测试优惠、优惠券和退订，而不只是注册。

const submitted = new Date();
await page.getByRole('button', { name: 'Get 20% off' }).click();

// Offers often take minutes: this waits up to 10.
const coupon = await qa.waitForCode(address, { type: 'coupon', since: submitted, timeout: 600 });
expect(coupon.discount).toBe('20% off');

await page.getByLabel('Promo code').fill(coupon.value);
await page.getByRole('button', { name: 'Apply' }).click();
const result = await qa.recordCouponResult(address, 'accepted', { oneTime: true });
expect(result.check?.status).toBe('pass');

// Unsubscribe as a person would, then watch for more marketing.
await page.goto(await qa.waitForLink(address, { type: 'unsubscribe', since: submitted }));
await qa.markUnsubscribed(address, { service: 'acme.com' });

from proxymail_qa import create_address, expect_no_email, now, wait_for_code


def sign_up_for_offer(page, email):
    page.goto("/offer")
    page.get_by_label("Email").fill(email)
    page.get_by_role("button", name="Get 20% off").click()


def test_welcome_offer_once_per_person(page):
    address = create_address()["address"]
    submitted = now()
    sign_up_for_offer(page, address)
    wait_for_code(address, since=submitted, type="coupon", timeout=600)

    # The same person as name+promo1@ (the same inbox): no second coupon.
    again = address.replace("@", "+promo1@")
    submitted = now()
    sign_up_for_offer(page, again)
    expect_no_email(again, since=submitted, type="code", subtype="coupon", timeout=300)