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Testing & modern typing

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

4 matches

How to Benchmark Python Code with pytest-benchmark and mocks

Use pytest-benchmark to measure function performance while combining Mock and patch for controlled test scenarios.

import time
from unittest.mock import Mock, patch

import pytest
from pytest_benchmark.fixture import BenchmarkFixture


def heavy_operation(data: list[int]) -> int:
    """Simulates a CPU-bound operation."""
    return sum(x * x for x in data)


def test_heavy_operation_benchmark(benchmark: BenchmarkFixture) -> None:…

14 0 Open

Testing & modern typing medium

How to Mock a Factory Boy Model Instance in Python

Create a factory boy factory, then patch its Meta.model with a Mock to control instance behavior in tests.

factory-boy mocking unit-testing

Python

import factory
from dataclasses import dataclass
from unittest.mock import Mock, patch
import builtins


@dataclass
class User:
    name: str
    age: int


class UserFactory(factory.Factory):
    class Meta:
        model = User

    name = "Alice"
    age = 30


def get_user_name(user):
    return user.name


def ma…

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Testing & modern typing medium

How to Mock an Object Method in Python unittest

Mock a method on an instance or class with @patch.object, set its return value, and assert its call arguments in Python unittest.

unittest mock patch

Python

import unittest
from unittest.mock import patch

class Calculator:
    def add(self, a, b):
        return a + b
    
    def multiply(self, a, b):
        return a * b

class TestCalculator(unittest.TestCase):
    def test_add_normal(self):
        calc = Calculator()
        result = calc.add(2, 3)
        self.asse…

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Testing & modern typing medium

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…

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