Mocha skill

Skill Pyfagorass/bookofspells/skills/lambdatest/mocha-skill

Generates Mocha tests in JavaScript with Chai assertions and Sinon mocking. Use when user mentions "Mocha", "Chai", "sinon", "describe/it (not Jest)". Triggers on: "Mocha", "Chai", "sinon", "mocha test".From its SKILL.md

Install

npx -y skills add Pyfagorass/bookofspells --skill mocha-skill

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

2 things to look at

no licenseNo license file was found in the repository. Code published without one is not open source by default, so using it at work is a question for whoever answers licensing questions where you are.
2 stars2 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.

What its file declares

Copied from the file, not written here

The file declares its own license as MIT. That is the author’s claim about this one file, and it is not the same thing as the license GitHub reports for the repository, which is listed with the other numbers below.

SKILL.md

3.0 KB, 723 tokens by cl100k_base, as published. Nobody here has run it

Mocha Testing Skill

Core Patterns

Basic Test with Chai

const { expect } = require('chai');

describe('Calculator', () => {
  let calc;
  beforeEach(() => { calc = new Calculator(); });

  it('should add two numbers', () => {
    expect(calc.add(2, 3)).to.equal(5);
  });

  it('should throw on divide by zero', () => {
    expect(() => calc.divide(10, 0)).to.throw('Division by zero');
  });
});

Chai Assertions

expect(value).to.equal(5);
expect(arr).to.have.lengthOf(3);
expect(obj).to.have.property('name');
expect(str).to.include('hello');
expect(fn).to.throw(Error);
expect(arr).to.deep.equal([1, 2, 3]);
expect(obj).to.deep.include({ name: 'Alice' });

Sinon Mocking

const sinon = require('sinon');

describe('UserService', () => {
  let sandbox;
  beforeEach(() => { sandbox = sinon.createSandbox(); });
  afterEach(() => { sandbox.restore(); });

  it('fetches user from API', async () => {
    const stub = sandbox.stub(api, 'get').resolves({ name: 'Alice' });
    const user = await userService.getUser(1);
    expect(user.name).to.equal('Alice');
    expect(stub.calledOnce).to.be.true;
  });
});

Async Testing

it('should fetch data', async () => {
  const data = await fetchData();
  expect(data).to.have.property('id');
});

it('callback style', (done) => {
  fetchData((err, data) => {
    expect(err).to.be.null;
    done();
  });
});

Anti-Patterns

Bad	Good	Why
Missing `done()`	Use async/await	Hanging tests
No sandbox	`sinon.createSandbox()`	Stubs leak
Arrow in `describe`	Regular function for `this.timeout()`	Context

Quick Reference

Task	Command
Run all	`npx mocha`
Watch	`npx mocha --watch`
Grep	`npx mocha --grep "login"`
Timeout	`npx mocha --timeout 10000`
Recursive	`npx mocha --recursive`

Setup: `npm install mocha chai sinon --save-dev`

Deep Patterns → `reference/playbook.md`

§	Section	Lines
1	Production Configuration	mocharc, NYC coverage, TypeScript
2	Testing with Chai + Sinon	Stubs, spies, assertions
3	Advanced Sinon Patterns	Fake timers, nock HTTP, sequential
4	Async Patterns	Promise, await, callback, events
5	Hooks & Test Organization	Lifecycle, nesting, grep tags
6	Custom Reporters & Plugins	Reporter class, root hooks
7	Express/API Testing	Supertest integration
8	CI/CD Integration	GitHub Actions, services
9	Debugging Quick-Reference	10 common problems
10	Best Practices Checklist	13 items

What ships with it: 2 files

16.6 KB alongside SKILL.md

reference/

advanced-patterns.md4.9 KB
playbook.md11.7 KB