Get started: Selenium + pytest

Automated tests using Python flavor of the Selenium framework.

• Get started: Selenium + pytest
• How to install
  • Initial setup
  • Configure dependecies
• How to execute tests
  • Expected output of test run
  • Selecting a specific browser
  • Set a default browser to run a specific test
  • Using pytest parametrize option to repeat test on different browsers
  • Using containers to run tests
    • Custom environment variables

How to install

Initial setup

First things first: This is a Python project. So you need to make sure to have Python installed.

# Verify your local python version installed:
python3 --version

The recommended version is Python 3.11.2. Follow the official docs to install it, if you need.

This project also recommends the use of virtual environment to handle the dependency isolation. Feel free to read the official documentation for more information about it.

Configure dependecies

Use the following steps to configure this project of Test Automation:

# clone this project from GitHub
git clone [email protected]:thiagojacinto/selenium-with-python-getstarted.git

# chage to your brand new local repository directory
cd selenium-with-python-getstarted

# create a Python virtual enviroment and activate it (UNIX compatible)
python3 -m venv .venv \
    && source .venv/bin/activate

# install the dependencies from the lock, that guarantee the same dependencies verisons:
pip install -r requirements-lock.txt

How to execute tests

Once configured, to execute the tests, go to the project directory then type:

pytest

# You can use pytest -vv for a more verbose test output

Expected output of test run

An output like this is expected after the tests are all run:

Selecting a specific browser

You may want to use a specific browser to run the tests, therefore use the following argument to achieve this:

pytest --use-browser firefox

The supported browser options list is described here. And with pytest -h, you can find more about this option:

Custom options:
  --use-browser=USE_BROWSER
        Define the browser to be executed. Current supported versions: chrome, firefox, safari, headless-chrome, headless-firefox, headless-safari

Set a default browser to run a specific test

You can also set a default browser to run the tests by using a custom Pytest's Mark, as the exemple below:

@pytest.mark.FORCE_BROWSER("firefox")
def test_successfully_run_with_firefox(...):
  ...

The test above will be run using the Firefox browser and this mark takes precedence over the CLI argument --use-browser, if it is passed.

Using pytest parametrize option to repeat test on different browsers

It's useful to use the powers of pytest framework to handle situations where the specific test case should be run against a variety of different browsers. A way to make it works it's by using pytest.mark.parametrize fixture, as the example below:

@pytest.mark.parametrize(
        (""), [
            pytest.param(id="default"), 
            pytest.param(id="edge", marks=pytest.mark.FORCE_BROWSER("edge")),
            pytest.param(id="chrome", marks=pytest.mark.FORCE_BROWSER("chrome"))
            ]
    )
def test_successfully_run_with_edge_chrome_and_default_config(...):
  ...

The way the example above works is by only applying:

• an ID: to be displayed on the pytest output;
• the custom FORCE_BROWSER mark: to force the use of the specified browser.

Using containers to run tests

To rapidly set a development environment, using Docker to run containers is a valid alternative. Documentation for docker-selenium is set on the project official repository and it might be a good idea to take some time to read it.

The first steps are condensed on this Makefile, and you could start with the make help command to see the basics to: put containers UP or DOWN with Docker, then execute the tests on this infrastructure. All containers configuration are disposed on compose.yaml

make help
# > These are all the avalaible commands ...

make se-docker-up # starts the docker containers set by containers/compose.yaml file

make se-docker-run-tests #Running tests for Firefox, Chrome and Edge browsers from docker containers

make se-docker-down # terminates the docker containers set by containers/compose.yaml file

Custom environment variables

The following environment variables are used to and often necessary, depending on what and how the tests should be executed:

• SELENIUM_HOST: Used to set WHERE to point out the WebDriver's API requests to, when using the --use-browser is set to remote; (introduced)
• SELENIUM_BROWSER: This one refers to what type of browser will be used on the remote test execution. Important to use on GitHub's action workflow (introduced by #2)