Create custom command in Cypress containing asserting / chain commands

Question

I wish to create a custom command that contains status code assertions:

cy.wait('@interceptedEndpoint')
    .its('response.statusCode')
    .should('eq', 200)

the last two lines are what I want inside the custom command

.its('response.statusCode')
.should('eq', 200)

My initial idea is below which obviously wouldn't work

Cypress.commands.add('checkResponse', {prevSubject: 'element'}, () => {
    .its('response.statusCode')
    .should('eq', 200)
})

What am I missing above to make the custom command creation correct?

EDIT: In addition to Udo.Kier's answer. I needed to set prevSubject to true to make it accept the response for the expected assertion.

Answer 1

You can try adding the subject parameter,

Cypress.commands.add('checkResponse', {prevSubject: true}, (subject) => {
  cy.wrap(subject)
    .its('response.statusCode')
    .should('eq', 200)
})

...

cy.wait('@interceptedEndpoint').checkResponse()

Alternatively, with the wait inside the custom command:

Cypress.commandsCommands.add('waitAndCheckResponse', (subjectAlias) => {
  cy.wait(subjectAlias)
    .its('response.statusCode')
    .should('eq', 200);
})

...

cy.waitAndCheckResponse('@interceptedEndpoint')