have used Django) but a lot of exampels on how to make a custom container is with flask. I struggle to figure out how I can return 200 OK as status code (I find that phrasing odd, since I have never seen status-codes being anything else than a number)
I have tried this
from flask import Flask,Response,make_response
.
.
#app.route('/health',methods=["GET","POST"])
def health():
return Response("OK",status=200)
#app.route('/health',methods=["GET","POST"])
def health():
return Response(status="200 OK")
#app.route('/health',methods=["GET","POST"])
def health():
return make_response("200 OK")
but neither seem to work.
Flask docs on response object mention that you have either status or status_code available.
property status: str
The HTTP status code as a string.
property status_code: int
The HTTP status code as a number.
This would imply that you could just use status_code in your example.
Alternatively you could use a return without the response object, like so:
result = {'a': 'b'}
return result, 200
As taken from this SO question semi related to yours.

Flask Middleware with both Request and Response

I want to create a middleware function in Flask that logs details from the request and the response. The middleware should run after the Response is created, but before it is sent back. I want to log:
The request's HTTP method (GET, POST, or PUT)
The request endpoint
The response HTTP status code, including 500 responses. So, if an exception is raised in the view function, I want to record the resulting 500 Response before the Flask internals send it off.
Some options I've found (that don't quite work for me):
The before_request and after_request decorators. If I could access the request data in after_request, my problems still won't be solved, because according to the documentation
If a function raises an exception, any remaining after_request functions will not be called.
Deferred Request Callbacks - there is an after_this_request decorator described on this page, which decorates an arbitrary function (defined inside the current view function) and registers it to run after the current request. Since the arbitrary function can have info from both the request and response in it, it partially solves my problem. The catch is that I would have to add such a decorated function to every view function; a situation I would very much like to avoid.
#app.route('/')
def index():
#after_this_request
def add_header(response):
response.headers['X-Foo'] = 'Parachute'
return response
return 'Hello World!'
Any suggestions?
My first answer is very hacky. There's actually a much better way to achieve the same result by making use of the g object in Flask. It is useful for storing information globally during a single request. From the documentation:
The g name stands for “global”, but that is referring to the data being global within a context. The data on g is lost after the context ends, and it is not an appropriate place to store data between requests. Use the session or a database to store data across requests.
This is how you would use it:
#app.before_request
def gather_request_data():
g.method = request.method
g.url = request.url
#app.after_request
def log_details(response: Response):
g.status = response.status
logger.info(f'method: {g.method}\n url: {g.url}\n status: {g.status}')
return response
Gather whatever request information you want in the function decorated with #app.before_request and store it in the g object.
Access whatever you want from the response in the function decorated with #app.after_request. You can still refer to the information you stored in the g object from step 1. Note that you'll have to return the response at the end of this function.
you can use flask-http-middleware for it link
from flask import Flask
from flask_http_middleware import MiddlewareManager, BaseHTTPMiddleware
app = Flask(__name__)
class MetricsMiddleware(BaseHTTPMiddleware):
def __init__(self):
super().__init__()
def dispatch(self, request, call_next):
url = request.url
response = call_next(request)
response.headers.add("x-url", url)
return response
app.wsgi_app = MiddlewareManager(app)
app.wsgi_app.add_middleware(MetricsMiddleware)
#app.get("/health")
def health():
return {"message":"I'm healthy"}
if __name__ == "__main__":
app.run()
Every time you make request, it will pass the middleware
Okay, so the answer was staring me in the face the whole time, on the page on Deferred Request Callbacks.
The trick is to register a function to run after the current request using after_this_request from inside the before_request callback. This is the code snippet of what worked for me:
#app.before_request
def log_details():
method = request.method
url = request.url
#after_this_request
def log_details_callback(response: Response):
logger.info(f'method: {method}\n url: {url}\n status: {response.status}')
These are the steps:
Get the required details from the response in the before_request callback and store them in some variables.
Then access what you want of the response in the function you decorate with after_this_request, along with the variables you stored the request details in earlier.

how to get access to error message from abort command when using custom error handler

Using a python flask server, I want to be able to throw an http error response with the abort command and use a custom response string and a custom message in the body
#app.errorhandler(400)
def custom400(error):
response = jsonify({'message': error.message})
response.status_code = 404
response.status = 'error.Bad Request'
return response
abort(400,'{"message":"custom error message to appear in body"}')
But the error.message variable comes up as an empty string. I can't seem to find documentation on how to get access to the second variable of the abort function with a custom error handler
If you look at flask/__init__.py you will see that abort is actually imported from werkzeug.exceptions. Looking at the Aborter class, we can see that when called with a numeric code, the particular HTTPException subclass is looked up and called with all of the arguments provided to the Aborter instance. Looking at HTTPException, paying particular attention to lines 85-89 we can see that the second argument passed to HTTPException.__init__ is stored in the description property, as #dirn pointed out.
You can either access the message from the description property:
#app.errorhandler(400)
def custom400(error):
response = jsonify({'message': error.description['message']})
# etc.
abort(400, {'message': 'custom error message to appear in body'})
or just pass the description in by itself:
#app.errorhandler(400)
def custom400(error):
response = jsonify({'message': error.description})
# etc.
abort(400, 'custom error message to appear in body')
People rely on abort() too much. The truth is that there are much better ways to handle errors.
For example, you can write this helper function:
def bad_request(message):
response = jsonify({'message': message})
response.status_code = 400
return response
Then from your view function you can return an error with:
#app.route('/')
def index():
if error_condition:
return bad_request('message that appears in body')
If the error occurs deeper in your call stack in a place where returning a response isn't possible then you can use a custom exception. For example:
class BadRequestError(ValueError):
pass
#app.errorhandler(BadRequestError)
def bad_request_handler(error):
return bad_request(str(error))
Then in the function that needs to issue the error you just raise the exception:
def some_function():
if error_condition:
raise BadRequestError('message that appears in the body')
I hope this helps.
I simply do it like this:
abort(400, description="Required parameter is missing")
flask.abort also accepts flask.Response
abort(make_response(jsonify(message="Error message"), 400))

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