Testing

12-month change compares the average of the last 4 weeks of downloads with the first 4 weeks of the 52-week series. Gzip size is for the whole package, as measured by Bundlephobia. "-" means the value has not been fetched.

• @stuntman/serverStuntman - HTTP proxy / mock server with API
• @stdlib/assert-is-windowsBoolean indicating if the current process is running on Windows.
• @stdlib/complex-base-assert-is-almost-same-valueTest whether two complex numbers are approximately the same value within a specified number of ULPs (units in the last place).
• @aryzing/bun-mock-fetchMock fetch requests in Bun.
• svelte-fragment-componentSvelte component that renders its children with lifecycle hooks to simplify testing
• @yarn-tool/find-root尋找 Yarn workspace 根目錄的工具，提供路徑驗證、錯誤處理和斷言函數 (Find Yarn workspace root directory with path validation, error handling, and assertion functions)
• @stdlib/assert-is-almost-same-valueTest if two arguments are approximately the same value within a specified number of ULPs (units in the last place).
• mentossA utility to mock fetch requests and responses.
• @flakiness/jestA custom Jest reporter that generates Flakiness Reports from your test runs
• bupkisUncommonly extensible assertions for the beautiful people
• manten満点 - Lightweight testing library for Node.js
• @reown/appkit-testingThe full stack toolkit to build onchain app UX.
• @web/test-runner-browserstackBrowserstack launcher for Web Test Runner
• open-agents-aiAI coding agent powered by open-source models (Ollama/vLLM) — interactive TUI with agentic tool-calling loop
• @getmocha/users-serviceAn API client, Hono middleware, and a React provider for the Mocha Users Service
• @se-studio/ab-testingServer-side A/B testing framework for Next.js applications with Contentful CMS
• mocktownRecord an app's outbound traffic, serve it back as stateful mocks, and keep them alive as the real services change.
• tiny-fixturesSimple database fixtures
• idb-opfsReplace navigator.storage.getDirectory() with a IndexedBD-backed OPFS implementation. Based on opfs-mock.
• playwright-personaAuthentication in Playwright using personas.
• cypress-intercept-searchA Cypress plugin to recursively search your intercepted requests/responses by key/value
• vitest-mobileRun Vitest component tests inside a real React Native app with native touch synthesis
• nanospySpy and mock methods in tests with great TypeScript support
• assert-json-bodyOpenAPI response body extraction and JSON shape assertion toolkit (framework-agnostic)
• gulp-qunitRun QUnit unit tests in a headless PhantomJS instance.
• @stdlib/ndarray-base-assert-is-read-onlyTest if an ndarray is read-only.
• @stdlib/ndarray-base-assert-is-equal-data-typeTest whether two values are equal data types.
• nixtSimple and powerful testing for command-line apps
• protractor-http-clientHTTP client to be used in protractor tests
• chai-jsonA chai plugin to validate json files
• env-testSets NODE_ENV to 'test'
• enzyme-adapter-react-17-updatedUnofficial adapter for React 17 for [Enzyme]
• @upyo/mockMock transport for Upyo email library—useful for testing
• @daisy/axe-core-for-aceAccessibility engine for automated Web UI testing
• react-native-mock-renderA fork of react-native-mock that renders components
• sequelize-mock-v5A simple mock interface specifically for testing code relying on Sequelize models
• @stdlib/assert-is-empty-collectionTest if a value is an empty collection.
• @stdlib/ndarray-base-assert-is-signed-integer-data-typeTest if an input value is a supported ndarray signed integer data type.
• rollup-jestRollup preprocessor for Jest
• svelte-htmtagged template syntax for svelte to simplify testing
• @stdlib/ndarray-base-assert-is-unsigned-integer-data-typeTest if an input value is a supported ndarray unsigned integer data type.
• @stdlib/ndarray-base-assert-is-real-floating-point-data-typeTest if an input value is a supported ndarray real-valued floating-point data type.
• @stdlib/ndarray-base-assert-is-boolean-data-typeTest if an input value is a supported ndarray boolean data type.
• @twin.org/blob-storage-connector-memoryProvides an in-memory connector for fast local testing and ephemeral blob workflows.
• @openzeppelin/test-environmentOne-line setup for an awesome testing experience.
• @volter/twin-stripeLocal Stripe twin — a faithful, stateful local Stripe API your real `stripe` SDK talks to unmodified. Mirror, simulate, and fork. Built on @volter/twin.
• @hot-teapot/mock-yardA browser devtools panel for MSW, built for orval + Faker. Toggle mocked endpoints, switch success/empty/error/custom scenarios, tweak latency & status, and inspect traffic — without touching code.
• chai-changesChange assertions for the Chai assertion library
• cjs-mockNodeJS module mocking for CJS (CommonJS) modules for unit testing purposes.
• browser-cache-mocka mock for the browser cache that can be used in a node environment

• selenium-webdriver vs wd
• @appium/types vs selenium-webdriver
• msw vs json-server
• @copilotkit/aimock vs mock-socket
• @appium/types vs wd
• mockttp vs ts-mockito
• mock-socket vs ts-mockito
• rewire vs ng-mocks
• msw vs miragejs
• codeceptjs vs playwright-bdd
• codeceptjs vs nightwatch
• mocha vs jasmine-core
• mock-socket vs ng-mocks
• fast-check vs rewire
• ts-jest vs @golevelup/ts-jest