自动化测试（一）pytest

1、断言引发了异常

def test_foo_not_implemented():
    def foo():
        raise NotImplementedError

    with pytest.raises(RuntimeError) as excinfo:
        foo()
    assert excinfo.type is RuntimeError

2、夹具
（1）测试可请求夹具多次（夹具返回值会被缓存）

# contents of test_append.py
import pytest

# Arrange
@pytest.fixture
def first_entry():
    return "a"

# Arrange
@pytest.fixture
def order():
    return []

# Act
@pytest.fixture
def append_first(order, first_entry):
    return order.append(first_entry)

def test_string_only(append_first, order, first_entry):
    # Assert
    assert order == [first_entry]

scope="function"表示每个测试函数运行时会新建一次order实例。但在同一个测试函数中，所有对order的请求会共享同一个实例（缓存机制）
（2）安全夹具结构
最安全、最简单的夹具结构要求将夹具限制为每次仅执行一个状态更改操作，然后将其与其清理代码捆绑在一起

from uuid import uuid4
from urllib.parse import urljoin

from selenium.webdriver import Chrome
import pytest

from src.utils.pages import LoginPage, LandingPage
from src.utils import AdminApiClient
from src.utils.data_types import User

@pytest.fixture
def admin_client(base_url, admin_credentials):
    return AdminApiClient(base_url, **admin_credentials)

@pytest.fixture
def user(admin_client):
    _user = User(name="Susan", username=f"testuser-{uuid4()}", password="P4$$word")
    admin_client.create_user(_user)
    yield _user
    admin_client.delete_user(_user)

@pytest.fixture
def driver():
    _driver = Chrome()
    yield _driver
    _driver.quit()

@pytest.fixture
def login(driver, base_url, user):
    driver.get(urljoin(base_url, "/login"))
    page = LoginPage(driver)
    page.login(user)

@pytest.fixture
def landing_page(driver, login):
    return LandingPage(driver)

def test_name_on_landing_page_after_login(landing_page, user):
    assert landing_page.header == f"Welcome, {user.name}!"

（3）安全运行多个assert语句

# contents of tests/end_to_end/test_login.py
from uuid import uuid4
from urllib.parse import urljoin

from selenium.webdriver import Chrome
import pytest

from src.utils.pages import LoginPage, LandingPage
from src.utils import AdminApiClient
from src.utils.data_types import User

@pytest.fixture(scope="class")
def admin_client(base_url, admin_credentials):
    return AdminApiClient(base_url, **admin_credentials)

@pytest.fixture(scope="class")
def user(admin_client):
    _user = User(name="Susan", username=f"testuser-{uuid4()}", password="P4$$word")
    admin_client.create_user(_user)
    yield _user
    admin_client.delete_user(_user)

@pytest.fixture(scope="class")
def driver():
    _driver = Chrome()
    yield _driver
    _driver.quit()

@pytest.fixture(scope="class")
def landing_page(driver, login):
    return LandingPage(driver)

class TestLandingPageSuccess:
    @pytest.fixture(scope="class", autouse=True)
    def login(self, driver, base_url, user):
        driver.get(urljoin(base_url, "/login"))
        page = LoginPage(driver)
        page.login(user)

    def test_name_in_header(self, landing_page, user):
        assert landing_page.header == f"Welcome, {user.name}!"

    def test_sign_out_button(self, landing_page):
        assert landing_page.sign_out_button.is_displayed()

    def test_profile_link(self, landing_page, user):
        profile_href = urljoin(base_url, f"/profile?id={user.profile_id}")
        assert landing_page.profile_link.get_attribute("href") == profile_href

login夹具在类内autouse自动使用，assert语句分开设计用例，每个assert语句专注于一个特定的测试点，提高可读性、可维护性、准确性

（3）参数化夹具

# content of conftest.py
import smtplib

import pytest

@pytest.fixture(scope="module", params=["smtp.gmail.com", "mail.python.org"])
def smtp_connection(request):
    smtp_connection = smtplib.SMTP(request.param, 587, timeout=5)
    yield smtp_connection
    print(f"finalizing {smtp_connection}")
    smtp_connection.close()

3、使用@pytest.mark.parametrize对测试函数进行参数化