Unit tests mocks fails on rest API requests in Python

Question

Hi I am new to unit testing and I am digging into mocks and pytest.I am trying to unit test two rest api requests where the GET request checks if an item doesn't exist in the API and if it does not create it with POST request and to create a folder, otherwise if it exists just to create a folder.

I tried to use Mocker() and I am stuck on AttributeError: Mocker when I try to mock the GET request.

This is the code I am trying to test:


   client = requests.session()
    # get item by name
    response = client.get(
        f"https://url.com/rest/item/info?name=test_item",
        auth=username, password),
    )

    if (
        response.status_code == 200
        and response.json()["status"]
        == "Item doesn't exist!"
    ):
        logging.info(f"Creating item")
        client.post(
            "https://url.com/rest/item/create?name=test_item",
            auth=username, password),
        )
        # directory creation
        dir_make = "mkdir -p test_item/temperature"
        exec_cmd(dir_make)

    elif response.status_code == 200 and response.json()["status"]=="OK":
        # directory creation
        dir_make = "mkdir -p test_item/temperature"
        exec_cmd(dir_make)

And this is the unit test that fails with AttributeError:

def test_existing_item(requests_mock, monkeypatch):
    with requests_mock.Mocker() as mock:
        mock.get("https://url.com/rest/item/info?name=test_item", text="OK")

        resp = requests.get("https://url.com/rest/item/info?name=test_item")
        assert resp.text == "OK"

EDIT: Test for item not found and POST mock. It seems like it doesn't add coverage to the else statement. How can be tested if the item exists and only the folder needs to be added in that case?

EDIT 2: Added elif statement instead of else and 2 separate tests, still the one test_existing_items() doesn't cover the elif statement...What am I doing wrong in that case?

def test_existing_item(monkeypatch):
    with requests_mock.Mocker() as mock_request:
        mock_request.get(requests_mock.ANY, text="success!")
        resp = requests.get(
            "https://url.com/rest/item/info?name=test_item",
            auth=("mock_username", "mock_password"),
        )
        if resp.status_code == 200 and resp.json()["status"] == "OK":
            dir_make = "mkdir -p test_item/temperature"
            exec_cmd(dir_make)


    encoded_auth = b64encode(b"mock_username:mock_password").decode("ascii")

    assert mock_request.last_request.headers["Authorization"] == f"Basic {encoded_auth}"


def test_post_item(monkeypatch):
    with requests_mock.Mocker() as mock_request:
        mock_request.get(requests_mock.ANY, text="success!")
        resp = requests.get(
            "https://url.com/rest/item/info?name=test_item",
            auth=("mock_username", "mock_password"),
        )

        if resp.status_code == 200 and resp.json()["status"] == "ERROR":
            mock_request.get(requests_mock.ANY, text="success!")
            requests.post(
                "https://url.com/rest/item/create?name=test_item",
                auth=("mock_username", "mock_password"),
            )

        dir_make = "mkdir -p test_item/temperature"
        exec_cmd(dir_make)


    encoded_auth = b64encode(b"mock_username:mock_password").decode("ascii")

    assert mock_request.last_request.headers["Authorization"] == f"Basic {encoded_auth}"

I am not familiar with unit testing so any help would be appreciated to unit test this code.

OctaveL OctaveL · Accepted Answer · 2020-11-23T15:35:01

import requests
import requests_mock


def test_existing_item(monkeypatch):
    with requests_mock.Mocker() as mock:
        mock.get("https://url.com/rest/item/info?name=test_item", text="OK")

        resp = requests.get("https://url.com/rest/item/info?name=test_item")
        assert resp.text == "OK"

Don't pass requests_mock as parameter and pytest should work fine.

EDIT:

As for your edit:

It seems like it doesn't add coverage to the else statement. How can be tested if the item exists and only the folder needs to be added in that case?

That would be because your if condition is always true, so it never accesses the code below the else statement. Your second question is rather unclear to me, but I believe you want to write several tests, one for your if statement and one for your else statement. As a rule of thumb, if you need conditional logic in your test, you have a problem: either everything should go as you want it to every time you run your tests, either you should abort and have the test fail, as you want your code to have the exact same behavior every time you run it - and your tests as well, by extension.

Unit tests mocks fails on rest API requests in Python

1 Answers