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explore / Web & frontend / mozg / Vitest

Vitest · Guide

Answer questions from the Vitest guide: writing and running tests, mocking functions, modules and timers with vi, snapshot testing, coverage, browser mode, workspaces, test context and the CLI commands with their flags.

1,607 notes · updated 2026-08-15 · trained 84%

since last sitting: +52 newly passed — this brain is learning · the verified changelog →

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https://mozg.sh/mcp --header "Authorization: Bearer …"
> use mozg/vitest-guide — …
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Ask it things like

answers 51/60 on its latest exam · anti-bluff 1/1
What are the three browser providers available in Vitest?Browser Mode✓
What are the main Vitest hooks and what is their execution order in a describe block?Hooks & Setup/Teardown✓
What is the correct way to mock an async function in Vitest?Mocking Functions & Modules✓
How do you write a basic test in Vitest and what function does it start with?Writing Tests & Running✓
How do you enable browser mode in Vitest configuration?Browser Mode✓
What does the maxConcurrency flag control?Concurrency & Parallelization✓
What are the two coverage providers available in Vitest?Coverage & Reporting✓
Where must vi.mock, vi.unmock, and vi.hoisted be placed in a test file?Mocking Functions & Modules✓

What it can answer

60 coverage checks
84%
Answers 52 of the exam's 61 questionsIt answers 52 questions, 52 more than last time, out of an exam that grew by 61.Nothing it used to answer has stopped working.
✓Snapshot Testing6 / 6
▲Browser Mode5 / 7
▲CLI Commands & Flags5 / 6
✓Concurrency & Parallelization5 / 5
▲Mocking Functions & Modules5 / 6
▲Writing Tests & Running5 / 6
✓Coverage & Reporting4 / 4
✓Hooks & Setup/Teardown4 / 4
▲Benchmarking3 / 5
▲Test Context & Advanced3 / 5
✓Timers & Fake Time3 / 3
✓Workspaces & Projects3 / 3
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Attacks survived

re-run weekly · 2026-08-09
✓gate-battery12/12 known hostile payloads caught by the ingest gate
✓injection-corpusevery active note scanned — no steering language
✓secret-corpusevery active note scanned — no keys or credentials

heuristic scans against known attack classes — measured and dated, not a promise of unpoisonability

Inside

  • TestProject.vite property · advanced/projects
  • TestProject.isRootProject() method · advanced/projects
  • TestProject.serializedConfig property · advanced/projects
  • TestProject.hash property · advanced/projects
  • TestProject.provide() method · test context & advanced
  • TestProject.createSpecification() method · advanced/projects
  • TestProject name resolution · advanced/projects
  • TestProject.vitest property · advanced/projects
  • TestProject.globalConfig property · advanced/projects
  • TestProject.config property · advanced/projects
  • TestProject.sharedViteServer property · advanced/projects
  • TestProject.browser property · browser/configuration
  • TestProject.getProvidedContext() method · test context & advanced
  • TestProject.globTestFiles() method · advanced/projects

Licence

CC BY-NC-SA 4.0

Use it, copy it, build on it, with credit. Selling it is not allowed.