eslint-plugin-cypress

2.15.1 • Public • Published

Cypress ESLint Plugin CircleCI

An ESLint plugin for your Cypress tests.

Note: If you installed ESLint globally then you must also install eslint-plugin-cypress globally.

Installation

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

or

yarn add eslint-plugin-cypress --dev

Usage

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

{
  "plugins": [
    "cypress"
  ]
}

You can add rules:

{
  "rules": {
    "cypress/no-assigning-return-values": "error",
    "cypress/no-unnecessary-waiting": "error",
    "cypress/assertion-before-screenshot": "warn",
    "cypress/no-force": "warn",
    "cypress/no-async-tests": "error",
    "cypress/no-pause": "error"
  }
}

You can allow certain globals provided by Cypress:

{
  "env": {
    "cypress/globals": true
  }
}

Recommended configuration

Use the recommended configuration and you can forego configuring plugins, rules, and env individually. See below for which rules are included.

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

Disable rules

You can disable specific rules per file, for a portion of a file, or for a single line.

Disable the cypress/no-unnecessary-waiting rule for the entire file by placing this at the start of the file:

/* eslint-disable cypress/no-unnecessary-waiting */

Disable the cypress/no-unnecessary-waiting rule for only a portion of the file:

it('waits for a second', () => {
  ...
  /* eslint-disable cypress/no-unnecessary-waiting */
  cy.wait(1000)
  /* eslint-enable cypress/no-unnecessary-waiting */
  ...
})

Disable the cypress/no-unnecessary-waiting rule for a specific line:

it('waits for a second', () => {
  ...
  cy.wait(1000) // eslint-disable-line cypress/no-unnecessary-waiting
  ...
})

You can also disable a rule for the next line:

it('waits for a second', () => {
  ...
  // eslint-disable-next-line cypress/no-unnecessary-waiting
  cy.wait(1000)
  ...
})

For more, see the ESLint rules documentation.

Rules

These rules enforce some of the best practices recommended for using Cypress.

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
no-async-tests Prevent using async/await in Cypress test case
unsafe-to-chain-command Prevent chaining from unsafe to chain commands
no-force Disallow using force: true with action commands
assertion-before-screenshot Ensure screenshots are preceded by an assertion
require-data-selectors Only allow data-* attribute selectors (require-data-selectors)
no-pause Disallow cy.pause() parent command

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
  }
}

Or you can simply add its recommended config:

{
  "extends": ["plugin:chai-friendly/recommended"]
}

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

Use the following commit message conventions: https://github.com/semantic-release/semantic-release#commit-message-format

Dependents (478)

Package Sidebar

Install

npm i eslint-plugin-cypress

Weekly Downloads

2,669,038

Version

2.15.1

License

MIT

Unpacked Size

47.8 kB

Total Files

35

Last publish

Collaborators

  • chrisbreiding
  • cypress-npm-publisher
  • bahmutov