Intent-based specification tests evaluated by LLM-as-judge. Use when the user asks to "create spec tests", "write intent tests", "TDD with intent", "natural language tests", or wants tests that capture WHY, not just WHAT. NOT pytest/jest/unittest - natural language specs Claude evaluates.
Prevent common testing anti-patterns that undermine test effectiveness and code quality by ensuring tests verify real behavior rather than mock behavior, keeping production code free from test-only pollution, and enforcing thoughtful mocking strategies. Use this skill when writing or modifying any test files (.test.ts, .test.js, .spec.ts, _test.py, test_*.py, *_test.go, *_spec.rb), when adding mock objects, stubs, spies, or test doubles to test suites, when considering adding methods or properties to production classes that are only called from test code, when setting up complex test fixtures or test data, when tests are failing and you're tempted to adjust mocks to make them pass, when deciding how to isolate code under test from external dependencies, when implementing dependency injection or test seams, during code reviews when reviewing test implementation and mocking strategies, when refactoring tests that have become brittle or hard to maintain, when test setup code is becoming longer than the actual te
MUST USE SKILL when creating, modify, validating solidjs code. Following best patterns for SolidJS tests.
Extract structured data from websites using Playwright browser automation
Automates browser interactions using Playwright CLI and templates - takes screenshots, generates PDFs, clicks elements, fills forms, monitors console/network. Use when testing web pages, automating browser tasks, or when user mentions screenshots, web testing, form automation, or Playwright
Write minimal, strategic tests focused on core user flows and critical paths during feature development, deferring comprehensive edge case testing. Use this skill when writing unit tests, integration tests, or end-to-end tests, creating test files (*.test.ts, *.spec.js, __tests__/*), testing critical user workflows, focusing on behavior rather than implementation details, using descriptive test names, mocking external dependencies (databases, APIs, file systems), ensuring tests run quickly, testing business-critical functionality, or determining which tests to write during development versus dedicated testing phases. Apply this skill when completing features at logical milestones, writing tests for primary user flows, or balancing feature development speed with adequate test coverage.
Write the test first, watch it fail, write minimal code to pass (user) - when implementing any feature or bugfix, before writing implementation code
Angular 21+ testing infrastructure with fixtures, ng-mocks, component harness, AAA pattern, and Jest best practices for eliminating duplication
Write minimal, focused tests following KISS and YAGNI principles - test only core user flows during development, defer edge case testing, test behavior not implementation, use clear test names, mock external dependencies, and ensure fast test execution. Use this skill when creating test files, writing unit tests, integration tests, or component tests. Use when working with test frameworks (Jest, Vitest, pytest, RSpec, JUnit, Mocha), when deciding what to test and when, when writing test cases for critical paths and primary workflows, when mocking external services or databases, or when ensuring tests run quickly for developer productivity. Apply when creating test files (.test.ts, .spec.ts, test_*.py, *_test.go) or when implementing behavior-driven test cases.
Use when advanced Pytest features including markers, custom assertions, hooks, and coverage configuration.
Write tests for Rimitive code using Vitest. Use when creating unit tests, integration tests, or test utilities for signals, behaviors, modules, or view components.
Use when implementing any feature or bugfix - requires writing a failing test before writing any production code
Testing strategy for backend use-cases and frontend hooks/UI
Generates tests from features.json test criteria with multi-framework support, coverage analysis, and features.json integration.
Use to build proper go unit tests for services, models, and controllers
Expert knowledge of testing Node.js and Express applications including Jest configuration, Supertest for API testing, unit vs integration vs e2e testing, mocking external APIs, test organization, code coverage, CI/CD integration, and TDD practices. Use when writing tests, setting up testing framework, debugging test failures, or adding test coverage.
Generate small animated GIFs for each Playwright BDD scenario and surface them in-app as usage instructions.
Guide for implementing features using Test-Driven Development (TDD) methodology. Use when: (1) User requests to implement a feature using TDD, (2) User asks to write tests first before implementation, (3) User mentions Red-Green-Refactor cycle, (4) Starting a new feature that requires systematic testing. This skill provides step-by-step TDD workflows, concrete test patterns, and best practices for writing tests before implementation in TypeScript/React projects using Vitest.
Expert guidance for Python testing with pytest framework. Use when (1) writing unit tests or integration tests, (2) setting up test fixtures for setup/teardown, (3) parametrizing tests with multiple inputs, (4) using markers (skip, xfail, custom), (5) mocking/patching with monkeypatch or pytest-mock, (6) configuring pytest (pytest.ini, pyproject.toml, conftest.py), (7) running tests with coverage, (8) debugging test failures, or (9) testing async code, FastAPI, Django, or Flask apps.
