Good Eggs Test Helpers

Basic setup used for legacy Good Eggs tests, which are not fully using Jest as they should be.

⚠️ Jest is the blessed test runner, assertion library, and mock library for Good Eggs code.

Assertions

⚠️ New Good Eggs code must use Jest assertions. Consider refactoring existing code via https://github.com/skovhus/jest-codemods.

This library exports an expect function, which is an instance of chai, with a standard set of configured plugins:

• chai-as-promised
• dirty-chai
• sinon-chai
• chai-datetime

import {expect} from 'goodeggs-test-helpers';

describe('...', () => {
  it('...', () => {
    expect(true).to.be.true();
  });
});

Mocks

⚠️ New Good Eggs code must use Jest mocks. Consider refactoring existing code via https://github.com/skovhus/jest-codemods.

This library exports a few SinonJS mock helpers. Generally speaking, in a codebase that isn't using Jest mocks, you should be using these and not the sinon package directly.

useSinonSandbox()

Call this in a describe block to create a SinonJS sandbox (which is restored automatically after each test). It returns this sandbox.

import {expect, useSinonSandbox} from 'goodeggs-test-helpers';

describe('...', () => {
  const {sandbox} = useSinonSandbox();

  it('...', () => {
    const barStub = sandbox.stub(foo, 'bar');
    /* ... */
    expect(barStub).to.have.been.calledOnce();
  });
});

This function also returns a helper function stubLogger, which allows you to mock a logger object within this sandbox. Regardless of how many recursive .child() logger are created with this mock, the returned method mocks (info, warn, etc.) will work across all children.

import {expect, useSinonSandbox} from 'goodeggs-test-helpers';
import logger from '...';

describe('...', () => {
  const {stubLogger} = useSinonSandbox();

  it('...', () => {
    const {error} = stubLogger(logger);
    /* ... */
    expect(error).to.have.been.calledOnce();
  });
});

For convenience, and to avoid conflicting version of sinon in your codebase, this library exports most of sinon's TypeScript types:

import {
  SinonStub,
  SinonSpy,
  SinonFake,
  SinonMock,
  SinonFakeTimers,
  SinonSandbox,
  SinonStubbedInstance,
} from 'goodeggs-test-helpers';

It also exports a convenient utility type, which solves a common boilerplate problem:

import {MethodStub} from 'goodeggs-test-helpers';

describe('...', () => {
  let fooBarStub: MethodStub<typeof foo.bar>;
  beforeEach(() => {
    fooBarStub = sandbox.stub(foo, 'bar');
  });
});

Contributing

Please follow our Code of Conduct when contributing to this project.

yarn install
yarn test

Releasing

To release a new version of this module, use yarn to bump the version in package.json and create a git tag, then push. This will automatically get published to the NPM registry via CI.

yarn version --new-version=<major|minor|patch|premajor|preminor|prepatch>
git push --follow-tags

License

MIT