# @beyondessential/eslint-config-jest

## Jest style guide as as shareable ESLint configuration

This package defines [Beyond Essential System](https://beyondessential.com.au/)'s style guide for Jest.

## Installation

Install the package and its required peer dependencies:

```sh
yarn add -D @beyondessential/eslint-config-jest eslint prettier
```

## Usage

You need to extend this package in your [ESLint configuration](https://eslint.org/docs/user-guide/configuring):

```json
{
  "extends": "@beyondessential/jest"
}
```

## Publishing

1. Checkout the latest code: `git fetch && git checkout master`
2. Commit your changes in a new branch
3. ⚠️ Don't forget to also update the package version: `npm version # < patch || minor || major >`
4. Create a pull request against `master`

After your PR is approved and merged:

```sh
git fetch && git checkout master && git pull
npm login
npm publish --access public
```

## Style guide

We use the recommended rules from [eslint-plugin-jest](https://www.npmjs.com/package/eslint-plugin-jest), with a few changes.

### Changes

| Rule                                                                                                               | Airbnb | BES                                                      | Comment                                                                                   |
| ------------------------------------------------------------------------------------------------------------------ | ------ | -------------------------------------------------------- | ----------------------------------------------------------------------------------------- |
| [jest/expect-expect](https://github.com/jest-community/eslint-plugin-jest/blob/HEAD/docs/rules/expect-expect.md)   | error  | ['warn', { assertFunctionNames: ['expect', 'assert*'] }] | Our `assert*` functions conventionally use `expect` under the hood                        |
| [jest/valid-describe](https://github.com/jest-community/eslint-plugin-jest/blob/HEAD/docs/rules/valid-describe.md) | error  | off                                                      | The implementation of this rule does not allow imported functions as `describe` callbacks |
| [jest/valid-title](https://github.com/jest-community/eslint-plugin-jest/blob/HEAD/docs/rules/valid-title.md)       | error  | off                                                      | Title may be a variable                                                                   |