Selenium Testing Library

Selenium Testing Library (STL) is a Python library implementing Testing-Library in Selenium.

Dependencies

• Python 3.8, 3.9, 3.10, 3.11, 3.12, 3.13-dev
• selenium >= 3.0.0

Installation

pip install selenium-testing-library

Quick Start

from selenium import webdriver
from selenium_testing_library import Screen

driver = webdriver.Chrome()
driver.open('https://google.com/')

screen = Screen(driver)
search_input = screen.find_by_title("Search")
search.send_keys("Dogs")
search_button = screen.find_by_text("Google Search")
search_button.click()
screen.wait_for_stale(search_button)

Finding elements

STL implements the Queries API from the Testing Library. The Testing Library queries get_by, query_by, find_by, and the multiple element equivalents get_all_by, query_all_by, find_all_by are used in places where you would normally use Selenium's find_element and find_elements functions.

The difference between the different queries (get_by, query_by, find_by) is whether the query will throw an error if the element was not found (get_by), return None (query_by) or block, wait and retry until the element is found (find_by).

• get_by returns the element matched and throws an exception if zero or more than one element matches. This is the main function that we should be using to locate elements on a page.
• query_by returns the element matched or None if no element match. It throws an exception if more than one element matches. Mostly used for asserting that an element is not present: assert not screen.query_by_text("not on page").
• find_by behaves like get_by, but uses a WebDriverWait to wait until the element is present in the DOM.
• get_all_by returns a list of elements matched. It raises an exception if no elements match.
• query_all_by returns a list of elements matched. It returns an empty list when no elements match.
• find_all_by behaves like get_all_by, but uses a WebDriverWait to wait until the elements are present in the DOM.

When an element is found the queries return a Selenium WebElement or a list containing Selenium WebElements when using get_all_by, query_all_by, find_all_by.

The queries accept a tuple containing the By class identifier and the search query, so they can be used with XPath, Css or any other native Selenium selector:

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium_testing_library import Screen

screen = Screen(webdriver.Chrome())
screen.get_by((By.CSS, ".my_class")) # Will throw an exception if the element is not found
screen.query_by((By.ID, "my_id")) # you can use regular tuples as if you were using Selenium's find_element()
screen.find_by((By.XPATH, "//div"), timeout=5, poll_frequency=0.5) # locators for searching through text also work

Locator Classes

For convenience Locator classes can be used instead of the tuples:

from selenium import webdriver
from selenium_testing_library import Screen, locators

screen = Screen(webdriver.Chrome())
screen.get_by(locators.Css(".my_class")) # Will throw an exception if the element is not found
screen.query_by(locators.Id("my_id")) # you can use regular tuples as if you were using Selenium's find_element()
screen.find_by(locators.XPath("//div"), timeout=5, poll_frequency=0.5) # locators for searching through text also work

Testing Library Selectors

Besides all the Selenium native By selectors, the queries also support Testing Library's selectors:

• Role
• LabelText
• PlaceholderText
• Text
• DisplayValue
• AltText
• Title
• TestId

from selenium import webdriver
from selenium_testing_library import Screen, locators

screen = Screen(webdriver.Chrome())
screen.get_by(locators.Text("My Text"))
screen.query_by(locators.Role("button", pressed=True))
screen.find_by(locators.TestId("my-test"), timeout=5, poll_frequency=0.5) # locators for searching through text also work

Helper functions

For convenience helper functions on the screen class are available to avoid instantiating locator classes all over the place:

screen.get_by_role(role_name) Queries for elements with the given role. screen.get_by_label_text(text) Queries for label elements that match the text string and return the corresponding input element. screen.get_by_placeholder_text(text) Queries elements with the matching placeholder attribute. screen.get_by_text(text) Queries elements where the content matches the provided text. screen.get_by_display_value(value) Queries inputs, textareas, or selects with matching display value. screen.get_by_alt_text(text) Queries elements with the matching alt attribute. screen.get_by_title(text) Queries elements with the matching title attribute. screen.get_by_test_id(value) Queries elements matching the data-testid value. screen.get_by_css(css) Queries elements matching the specified css selector. screen.get_by_xpath(xpath) Queries elements matching the specified xpath selector.

There are also query_by_*, find_by_*, get_all_by_*, query_all_by_*, find_all_by_* equivalents.

Note: The selenium project has removed the find_element_by_* and find_elements_by_* helper functions in the Selenium 4.3.0 release, so I just want to state that the screen helper functions will never be deprecated or removed.

Examples:

from selenium import webdriver
from selenium_testing_library import Screen

screen = Screen(webdriver.Chrome())
screen.query_by_role("role_name")
screen.get_by_label_text("label text")
screen.find_all_by_text("my text", timeout=5, poll_frequency=0.5)
screen.get_all_by_alt_text("alt text")

Wait functions

wait_for(condition_function) Waits until the condition function returns a truthy value. wait_for_stale(element) Waits until the element is removed from the DOM.

Examples:

from selenium import webdriver
from selenium_testing_library import Screen, locators

screen = Screen(webdriver.Chrome())

# Wait for the element to be clickable:
element = screen.get_by_text("Submit")
screen.wait_for(lambda _: element.is_enabled(), timeout=5, poll_frequency=0.5)
# Wait for the element to be removed from the page:
screen.wait_for_stale(element)

Querying within elements

Within(element) Used to limit the query to the children of the provided element

Example:

from selenium import webdriver
from selenium_testing_library import Screen, Within

screen = Screen(webdriver.Chrome())
parent_element = screen.get_by_css(".container")
Within(parent_element).get_by_title("My title inside the container")

Testing Playground URLs

For debugging using testing-playground, screen exposes log_testing_playground_url() which prints end returns a URL that can be opened in the browser.

# log entire document to testing-playground
url = screen.log_testing_playground_url()
# log a single element
url = screen.log_testing_playground_url(screen.get_by_text("test"))

Contributing

Setting up a local development environment

git clone https://github.com/anze3db/selenium-testing-library.git && cd selenium-testing-library
poetry install && poetry shell
# Make sure `chromedriver` is in your PATH, download from https://chromedriver.chromium.org/downloads
# run tests:
pytest --selenium-headless
# run tests and display coverage info:
pytest --selenium-headless --cov=selenium_testing_library --cov-report html

# To test on multiple Python versions make sure that py37, py38, py39 are
# installed on your system and available through python3.7, python3.8,
# python3.9. (Use pyenv and add the pyenv shims to your path
# `export PATH=$(pyenv root)/shims:$PATH`). Then run tox:
tox

Releasing a new version

1. Update Changelog
2. Update npm dependencies

npm run deploy

If npm run deploy fails because of outdated dependencies run:

npm update

3. Bump the version

bumpver update  # Wait and see if the CI is green

4. Publish to PyPI

poetry build && poetry publish