jest SKILL.md skillA
jest from mindrally/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add mindrally/skills/jest@git:20261008.7682ca7Pins git:20261008.7682ca7 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- mindrally/skills
- Path
jest/SKILL.md- Versions recorded
- 2
- Latest version
- git:20261008.7682ca7, committed Oct 8, 2026
- First version recorded
- Jan 23, 2026
- Size
- 2,495 bytes
- Repository stars
- 278
- License
- Apache-2.0
Jest testing best practices for JavaScript and TypeScript applications, covering test structure, mocking, and assertion patterns.
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Jest Testing Best Practices You are an expert in JavaScript, TypeScript, and Jest testing. ## Core Principles ### Test Structure - Use descriptive test names that clearly explain expected behavior - Organize tests using `describe` blocks for logical grouping - Follow the Arrange-Act-Assert (AAA) pattern in each test - Keep tests focused on a single behavior or outcome ### Setup and Teardown - Use `beforeEach` and `afterEach` for test isolation - Use `beforeAll` and `afterAll` for expensive setup that can be shared - Clean up any side effects in teardown hooks ### Mocking - Use `jest.mock()` for module mocking - Use `jest.fn()` for function mocks - Use `jest.spyOn()` when you need to track calls but keep implementation - Clear mocks between tests with `jest.clearAllMocks()` - Avoid over-mocking: test real behavior when feasible ### Assertions - Use the most specific matcher available - Prefer `toEqual` for object comparison, `toBe` for primitives - Use `toMatchSnapshot` sparingly and with meaningful names - Include negative test cases (what should NOT happen) ### Async Testing - Always return promises or use async/await in async tests …
Read the whole file at its exact version.
How to install
mdr add mindrally/skills/jest@sha256:aac448009682f750The line at the top of this page pins the label git:20261008.7682ca7, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_kcx5mjodyvlcswcz)
1 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Jan 23, 2026 and Oct 8, 2026, about one every 258 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20261008.7682ca7 latest | 2026-10-08 | 7682ca7 | 2,495 B | A | view · diff |
| git:20260123.47f47c1 | 2026-01-23 | 47f47c1 | 2,415 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (2495 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
mindrally/skills · 278 stars · license Apache-2.0 · pushed 2026-10-08 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_kcx5mjodyvlcswcz GET https://markdownregistry.com/api/v1/resolve?ref=mindrally/skills/jest GET https://markdownregistry.com/api/v1/blob/aac448009682f7509b576349d2847ed40b6de65a7cb7afe50f531ae7b083a649
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.