API 測試

簡介

Playwright 可以用來存取你的應用程式的 REST API。

有時候你可能想直接從 Python 發送請求到伺服器，而不需要加載頁面並執行 js 程式碼。以下是一些可能派上用場的範例:

• 測試你的伺服器 API。
• 在測試中訪問 web 應用程式之前準備伺服器端狀態。
• 在瀏覽器中執行一些操作後驗證伺服器端後置條件。

所有這些都可以通過 APIRequestContext 方法實現。

以下範例依賴 pytest-playwright 套件，該套件為 Pytest 測試執行器添加 Playwright 固定裝置。

撰寫 API 測試

APIRequestContext 可以透過網路發送各種 HTTP(S) 請求。

以下範例展示如何使用 Playwright 測試通過 GitHub API 建立問題。測試套件將執行以下操作：

• 建立一個新的儲存庫後執行測試。
• 建立一些問題並驗證伺服器狀態。
• 執行測試後刪除儲存庫。

設定

GitHub API 需要授權，所以我們將為所有測試設定一次 token。在此同時，我們也會設定 baseURL 來簡化測試。

import os
from typing import Generator

import pytest
from playwright.sync_api import Playwright, APIRequestContext

GITHUB_API_TOKEN = os.getenv("GITHUB_API_TOKEN")
assert GITHUB_API_TOKEN, "GITHUB_API_TOKEN is not set"


@pytest.fixture(scope="session")
def api_request_context(
    playwright: Playwright,
) -> Generator[APIRequestContext, None, None]:
    headers = {
        # We set this header per GitHub guidelines.
        "Accept": "application/vnd.github.v3+json",
        # Add authorization token to all requests.
        # Assuming personal access token available in the environment.
        "Authorization": f"token {GITHUB_API_TOKEN}",
    }
    request_context = playwright.request.new_context(
        base_url="https://api.github.com", extra_http_headers=headers
    )
    yield request_context
    request_context.dispose()

撰寫測試

現在我們已經初始化了請求物件，我們可以新增一些測試，這些測試將在存放庫中建立新的問題。

import os
from typing import Generator

import pytest
from playwright.sync_api import Playwright, APIRequestContext

GITHUB_API_TOKEN = os.getenv("GITHUB_API_TOKEN")
assert GITHUB_API_TOKEN, "GITHUB_API_TOKEN is not set"

GITHUB_USER = os.getenv("GITHUB_USER")
assert GITHUB_USER, "GITHUB_USER is not set"

GITHUB_REPO = "test"

# ...

def test_should_create_bug_report(api_request_context: APIRequestContext) -> None:
    data = {
        "title": "[Bug] report 1",
        "body": "Bug description",
    }
    new_issue = api_request_context.post(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues", data=data)
    assert new_issue.ok

    issues = api_request_context.get(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues")
    assert issues.ok
    issues_response = issues.json()
    issue = list(filter(lambda issue: issue["title"] == "[Bug] report 1", issues_response))[0]
    assert issue
    assert issue["body"] == "Bug description"

def test_should_create_feature_request(api_request_context: APIRequestContext) -> None:
    data = {
        "title": "[Feature] request 1",
        "body": "Feature description",
    }
    new_issue = api_request_context.post(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues", data=data)
    assert new_issue.ok

    issues = api_request_context.get(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues")
    assert issues.ok
    issues_response = issues.json()
    issue = list(filter(lambda issue: issue["title"] == "[Feature] request 1", issues_response))[0]
    assert issue
    assert issue["body"] == "Feature description"

設定和拆卸

這些測試假設資源庫已存在。您可能想在執行測試之前建立一個新的，並在之後刪除它。為此，請使用 session fixture。yield 之前的部分是所有之前的部分，之後的部分是所有之後的部分。

# ...
@pytest.fixture(scope="session", autouse=True)
def create_test_repository(
    api_request_context: APIRequestContext,
) -> Generator[None, None, None]:
    # Before all
    new_repo = api_request_context.post("/user/repos", data={"name": GITHUB_REPO})
    assert new_repo.ok
    yield
    # After all
    deleted_repo = api_request_context.delete(f"/repos/{GITHUB_USER}/{GITHUB_REPO}")
    assert deleted_repo.ok

完整測試範例

以下是一個 API 測試的完整範例:

from enum import auto
import os
from typing import Generator

import pytest
from playwright.sync_api import Playwright, Page, APIRequestContext, expect

GITHUB_API_TOKEN = os.getenv("GITHUB_API_TOKEN")
assert GITHUB_API_TOKEN, "GITHUB_API_TOKEN is not set"

GITHUB_USER = os.getenv("GITHUB_USER")
assert GITHUB_USER, "GITHUB_USER is not set"

GITHUB_REPO = "test"


