JAVASCRIPT

click element if it is visible in cypress

cy.get('body').then(($body) => {
    if ($body.find(selector).length > 0) {
        //element exists do something
    }
})

click element if it is visible in cypress

cy.get("selector_for_your_button").then($button => {
  if ($button.is(':visible')){
    //you get here only if button is visible
  }
})

cypress check if an element is visible

cy.get('section').should('have.class', 'container')