Running Test in Parallel with Pytest-Xdist

Index

1. Introduction

2. Initial Setup
   2.1 Clone Project
   2.2 Run Test

3. Parameterized Tests
   3.1 Implementation
   3.2 Run Tests

4. Parallel Tests
   4.1 Conventions
   4.2 Install pytest-xdist plugin
   4.3 Running parallel tests

5. Repository

6. Bibliography

1. Introduction

This tutorial is the continuation of my other tutorial called “Configuring Multiple Browsers with Selenium and Python”.
Please take a look at it before starting this one.

This tutorial is based on the “Selenium WebDriver with Python” course, administered by Andrew Knight.
He also has a blog, click the link below to follow the news:
https://automationpanda.com/.

2. Initial Setup

As previously said, since this project continues the “Configuring Multiple Browsers with Selenium and Python” tutorial, you will have to clone its repo to continue your work.

2.1 Clone Project

Before you start, check if you are cloning the right branch:
“tutorial/multiple-browsers”.

Git Repo:
https://github.com/LuizGustavoR/intro-selenium-py/tree/tutorial/multiple-browsers

After cloning it check in the VSCode if you cloned the right branch:

2.2 Run Test

To make sure the cloned project is actually working,
open the “Command Prompt” inside the project folder.

Run the command below:

pipenv run python -m pytest

You should see this message:

3. Parameterized Tests

To parametrize tests in python you need to use code below before a test function:

@pytest.mark.parametrize('phrase', ['panda', 'python', 'polar bear'])

The first argument is a string with the variable name.
The second argument is a list of values or tuples.

3.1 Implementation

Pytest will run the test function once for each entry in the list, inserting each list item into the “phrase” variable and executing the test.

File “tests/test_search.py”:

"""
These tests cover DuckDuckGo searches.
"""
 
import pytest
 
from pages.search import DuckDuckGoSearchPage
from pages.result import DuckDuckGoResultPage

@pytest.mark.parametrize('phrase', ['panda', 'python', 'polar bear'])
def test_basic_duckduckgo_search(browser, phrase):
    search_page = DuckDuckGoSearchPage(browser)
    result_page = DuckDuckGoResultPage(browser)
   
    # Given the DuckDuckGo home page is displayed
    search_page.load()
   
    # When the user searches for the phrase variable
    search_page.search(phrase)
 
    # And the search result query is the phrase variable
    assert phrase == result_page.search_input_value()
 
    # And the search result links pertain to the phrase variable
    # for title in result_page.result_link_titles():
    #     assert PHRASE.lower() in title.lower()
 
    # Then the search result title contains the phrase variable
    assert phrase in result_page.title()

3.2 Run Tests

Run the command below:

pipenv run python -m pytest

As you can see.
Web UI tests are slow.

4. Parallel Tests

To add a parallel test to pytest use the “pytest-xdist” plugin.
“pytest-xdist” can control multiple test threads in one machine and can also distribute them across multiple machines.

4.1 Conventions

• Make sure all tests are truly independent, avoid making one test dependent upon the setup or outcome of another test.
• Should be able to run by itself without any other tests.
• Should be able to run at any order.
• Avoid test collisions, it could happen when tests access a shared state, like one test changing the user password while another test tries to do a login with the previous password and fails.

4.2 Install pytest-xdist plugin

To install the “pytest-xdist” plugin open the “Command Prompt” inside the project folder:

Then run the command below:

pipenv install pytest-xdist

You should see this message:

4.3 Running parallel tests

Now run the command below:

pipenv run python -m pytest -n 3

PS: “-n” means you want to run the tests in parallel and the number “3” means the number of threads you want.

5. Repository

I created a new branch called “tutorial/parallel-tests” for this tutorial, click the link below to see it:
https://github.com/LuizGustavoR/intro-selenium-py/tree/tutorial/parallel-tests

The end.

6. Bibliography

• https://testautomationu.applitools.com/selenium-webdriver-python-tutorial/chapter7.html
• https://www.launchableinc.com/what-is-parallel-testing