Amazon Pay ECE: add to block checkout

[annemirasol]

Objective
If Amazon Pay express checkout is enabled and supported, shoppers should be able to use Amazon Pay to complete a successful purchase via the block checkout page.

Acceptance criteria

When Amazon Pay express checkout is enabled and supported:

• Displays the payment button in the block checkout page.
• Displays the correct line items, shipping fee and total amount in the payment modal.
• Allows shoppers to complete the purchase using Amazon Pay. (Blocked by Amazon Pay ECE: support payment processing via confirmation tokens #3737)
• Displays in the Order Details page if Amazon Pay was used for the order. (Blocked by Amazon Pay ECE: support payment processing via confirmation tokens #3737)

When Amazon Pay express checkout is not enabled:

• Does not display the payment button in the block checkout page.

Others

• No regression for other pages, e.g. product, classic cart, classic checkout, pay-for-order etc.
• No regression for other express checkout methods.
• No regression for stores that are still on PRB.
• Relevant documentation have been added or updated.

Notes

• Partially blocked by Amazon Pay ECE: add to settings page #3724 and Amazon Pay ECE: support payment processing via confirmation tokens #3737
• From previous experience with other ECE payment methods, we expect that adding Amazon Pay to block checkout will add it to block cart, as well.
• paymentMethodCreation: manual is not supported for Amazon Pay [1], and confirmation tokens must be used, instead of manually creating payment methods [2, 3].
• To create an Amazon Pay Sandbox test buyer account, which you will need for testing and development:
  1. Go to https://docs.stripe.com/elements/express-checkout-element in an incognito browser, or while logged out of your real Amazon account.
  2. If you see the Amazon Pay payment button, click it and create an account.
  • https://developer.amazon.com/docs/amazon-pay-checkout/amazon-pay-sandbox-accounts.html (See option 2.)

Links

1. https://docs.stripe.com/js/elements_object/create_without_intent#stripe_elements_no_intent-options-paymentMethodCreation
2. https://docs.stripe.com/elements/express-checkout-element/accept-a-payment
3. https://docs.stripe.com/js/confirmation_tokens