Turn on cypress uncaught:exception after turning it off

Question

I'm currently trying to use Cypress for the first time and turn off cypress uncaught:exception during a certain test but I would like to turn it on once the test finished. How can I do that ? Thanks

PS: I disable it this way `

cy.on('uncaught:exception', () => false);

Answer 1

As well as cy.on() you can use cy.once() which turns off after the first catch.

Or there is cy.off().

Some examples from Cypress own code:

cy.once('fail', (err) => {
  expect(err.message).to.match(/^A callback was provided ... /)
    .and.match(/ESOCKETTIMEDOUT|ETIMEDOUT/)
  done()
})

cy.on('log:added', handleAddLog)
cy.on('fail', (err) => {
  cy.off('log:added', handleAddLog)
})

const onNavChanged = (event) => {
  if (event === 'page navigation event (load)') {
    cy.off('navigation:changed', onNavChanged)
    cb()
  }
}

cy.on('navigation:changed', onNavChanged)

---

Named handler

Note the "named" function used for the handler - this is so that same listener is turned off (you can have multiple listeners, and turn them off individually).

So in your code

const noError = () => false;
cy.on('uncaught:exception', noError);
...  // later
cy.off('uncaught:exception', noError);

---

Type definitions

namespace CypressOnceTests {
  Cypress.once('uncaught:exception', (error, runnable) => {
    error // $ExpectType Error
    runnable // $ExpectType Runnable
  })

  cy.once('uncaught:exception', (error, runnable) => {
    error // $ExpectType Error
    runnable // $ExpectType Runnable
  })
}

namespace CypressOffTests {
  Cypress.off('uncaught:exception', (error, runnable) => {
    error // $ExpectType Error
    runnable // $ExpectType Runnable
  })

  cy.off('uncaught:exception', (error, runnable) => {
    error // $ExpectType Error
    runnable // $ExpectType Runnable
  })
}