cypress-map

cypress-map

Extra Cypress query commands for v12+

• 📺 Watch the video Cypress v12 Querying Commands Introduction
• 📝 Read the blog post Cypress V12 Is A Big Deal
• 🎓 Covered in my course Cypress Plugins

Install

Add this package as a dev dependency

$ npm i -D cypress-map
# or using Yarn
$ yarn add -D cypress-map

Include this package in your spec or support file to use all custom query commands

import 'cypress-map'

Alternative: import only the query commands you need:

import 'cypress-map/commands/map'
import 'cypress-map/commands/tap'
// and so on, see the /commands folder

API

apply

const double = (n) => n * 2
cy.wrap(100).apply(double).should('equal', 200)

map

cy.get('.matching')
  .map('innerText')
  .should('deep.equal', ['first', 'third', 'fourth'])

mapInvoke

cy.get('#items li')
  .find('.price')
  .map('innerText')
  .mapInvoke('replace', '$', '')
  .mapInvoke('trim')

reduce

cy.get('#items li')
  .find('.price')
  .map('innerText')
  .mapInvoke('replace', '$', '')
  .map(parseFloat)
  .reduce((max, n) => (n > max ? n : max))
// yields the highest price

You can provide the initial accumulator value

cy.wrap([1, 2, 3])
  .reduce((sum, n) => sum + n, 10)
  .should('equal', 16)

See reduce.cy.js

tap

cy.get('#items li')
  .find('.price')
  .map('innerText')
  .tap() // console.log by default
  .mapInvoke('replace', '$', '')
  .mapInvoke('trim')
  // console.info with extra label
  .tap(console.info, 'trimmed strings')

Notice: if the label is provided, the callback function is called with label and the subject.

print

A better cy.log: yields the value, intelligently stringifies values using % and string-format notation.

cy.wrap(42)
  .print() // "42"
  // and yields the value
  .should('equal', 42)
// pass formatting string
cy.wrap(42).print('the answer is %d') // "the answer is 42"
cy.wrap({ name: 'Joe' }).print('person %o') // 'person {"name":"Joe"}'
// use {0} with dot notation, supported deep properties
// https://github.com/davidchambers/string-format
cy.wrap({ name: 'Joe' }).print('person name {0.name}') // "person name Joe"
// print the length of an array
cy.wrap(arr).print('array length {0.length}') // "array length ..."
// pass your own function to return formatted string
cy.wrap(arr).print((a) => `array with ${a.length} items`)
// if you return a non-string, it will attempt to JSON.stringify it
cy.wrap(arr).print((list) => list[2]) // JSON.stringify(arr[2])

See print.cy.js for more examples

primo

cy.get('.matching')
  .map('innerText')
  .primo()
  .invoke('toUpperCase')
  .should('equal', 'FIRST')

See primo.cy.js

prop

Works like cy.its for objects, but gets the property for jQuery objects, which cy.its does not

cy.get('#items li.matching').last().prop('ariaLabel').should('equal', 'four')

See prop.cy.js

at

Returns a DOM element from jQuery object at position k. Returns an item from array at position k. For negative index, counts the items from the end.

cy.get('#items li').at(-1).its('innerText').should('equal', 'fifth')

See at.cy.js

cy.invoke vs cy.map vs cy.mapInvoke

Here are a few examples to clarify the different between the cy.invoke, cy.map, and cy.mapInvoke query commands, see diff.cy.js

const list = ['apples', 'plums', 'bananas']

// cy.invoke
cy.wrap(list)
  // calls ".sort()" on the list
  .invoke('sort')
  .should('deep.equal', ['apples', 'bananas', 'plums'])

// cy.mapInvoke
cy.wrap(list)
  // calls ".toUpperCase()" on every string in the list
  .mapInvoke('toUpperCase')
  .should('deep.equal', ['APPLES', 'PLUMS', 'BANANAS'])

// cy.map
const reverse = (s) => s.split('').reverse().join('')
cy.wrap(list)
  // reverses each string in the list
  .map(reverse)
  .should('deep.equal', ['selppa', 'smulp', 'sananab'])
  // grabs the "length" property from each string
  .map('length')
  .should('deep.equal', [6, 5, 7])

See also

• cypress-should-really has similar functional helpers for constructing the should(callback) function on the fly.

Small print

Author: Gleb Bahmutov <[e-mail]> © 2022

• @bahmutov
• glebbahmutov.com
• blog
• videos
• presentations
• cypress.tips
• Cypress Tips & Tricks Newsletter
• my Cypress courses

License: MIT - do anything with the code, but don't blame me if it does not work.

Support: if you find any problems with this module, email / tweet / open issue on Github