Blog

pytest-mock vs monkeypatch in 2026: Which to Use & When

pytest-mock's mocker fixture vs pytest's built-in monkeypatch in 2026 — what each does, when to pick which, auto-teardown, spies, and full code examples.

Python

PyUnit vs pytest 2026: stdlib unittest or the third-party favorite

PyUnit vs pytest in 2026: PyUnit is Python's built-in unittest. Compare assertions, fixtures, parametrization, and discovery to pick the right framework.

React Testing Library Common Mistakes to Avoid in 2026

Fix the most common React Testing Library mistakes in 2026 — the "not wrapped in act()" warning, getByRole priority, waitFor misuse, and cleanup pitfalls.

Reviewing AI-Generated Tests: A Code-Review Checklist 2026

A practical code-review checklist for AI-generated tests from Claude Code, Cursor, and Copilot — catch tautologies, weak assertions, and fake coverage.

Rubric-Based LLM Evaluation Guide: G-Eval (2026)

Rubric-based LLM evaluation in 2026: design scoring criteria, use G-Eval and an LLM judge, write custom rubrics, and avoid judge bias. With code.

Sinon Stubs vs Spies vs Mocks: JavaScript Guide 2026

Sinon.JS stubs vs spies vs mocks explained for 2026 — when to use each, sandboxes for cleanup, fake timers, and real, copy-paste test code examples.

CI/CD

SonarQube Quality Gates for Testing & Coverage (2026)

Configure SonarQube quality gates in 2026 to enforce test coverage and quality — Clean as You Code, new-code conditions, coverage import, and CI setup.

API Testing

Spectral OpenAPI Linting Guide: Govern API Specs in CI (2026)

Learn Spectral OpenAPI linting: install the CLI, write custom rulesets, fail CI on spec violations, and enforce API governance across teams in 2026.

Java

Spock Framework Groovy Testing Guide (2026)

A practical Spock framework guide for Groovy: given/when/then blocks, data-driven tests with where: tables, mocks and stubs, and JUnit 5 setup.

State Transition Testing Guide with Diagrams & Examples

Learn state transition testing with diagrams, state tables, and worked examples. Cover 0-switch and 1-switch coverage, invalid transitions, and parametrized tests.

Stub vs Mock vs Spy vs Fake: Test Doubles Explained

Test doubles explained: the difference between dummy, stub, spy, mock, and fake, with code examples and guidance on when to use each in 2026.

SWE-bench Explained: The Coding Agent Benchmark (2026)

SWE-bench explained for 2026: how this benchmark turns real GitHub issues into coding-agent tasks, how patches are scored, plus Verified and Lite subsets.

Taming LLM Non-Determinism & Flaky Evals (2026 Guide)

Fix flaky LLM evals in 2026: why outputs vary, temperature and seeds, tolerance bands, semantic assertions, and majority-vote scoring for stable results.

Terminal-Bench Guide: Benchmarking AI Agents (2026)

Terminal-Bench guide for 2026: how the benchmark scores AI agents on real terminal tasks via Docker sandboxes, end-state verification tests, and adapters.

Test Smells & Anti-Patterns Guide: How to Refactor (2026)

Spot common test smells and unit-testing anti-patterns, understand why they hurt, and refactor them with before/after code in Python, JS, and Java.

Testify Tutorial: Go Assertions, Mocks & Suites (2026)

Testify tutorial for Go in 2026 — assert vs require, the mock package, testify/suite lifecycle, and runnable examples for cleaner Go tests on top of testing.

Comparison

Testify vs Ginkgo + Gomega: Go Testing (2026)

Testify vs Ginkgo + Gomega compared for Go in 2026 — classic table-driven vs BDD, feature matrix, code, parallelism, and when to pick each framework.

Comparison

testRigor vs Playwright 2026: Codeless AI vs Code-Based OSS

testRigor vs Playwright in 2026 — testRigor is codeless, AI, plain-English SaaS; Playwright is free, code-based OSS. See which fits your team, with examples.

Tool Calling Accuracy Testing Guide for LLMs (2026)

Test LLM tool-calling accuracy in 2026: measure tool selection, argument correctness, and JSON schema adherence with a reproducible eval harness and CI gates.

Vitest 3 to 4 Migration Guide 2026: Upgrade Without Breaking Your Suite

A safe, step-by-step Vitest 3 to 4 migration guide. Bump packages in lockstep, fix config and breaking changes, verify coverage, and roll back cleanly.

Vitest Config Setup Guide 2026: vitest.config.ts Explained

Configure vitest.config.ts in 2026 — test.globals, environment, setupFiles, projects, include/exclude, aliases, and coverage. Copy-paste working configs.

Vitest Coverage 2026: v8 vs Istanbul, Thresholds & Reporters

Vitest coverage in 2026 — v8 vs istanbul providers compared, configuring thresholds, choosing reporters (html, lcov, json), include/exclude, and CI gates.

Playwright

What's New in Playwright 2026: AI Agents, MCP, and Accessibility-First Testing

A practical overview of what's new in Playwright 2026 — test agents, the MCP server, ARIA snapshots, Trace Viewer, component testing, the Clock API, and more.

Java

WireMock Java & Spring Boot Testing Guide (2026)

WireMock for Java and Spring Boot: stub HTTP APIs, the JUnit 5 extension, request matching, response templating, verification, and integration test setup.

Mobile

XCUITest iOS UI Testing Tutorial (2026)

XCUITest iOS UI testing tutorial for 2026: XCUIApplication, element queries, taps and typing, assertions, waitForExistence, system alerts, and CI with xcodebuild.

