pytest-bdd Cheat Sheet

Recommendations

Before using this cheat sheet:

• Learn the following about Gherkin:
  • Feature, Scenario
  • Given, When, Then
  • Scenario Outline, Examples
  • Tags
  • Comments
• For people without any Python experience, learn basic syntax of Python such as:
  • indentation
  • commenting
  • declarition of variables and functions
• Read through the official document: pytest-bdd.pdf .

Setup

1. Install python environment

2. Install pip

1. Download get-pip.py
2. Run following command:

python get-pip.py

3. Upgrade pip

pip install -U pip

3. Instal pytest

pip install -U pytest

4. Install pytest-bdd

pip install pytest-bdd

5. Install selenium

pip install selenium

6. Download a webdriver

• chromedriver
• fireboxdriver
• etc.

Write feature files

• Template

# This is a comment
@aTag @anotherTag @etc...
Feature: some description ...
  Scenario: some description ...
    Given ...
    When ...
    Then ...
    And ...

• Scenario Outline

#pageTitle.feature
Feature: Check the page title
  Scenario Outline: Check page title for XX page
    Given I am on the zoo website
    When I navigate to <xx_link>
    Then I check page title is "<xx>"
    And I close the browser
    Examples:
    |xx_link        |xx       |
    |adoption_link  |Adoption |
    |about_link     |About    |
    |contact_link   |Contact  |

• Vertical example table

Scenario Outline: Outlined given, when, thens 
  Given there are <start> cucumbers
  When I eat <eat> cucumbers
  Then I should have <left> cucumbers
  Examples: Vertical
  | start | 12 | 2  | 
  | eat   | 5  | 1  |  
  | left  | 7  | 1  |

Generate test files

NOTICE:

• A test file and its corresponding feature file MUST stay in the same dirctory
• The name of a test file MUST be in the form of test_*.py or *_test.py
• According to the previous sentence, And statement will be autometically modified to given, when, or then statement in the test file. • Create fully functional but of course empty tests and step definitions for given a feature file.

pytest-bdd generate someFeature.feature

• Redirect the generated code to a test file.

pytest-bdd generate pageTitle.feature > test_some_feature.py

• Advanced code generation

py.test --generate-missing --feature features tests/functional

Modify test files

• import

from pytest_bdd import (given, scenario, then, when)
import pytest
from selenium import webdriver

• Fixture for driver setup

Allow the browser automaticlly run before executing tests and quit after all the tests finished.

@pytest.fixture(autouse=True, scope='function')
def setup(request):
    global driver
    driver = webdriver.Chrome("/Users/yuxuan.zhao/chromedriver")
    def fin():
        driver.quit()
        request.addfinalizer(fin)

• Step definition

• Step aliases

@given('I am on the zoo website')
@given('I am on the homepage of zoo website')
def i_am_on_the_zoo_website():
    """I am on the zoo website."""
    driver.get("http://www.thetestroom.com/webapp/")

• Step arguments

@when('I navigate to <xx_link>')
def i_navigate_to_xx_link(xx_link):
    """I navigate to <xx_link>."""
    driver.find_element_by_id(xx_link).click()

• Driver usage
  • Navigate to a page given by the URL

driver.get("http://www.python.org")  

• An assertion to confirm that title has “Python” word in it

assert "Python" in driver.title

• Find an element

elem = driver.find_element_by_name("q")
# find_element_by_id
# find_element_by_name
# find_element_by_link_text
# find_element_by_partial_link_text
# etc..

• Clear filds

elem.clear()

• Send keys

from selenium.webdriver.common.keys import Keys
elem.send_keys("pycon")

See more information in the official document: selenium-python.pdf

Run the tests

• Run all the tests

pytest

• Run a specified file

pytest test_something.py

• Run tests with sepcific tags

pytest -k "Tag1 and Tag2 and Tag3"

• Run tests without a certain tag

pytest -k "not Tag1"

Report

To have an output in json format:

py.test --cucumberjson=<path to json report>

Example

https://github.com/VirtaKuivapuu/pytest-bdd-example