test(core): TRAC-281 replace flaky add-to-cart toast assertions in cart and coupon E2E tests

The add-to-cart success message renders as a Sonner toast that
auto-dismisses after ~4s, so asserting on it is inherently racy. The
existing `toPass` retry in `cart.spec.ts` was also logically broken:
the catch branch reloaded the page, which destroys client-side toast
state, so retries could never succeed once the first attempt missed
the toast.

Drop the toast assertion in both tests and wait on `networkidle`
after the add-to-cart click. The cart-page assertions on `/cart`
remain as the actual verification.

Additionally, rework the coupon-apply flake handling in
`coupon.spec.ts`. The previous catch/reload pattern only recovered if
the server had already applied the coupon (CATALYST-1685). When the
action silently failed, the reload alone could not bring the coupon
back. Replace it with a `toPass` retry that re-applies the coupon
from a clean reloaded state if the optimistic update reverts.

Refs TRAC-281
Refs CATALYST-1685
Co-Authored-By: Claude <noreply@anthropic.com>

Author: chanceaclark

core/tests/ui/e2e/cart.spec.ts

@@ -20,21 +20,9 @@ test('Cart page displays line item', async ({ page, catalog, currency }) => {
 
   await page.goto(product.path);
   await page.getByRole('button', { name: t('Product.ProductDetails.Submit.addToCart') }).click();
-
-  // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
-  const addToCartSuccessMessage = t.rich('Product.ProductDetails.successMessage', {
-    cartItems: 1,
-    cartLink: (chunks: React.ReactNode) => chunks,
-  }) as string;
-
-  await expect(async () => {
-    try {
-      await expect(page.getByText(addToCartSuccessMessage)).toBeVisible();
-    } catch {
-      await page.reload();
-      await expect(page.getByText(addToCartSuccessMessage)).toBeVisible();
-    }
-  }).toPass({ timeout: 30000, intervals: [2000] });
+  // The success toast auto-dismisses after ~4s, so asserting on it is racy.
+  // Wait for the add-to-cart action to settle and verify state via the /cart page instead.
+  await page.waitForLoadState('networkidle');
 
   await page.goto('/cart');
 

core/tests/ui/e2e/coupon.spec.ts

@@ -8,42 +8,42 @@ test('Valid coupon code can be applied to the cart', async ({ page, catalog, pro
 
   await page.goto(product.path);
   await page.getByRole('button', { name: t('Product.ProductDetails.Submit.addToCart') }).click();
+  // The success toast auto-dismisses, so wait for the add-to-cart action to settle
+  // and verify state on the /cart page.
+  await page.waitForLoadState('networkidle');
 
-  // eslint-disable-next-line @typescript-eslint/consistent-type-assertions
-  const addToCartSuccessMessage = t.rich('Product.ProductDetails.successMessage', {
-    cartItems: 1,
-    cartLink: (chunks: React.ReactNode) => chunks,
-  }) as string;
-
-  await expect(page.getByText(addToCartSuccessMessage)).toBeVisible();
   await page.goto('/cart');
-
   await expect(page.getByRole('heading', { name: t('Cart.title') })).toBeVisible();
 
-  await page.getByLabel(t('Cart.CheckoutSummary.CouponCode.couponCode')).fill(coupon.code);
-  await page.getByRole('button', { name: t('Cart.CheckoutSummary.CouponCode.apply') }).click();
-  await page.waitForLoadState('networkidle');
+  // TODO: Remove retry pattern when root cause of next state issue is found/resolved [CATALYST-1685]
+  // The apply button can get stuck spinning, and the optimistic update reverts if the
+  // server action never completes. Retry from a clean reloaded state until the coupon
+  // sticks or the timeout is hit.
+  await expect(async () => {
+    if (
+      await page
+        .getByText(coupon.code)
+        .isVisible()
+        .catch(() => false)
+    ) {
+      return;
+    }
+
+    const couponInput = page.getByLabel(t('Cart.CheckoutSummary.CouponCode.couponCode'));
+
+    if (!(await couponInput.isVisible().catch(() => false))) {
+      await page.reload();
+    }
+
+    await couponInput.fill(coupon.code);
+    await page.getByRole('button', { name: t('Cart.CheckoutSummary.CouponCode.apply') }).click();
+    await page.waitForLoadState('networkidle');
 
-  try {
-    await expect(page.getByText(coupon.code)).toBeVisible();
-    await expect(
-      page.getByRole('button', { name: t('Cart.CheckoutSummary.CouponCode.removeCouponCode') }),
-    ).toBeVisible();
-  } catch {
-    // TODO: Remove try/catch when root cause of next state issue is found/resolved [CATALYST-1685]
-    // NextJS seems to have some issues when running local builds.
-    // In this test, the coupon button will get stuck spinning forever and cause the assertions to fail.
-    // This doesn't happen on deployed production builds, just local next builds.
-    // To combat this, if the previous assertions fail, we hard refresh the page and then try again.
-    await page.reload();
     await expect(page.getByText(coupon.code)).toBeVisible();
     await expect(
       page.getByRole('button', { name: t('Cart.CheckoutSummary.CouponCode.removeCouponCode') }),
     ).toBeVisible();
-
-    // eslint-disable-next-line no-console
-    console.warn('Coupon applied but page got stuck in loading state.');
-  }
+  }).toPass({ timeout: 60000, intervals: [3000] });
 });
 
 test('Invalid coupon code cannot be applied', async ({ page, catalog }) => {