@pytest.fixture(scope="session")
def api_request_context(
    playwright: Playwright,
) -> Generator[APIRequestContext, None, None]:
    headers = {
        # We set this header per GitHub guidelines.
        "Accept": "application/vnd.github.v3+json",
        # Add authorization token to all requests.
        # Assuming personal access token available in the environment.
        "Authorization": f"token {GITHUB_API_TOKEN}",
    }
    request_context = playwright.request.new_context(
        base_url="https://api.github.com", extra_http_headers=headers
    )
    yield request_context
    request_context.dispose()


@pytest.fixture(scope="session", autouse=True)
def create_test_repository(
    api_request_context: APIRequestContext,
) -> Generator[None, None, None]:
    # Before all
    new_repo = api_request_context.post("/user/repos", data={"name": GITHUB_REPO})
    assert new_repo.ok
    yield
    # After all
    deleted_repo = api_request_context.delete(f"/repos/{GITHUB_USER}/{GITHUB_REPO}")
    assert deleted_repo.ok


def test_should_create_bug_report(api_request_context: APIRequestContext) -> None:
    data = {
        "title": "[Bug] report 1",
        "body": "Bug description",
    }
    new_issue = api_request_context.post(
        f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues", data=data
    )
    assert new_issue.ok

    issues = api_request_context.get(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues")
    assert issues.ok
    issues_response = issues.json()
    issue = list(
        filter(lambda issue: issue["title"] == "[Bug] report 1", issues_response)
    )[0]
    assert issue
    assert issue["body"] == "Bug description"


def test_should_create_feature_request(api_request_context: APIRequestContext) -> None:
    data = {
        "title": "[Feature] request 1",
        "body": "Feature description",
    }
    new_issue = api_request_context.post(
        f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues", data=data
    )
    assert new_issue.ok

    issues = api_request_context.get(f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues")
    assert issues.ok
    issues_response = issues.json()
    issue = list(
        filter(lambda issue: issue["title"] == "[Feature] request 1", issues_response)
    )[0]
    assert issue
    assert issue["body"] == "Feature description"

通過 API 呼叫準備伺服器狀態

以下測試通過 API 建立一個新問題，然後導航到專案中所有問題的列表，以檢查它是否出現在列表的頂部。檢查是使用 LocatorAssertions 進行的。

def test_last_created_issue_should_be_first_in_the_list(api_request_context: APIRequestContext, page: Page) -> None:
    def create_issue(title: str) -> None:
        data = {
            "title": title,
            "body": "Feature description",
        }
        new_issue = api_request_context.post(
            f"/repos/{GITHUB_USER}/{GITHUB_REPO}/issues", data=data
        )
        assert new_issue.ok
    create_issue("[Feature] request 1")
    create_issue("[Feature] request 2")
    page.goto(f"https://github.com/{GITHUB_USER}/{GITHUB_REPO}/issues")
    first_issue = page.locator("a[data-hovercard-type='issue']").first
    expect(first_issue).to_have_text("[Feature] request 2")

執行用戶操作後檢查伺服器狀態

以下測試通過瀏覽器中的使用者介面建立一個新問題，然後通過 API 檢查是否已建立:

def test_last_created_issue_should_be_on_the_server(api_request_context: APIRequestContext, page: Page) -> None:
    page.goto(f"https://github.com/{GITHUB_USER}/{GITHUB_REPO}/issues")
    page.locator("text=New issue").click()
    page.locator("[aria-label='Title']").fill("Bug report 1")
    page.locator("[aria-label='Comment body']").fill("Bug description")
    page.locator("text=Submit new issue").click()
    issue_id = page.url.split("/")[-1]

    new_issue = api_request_context.get(f"https://github.com/{GITHUB_USER}/{GITHUB_REPO}/issues/{issue_id}")
    assert new_issue.ok
    assert new_issue.json()["title"] == "[Bug] report 1"
    assert new_issue.json()["body"] == "Bug description"

重用身份驗證狀態

Web apps 使用基於 cookie 或基於 token 的身份驗證，已驗證的狀態存儲為 cookies。Playwright 提供 api_request_context.storage_state() 方法，可以用來從已驗證的上下文中檢索存儲狀態，然後使用該狀態建立新的上下文。

儲存狀態在 BrowserContext 和 APIRequestContext 之間是可互換的。你可以使用它通過 API 呼叫登入，然後建立一個已經包含 cookies 的新 context。以下程式碼片段從已驗證的 APIRequestContext 中檢索狀態，並使用該狀態建立一個新的 BrowserContext。

request_context = playwright.request.new_context(http_credentials={"username": "test", "password": "test"})
request_context.get("https://api.example.com/login")
# Save storage state into a variable.
state = request_context.storage_state()

# Create a new context with the saved storage state.
context = browser.new_context(storage_state=state)