Implement pytest

[campb303]

Currently there is no infrastructure to test immediate or regressive changes. pytest is a popular testing suite for Python. It should be investigated for usability. The proof of concept test could be to create tests for the Queue class in the ECNQueue Module.

[benne238]

To demonstrate the functionality of Pytest, a demonstration script will be created with no connection to current scripts within the webQueue2 to demonstrate basic testing of basic data types including numbers, strings, lists, and dictionaries.

[benne238]

https://docs.pytest.org/en/stable/getting-started.html#group-multiple-tests-in-a-class
Under "Group Multiple Tests in a Class", this is sort of what we are looking for where we set a bunch of criteria for classes, but in the example its in the script that's running.

[benne238]

To run pytest, first ensure that you install pytest by running pip install pytest from the terminal.

Then cd into the directory of the python script you would like to run (use pytester.py in webqueue2/api/pytest for example output).

Run the command: pytest [filename] -v from the terminal. The v(erbose) flag will print the status if you are testing a large number of functions.

pytest will enter test each function in the pytester.py script and check each assertion to determine if the assertion is true. In pytester.py, there isn't anything complex only checking simple assertions such as assert 3==3 or "string" == "string" however this concept should be applicable to checking functions and classes that require any input.

[benne238]

Pytest: Post Test Reports

The example code in this guide demonstrates how to output information to a text file every time pytest runs. In this particular example, every time pytest runs, the name of any function that fails is output to a "failures" file in the same directory. Example output of failed functions:

test_example_pytester.py::test_num
test_example_pytester.py::test_string
test_example_pytester.py::test_array
test_example_pytester.py::test_dictionary

This guide discusses using conftest.py and basic custom hooks and plugins.

[benne238]

Pytest Post Test Reports: Current Implementation

The way pytest is configured, as of now, is to output the name of any function that failed during the execution of pytest. To determine if the most recent execution of pytest failed, without looking at the output in the terminal, simply search for the existence of the pytest_failures document within the pytest directory. The existence of the pytest_failures indicates that at least function failed during the execution of pytest (pytest_failures will report all failed functions). If pytest_failures doesn't exist, then no functions failed the last time pytest was executed.

[campb303]

Tests for Monday's demo (for the Queue class):
After initialization, Queue has attributes of:

• self.name (string)
• self.items (list[Item])
• self.jsonData (dict) w/ keys of:
  • "name" (str) = self.name
  • "length": (int) = self.items.length

[benne238]

Pytest with Queue Class

There is now a very basic pytest script within the api folder that demonstrates a very basic method of testing the Queue class for basic assertions.

import pytest
from ECNQueue import Queue, Item

testQueue = Queue("ce")

@pytest.mark.name
def test_Name():
    assert type(testQueue.name) == str
    assert testQueue.name == "ce"

@pytest.mark.Items
def test_Items():
    assert type(testQueue.items) == list
    assert len(testQueue.items) == 48

def test_Json():
    assert type(testQueue.jsonData["name"]) == str
    assert testQueue.name == testQueue.jsonData["name"]
    assert type(len(testQueue.items)) == int
    assert len(testQueue.items) == testQueue.jsonData["length"]
    assert testQueue.items[0].jsonData["number"] == "17"

This script imports the Queue and Item from ecnqueue.py script and parses the ce queue. The script then specifically tests the json output from the queue, the name of the queue and the items within that queue by making basic assertions.