.NET

xUnit vs NUnit vs MSTest in 2026: .NET Testing Compared

xUnit vs NUnit vs MSTest compared for 2026 — attributes, parallelism, parameterized tests, assertions, and a decision matrix to pick the right .NET test framework.

τ-bench (tau-bench) Agent Evaluation Guide (2026)

A 2026 guide to tau-bench (τ-bench): how Sierra's tool-agent-user benchmark works across retail and airline domains, and how pass^k measures reliability.

Maestro Mobile Testing: The Complete YAML-Based Guide for 2026

Master Maestro mobile testing in 2026: install the CLI, write YAML flows, use selectors, conditionals, loops, JS, Maestro Studio, Maestro Cloud, GitHub Actions CI, and compare it to Appium and Detox.

MSW Mock Service Worker: Complete Guide for 2026 (v2)

Master Mock Service Worker (MSW) v2 in 2026: http handlers, HttpResponse.json, setupServer vs setupWorker, runtime overrides, GraphQL mocking, plus Vitest and Playwright integration.

Pact Contract Testing: The Complete 2026 Guide (Pact JS)

Master Pact contract testing in 2026: consumer-driven contracts, PactV4 and MatchersV3, provider verification, Pact Broker, can-i-deploy, provider states, and bi-directional contracts.

Playwright Network Interception with route(): Complete Reference

A full Playwright page.route() reference: fulfill, abort, continue, glob vs regex matching, mocking JSON APIs, routeFromHAR, waitForResponse, GraphQL, and CI tips.

Pytest Fixtures Scope: The Complete Guide (2026)

Master pytest fixtures and scope: function, class, module, package, session, yield teardown, conftest.py sharing, autouse, params, factory fixtures, and dynamic scope.

Vitest Browser Mode: The Complete Guide (2026)

Vitest 4 Browser Mode is stable. Learn setup with Playwright, component tests with page and userEvent, locators, assertions, headless CI, screenshots, and jsdom vs E2E.

GitHub Actions Playwright Matrix & Sharding Guide (2026)

Run Playwright in CI with GitHub Actions: a complete matrix workflow with browser and shard parallelism, caching, blob report merge, and HTML artifacts.

Playwright Soft Assertions with expect.soft -- 2026 Guide

Master Playwright soft assertions: expect.soft, expect.configure soft mode, test.info().errors, combining hard and soft assertions, and custom messages.

Prompt Injection Testing: A Practical Guide (2026)

Hands-on prompt injection testing with Python and Promptfoo: direct and indirect attacks, jailbreak payloads, prompt-leak detection, and refusal assertions.

Pytest Coverage with pytest-cov: Complete 2026 Guide

Measure pytest code coverage with pytest-cov: --cov, pyproject.toml config, branch coverage, HTML/XML reports, --cov-fail-under, and combining in CI.

Pytest Fixtures and conftest.py: The Complete Guide (2026)

Master pytest fixtures, conftest.py, fixture scope, and yield teardown with runnable examples in this practical, complete pytest fixtures tutorial for 2026.

Pytest Parametrize: The Complete Guide for 2026 (with Examples)

Master pytest.mark.parametrize with runnable examples: multiple arguments, custom ids, stacking, parametrizing fixtures, and data-driven testing patterns.

Schemathesis Tutorial: OpenAPI Fuzzing & Contract Testing

Learn Schemathesis for API property-based testing and OpenAPI fuzzing. Run the CLI, use the pytest plugin, add stateful testing, hooks, checks, and CI.

Selenium 4 Relative Locators -- The Complete 2026 Guide

Master Selenium 4 relative locators with real Java and Python code: above, below, toLeftOf, toRightOf, near, chaining, limitations, and friendly locators.

Vitest Mocking with vi.mock: The Complete 2026 Guide

Master Vitest mocking: vi.fn, vi.spyOn, vi.mock module mocking, importActual partial mocks, fake timers, mocking fetch and axios, and vi.hoisted.

@axe-core/playwright Accessibility Testing Reference 2026

Complete @axe-core/playwright accessibility testing reference: AxeBuilder, analyze, WCAG tags, include/exclude scoping, disabling rules, CI gating, fixtures.

Arize Phoenix: LLM Tracing + Evaluations Guide 2026

Arize Phoenix guide: launch the app, auto-instrument tracing with OpenInference, run evaluations with phoenix.evals, and log eval results back onto spans.

DeepEval RAG Evaluation Metrics Complete Reference 2026

Complete DeepEval RAG evaluation metrics reference: answer relevancy, faithfulness, contextual precision, recall, relevancy, plus runnable pytest code.

OpenAI Agent Evals: Datasets + Traces Workflow Guide 2026

End-to-end OpenAI agent evals workflow: build JSONL datasets, capture traces, attach graders, run evals on an agent, and read the report. Runnable SDK code.

OpenAI Evals Graders Reference 2026: Model, String, Python

Complete OpenAI Evals graders reference: string-check, text-similarity, model graders (LLM-as-judge), and python graders. Runnable SDK and curl examples.

Ragas Faithfulness, Context Precision, Recall Reference 2026

Complete 2026 Ragas reference: faithfulness, answer relevancy, context precision, context recall and entity recall with runnable Python and score interpretation.

Selenium Manager 4.6+ Driver Management 2026 Guide

Selenium Manager 4.6+ guide to automatic driver management: version resolution, the ~/.cache/selenium cache, offline mode, proxy config, the CLI, and CI setup.