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Testing & modern typing

pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.

4 matches

How to Mock and Stub API Calls in Playwright E2E Tests with Python

This code demonstrates how to mock and stub API responses in Playwright end-to-end tests using Python's unittest.mock patch and Playwright's APIRequestContext.

playwright e2e-testing mocking

Python

import re
from unittest.mock import patch
from playwright.sync_api import sync_playwright

def verify_api_mock(page, mock_url, mock_response):
    with patch("playwright.sync_api.APIRequestContext.get") as mock_get:
        mock_get.return_value.json.return_value = mock_response
        mock_get.return_value.status_co…

14 0 Open

Testing & modern typing medium

How to Run an Integration Test with Docker Compose Mock in Python

Run a Python integration test against a docker-compose environment, using mocks to simulate service health and business logic responses.

docker integration-testing mocking

Python

import subprocess
import json
from typing import Dict

def run_integration_test() -> Dict[str, str]:
    """
    Simulates an integration test against a docker-compose environment
    using a mock service that returns canned responses.
    """
    # Mock docker-compose environment check
    env_ready = subprocess.run(…

15 0 Open

Testing & modern typing easy

How to Write a Contract Test with Mock in Python

Use unittest.mock to verify a consumer's expectations match the provider's response shape in a Python contract test.

contract-testing unittest mock

Python

from unittest.mock import Mock

# Contract test: verify consumer expects data shape that provider delivers.
# We mock the provider and assert the consumer's calls match the agreed contract.

def fetch_user(provider_client, user_id):
    """Consumer code: expects provider to return {'id', 'name', 'email'}."""
    respo…

13 0 Open

Testing & modern typing easy

How to Write a Fast Smoke Test for a Critical Path in Python

A quick smoke test that validates the /health critical path executes fast enough, raising errors on wrong paths or slow responses.

smoke-test performance health-check

Python

import time

def smoke_test(path):
    if path != "/health":
        raise ValueError("Critical path expected /health")
    start = time.perf_counter()
    # Simulate the critical health check work
    time.sleep(0.01)
    elapsed = time.perf_counter() - start
    if elapsed > 0.05:
        raise RuntimeError("Health …

12 0 Open

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