vitest-4

What problem does it solve?

Vitest 4 testing patterns and best practices streamline test writing, organization, and reliability by providing consistent patterns for asserts, mocks, spies, and module mocking.

Core Features & Use Cases

• Establishes recommended test structure using AAA pattern and isolated tests.
• Demonstrates clear assertion strategies (toBe, toEqual, toStrictEqual, etc.) and appropriate use of mocks, spies, and vi.mock.
• Covers async testing, fake timers, parameterized tests, and snapshot/testing organization.
• Provides guidance on building robust tests for vitest in TypeScript projects with examples.

Quick Start

Write a Vitest test file following describe/it/test blocks with asserts; for example, import { describe, it, test, expect } from "vitest"; run tests via vitest to verify behavior.