Behave BDD Skill

Core Patterns

Feature File (features/login.feature)

Feature: User Login
  As a registered user
  I want to log into the application

  Background:
    Given I am on the login page

  Scenario: Successful login
    When I enter "user@test.com" as email
    And I enter "password123" as password
    And I click login
    Then I should see the dashboard
    And the welcome message should say "Welcome"

  Scenario: Invalid credentials
    When I enter "wrong@test.com" as email
    And I enter "wrong" as password
    And I click login
    Then I should see error "Invalid credentials"

  Scenario Outline: Login with various users
    When I enter "<email>" as email
    And I enter "<password>" as password
    And I click login
    Then I should see "<result>"

    Examples:
      | email          | password | result    |
      | admin@test.com | admin123 | Dashboard |
      | bad@test.com   | wrong    | Error     |

Step Definitions (features/steps/login_steps.py)

from behave import given, when, then
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

@given('I am on the login page')
def step_on_login(context):
    context.browser.get(context.base_url + '/login')

@when('I enter "{text}" as email')
def step_enter_email(context, text):
    el = context.browser.find_element(By.ID, 'email')
    el.clear()
    el.send_keys(text)

@when('I enter "{text}" as password')
def step_enter_password(context, text):
    el = context.browser.find_element(By.ID, 'password')
    el.clear()
    el.send_keys(text)

@when('I click login')
def step_click_login(context):
    context.browser.find_element(By.CSS_SELECTOR, 'button[type="submit"]').click()

@then('I should see the dashboard')
def step_see_dashboard(context):
    WebDriverWait(context.browser, 10).until(
        EC.url_contains('/dashboard')
    )
    assert '/dashboard' in context.browser.current_url

@then('I should see error "{msg}"')
def step_see_error(context, msg):
    error = WebDriverWait(context.browser, 5).until(
        EC.visibility_of_element_located((By.CSS_SELECTOR, '.error'))
    )
    assert msg in error.text

Environment Hooks (features/environment.py)

from selenium import webdriver

def before_all(context):
    context.base_url = 'http://localhost:3000'

def before_scenario(context, scenario):
    context.browser = webdriver.Chrome()
    context.browser.implicitly_wait(10)

def after_scenario(context, scenario):
    if scenario.status == 'failed':
        context.browser.save_screenshot(f'screenshots/{scenario.name}.png')
    context.browser.quit()

Tags

@smoke
Feature: Login
  @critical
  Scenario: ...

behave --tags=@smoke
behave --tags="@smoke and not @slow"

Setup: pip install behave selenium

Run: behave or behave features/login.feature

Cloud Execution on TestMu AI

Set environment variables: LT_USERNAME, LT_ACCESS_KEY

# environment.py
from selenium import webdriver
import os

def before_scenario(context, scenario):
    lt_options = {
        "user": os.environ["LT_USERNAME"],
        "accessKey": os.environ["LT_ACCESS_KEY"],
        "build": "Behave Build",
        "name": scenario.name,
        "platformName": "Windows 11",
        "video": True,
        "console": True,
        "network": True,
    }
    options = webdriver.ChromeOptions()
    options.set_capability("LT:Options", lt_options)
    context.driver = webdriver.Remote(
        command_executor=f"https://{os.environ['LT_USERNAME']}:{os.environ['LT_ACCESS_KEY']}@hub.lambdatest.com/wd/hub",
        options=options,
    )

Report: behave --format json -o report.json

Deep Patterns

See reference/playbook.md for production-grade patterns: