Cypress automatically includes Bluebird and exposes it as Cypress.Promise.
Instantiate a new bluebird promise.
Syntax
new Cypress.Promise(fn)
Usage
Correct Usage
new Cypress.Promise((resolve, reject) => { ... })
Incorrect Usage
new cy.Promise(...) // Errors, cannot be chained off 'cy'
Examples
Use Cypress.Promise to create promises. Cypress is promise aware so if you return a promise from inside of commands like .then(), Cypress will not continue until those promises resolve.
Basic Promise
cy.get('button').then(($button) => {
return new Cypress.Promise((resolve, reject) => {
// do something custom here
})
})
Waiting for Promises
it('waits for promises to resolve', () => {
let waited = false
function waitOneSecond() {
// return a promise that resolves after 1 second
return new Cypress.Promise((resolve, reject) => {
setTimeout(() => {
// set waited to true
waited = true
// resolve with 'foo' string
resolve('foo')
}, 1000)
})
}
cy.wrap(null).then(() => {
// return a promise to cy.then() that
// is awaited until it resolves
return waitOneSecond().then((str) => {
expect(str).to.eq('foo')
expect(waited).to.be.true
})
})
})