Simulate a paste event in Cypress

paste.js

/**
 * Simulates a paste event.
 *
 * @param pasteOptions Set of options for a simulated paste event.
 * @param pasteOptions.destinationSelector Selector representing the DOM element that the paste event should be dispatched to.
 * @param pasteOptions.pastePayload Simulated data that is on the clipboard.
 * @param pasteOptions.pasteFormat The format of the simulated paste payload. Default value is 'text'.
 */
function paste({ destinationSelector, pastePayload, pasteType = 'text' }) {
    // https://developer.mozilla.org/en-US/docs/Web/API/Element/paste_event
    cy.get(destinationSelector).then($destination => {
        const pasteEvent = Object.assign(new Event('paste', { bubbles: true, cancelable: true }), {
            clipboardData: {
                getData: (type = pasteType) => pastePayload,
            },
        });
        $destination[0].dispatchEvent(pasteEvent);
    });
}

Nice one @erwinvanlun!