Tools

A disciplined process for hard bugs and performance regressions: build a reliable reproduction loop, reproduce and minimize, form hypotheses, instrument to verify, then fix and add a regression test, redacting secrets in output. By Matt Pocock.

Test-driven development in vertical slices: agree on test seams with the user first, verify behavior only through public interfaces, and avoid listed anti-patterns such as implementation coupling and tautological tests. From Matt Pocock's skills collection.

All-in-one JavaScript and TypeScript toolchain: a single bun binary is a Node.js-compatible runtime, package manager, test runner and script runner, with noticeably faster installs and test runs.

Reference for Vitest 5: config, CLI, the test, describe and expect APIs, hooks, mocking with vi, snapshots, coverage, fixtures, concurrency, filtering and tags, reporters, benchmarks, test environments, type testing and multi-project setups. Generated by Anthony Fu from the official docs.

Official plugin from the Dart and Flutter teams that installs Flutter skills and the Dart MCP server together, covering layered architecture, responsive layouts, layout error fixes, widget and integration tests, routing and internationalization. Requires the Dart/Flutter SDK locally.

Agent skills maintained by the Flutter team: layered architecture, responsive layouts, fixing layout overflows, declarative routing, internationalization, JSON serialization, and widget and integration tests. Works alongside the Dart MCP server.

Testing practices for Vue apps: Vitest and Vue Test Utils, black-box component tests, flushPromises for async code, helpers for testing composables, Pinia stores, async components and Teleport, avoiding snapshot-only tests, and Playwright for end-to-end testing.

Uses hooks to enforce test-driven development in Claude Code: blocks implementation without a failing test, prevents code beyond what tests require, and can use lint results to push refactoring. Needs Node.js 22+. Still maintained, but the author suggests its successor Probity for new projects.

Official testing skills from TestMu AI (formerly LambdaTest) covering 40+ frameworks including Selenium, Playwright, Cypress, Appium, pytest and JUnit, guiding agents to write unit, end-to-end and mobile tests. Runs locally; cloud cross-browser and real-device runs need an account.