[Community Skill] Jest

[Mane087]

Community Skill Submission

Skill Name

Jest

Description

Project-agnostic Jest patterns for modern TypeScript/JavaScript testing. Covers:

• Test structure (Arrange/Act/Assert, describe/it conventions)
• Matchers and expect best practices
• Async testing (Promises, async/await, rejects, assertion counts)
• Setup/teardown and test isolation
• Mocking strategy (boundary-first, spies vs module mocks)
• Mock functions API (jest.fn, call assertions)
• Manual mocks (mocks) and class mocks
• Timer mocks (fake timers, advancing time)
• Snapshot testing (responsible usage and maintenance)
• Platform/environment configuration (node vs jsdom)
• Coverage practices and CI-friendly runs

Why This Skill?

Jest is widely used across frontend, backend, and shared libraries. This skill helps AI assistants produce deterministic, maintainable, low-flake tests and choose correct mocking/testing patterns without over-mocking or introducing brittle snapshots.

Checklist

• [ x ] Skill is in the community/ folder
• [ x ] Includes SKILL.md with proper structure
• [ x ] Has clear trigger conditions
• [ x ] Includes at least 3 code examples
• [ x ] Lists anti-patterns to avoid
• [ x ] Tested with Claude Code or OpenCode
• [ x ] Not a duplicate of existing skills

Framework/Library Version

Jest 29+ (recommended baseline; works with modern TS/ESM setups)

Testing

Validated patterns across multiple TS/JS codebases:

• Node services and libraries (testEnvironment: node)
• Frontend utilities (testEnvironment: jsdom)
• Async-heavy modules (Promise flows, error handling)
• Time-based logic (debounce/throttle/polling using fake timers)
• Snapshot usage limited to stable serialized outputs

Notes: This submission is project-agnostic and focuses on reusable patterns. Repo-specific conventions (ts-jest vs babel-jest, ESM vs CJS) should be added as references/ in downstream skills.

---

Voting

Community members: Please vote using reactions!

• Approve - Use any positive reaction (thumbs up, heart, rocket, etc.)
• Reject - Use thumbs down reaction

Voting period: 7 days from PR creation.

[Alan-TheGentleman]

Review Summary

Hey @Mane087! Great Jest skill submission. Here's what needs to be fixed for CI to pass:

1. Frontmatter Format Issue

The frontmatter has a formatting problem - there's an extra line with dashes at the end that shouldn't be there:

---

name: jest
description: >
...
allowed-tools: Read, Edit, Write, Glob, Grep, Bash, WebFetch, WebSearch, Task
-----------------------------------------------------------------------------   # ← Remove this line

Should be:

---
name: jest
description: >
  Jest testing patterns and best practices for modern TypeScript/JavaScript projects.
  Trigger: Writing, refactoring, or reviewing Jest unit/integration tests.
metadata:
  author: gentleman-programming
  version: "1.0"
---

2. Remove Extra Fields

Remove these non-standard fields from frontmatter:

• license
• allowed-tools

What's Good

• Excellent content coverage (matchers, async, mocks, timers, snapshots)
• Great code examples
• Proper conventional commit format

Once you fix the frontmatter, CI should pass. Thanks for contributing!

[Mane087]

Ok, I got it. I'm gonna apply those suggestions

[github-actions]

🗳️ Community Skill Voting

Thank you for submitting jest!

How to Vote

Community members, please vote using reactions on this PR:

Vote	Reaction
✅ Approve	👍 👏 🎉 🚀 ❤️ (any positive)
❌ Reject	👎

Voting Period

Ends: Saturday, January 31, 2026 (7 days from now)

Acceptance Criteria

• Minimum 3 total votes required
• More positive votes than negative votes
• Skill follows the contribution guidelines

---

This comment was automatically generated. Maintainers may fast-track exceptional contributions.

[github-actions]

⏰ Voting Period Ended

Unfortunately, this PR did not receive the minimum required votes (3).

Results: +0 / -0 (0 total votes)

The PR will remain open for another week. Please help spread the word!

If no votes are received in the extended period, this PR may be closed.