kuceb / eslint-plugin-cypress

An ESLint plugin for projects that use Cypress

Cypress ESLint Plugin

An ESLint plugin for your Cypress tests.

Specifies globals for Cypress cy, Cypress, browser and mocha globals.

Installation

npm install eslint-plugin-cypress --save-dev

Usage

Add an .eslintrc.json file to your cypress directory with the following:

// my-project/cypress/.eslintrc.json

{
  "plugins": [
    "cypress"
  ],
  "env": {
    "cypress/globals": true
  }
}

Rules

These rules enforce some of the best practices recommended for using Cypress. Use them by adding the following to your eslint config:

// my-project/cypress/.eslintrc.json

{
  "extends": [
    "plugin:cypress/recommended"
  ]
}

Rules with a check mark (✅) are enabled by default while using the plugin:cypress/recommended config.

NOTE: These rules currently require eslint 5.0 or greater. If you would like support added for eslint 4.x, please 👍 this issue.

	Rule ID	Description
✅	no-assigning-return-values	Prevent assigning return values of cy calls
✅	no-unnecessary-waiting	Prevent waiting for arbitrary time periods
	assertion-before-screenshot	Ensure screenshots are preceded by an assertion

Chai and no-unused-expressions

Using an assertion such as expect(value).to.be.true can fail the ESLint rule no-unused-expressions even though it's not an error in this case. To fix this, you can install and use eslint-plugin-chai-friendly.

npm install --save-dev eslint-plugin-chai-friendly

In your .eslintrc.json:

{
  "plugins": [
    "cypress",
    "chai-friendly"
  ],
  "rules": {
    "no-unused-expressions": 0,
    "chai-friendly/no-unused-expressions": 2
  }
}

Contribution Guide

To add a new rule:

• Fork and clone this repository
• Generate a new rule (a yeoman generator is available)
• Run yarn start or npm start
• Write test scenarios then implement logic
• Describe the rule in the generated docs file
• Make sure all tests are passing
• Add the rule to this README
• Create a PR