HTMLFormElement.requestSubmit lacks browser support

[thekaveman]

In #1071 we introduced a programmatic reCAPTCHA challenge to ensure our HTML5 form validation was taking place.

In #1088 we added the spinner animation to certain buttons, and in doing so, worked through a problem introduced in #1071 where the Javascript .submit() on a form element wasn't triggering the submit event. The solution using .requestSubmit() does generate the submit event and it all worked as expected.

However some key browsers/versions don't yet support the .requestSubmit() method. Specifically, iPhone Safari until version 16, which was only released in September 2022.

More on caniuse.com

To Reproduce

Steps to reproduce the behavior:

1. Using an iPhone with Safari < 16.0 (e.g. 15.6), go to the dev site
2. Navigate to the Benefit selection screen
3. Choose an option, click "Choose this Benefit"
4. Form does not submit, see error in browser console:

Expected behavior

The form should submit on all browsers/devices.

Desktop (please complete the following information)

• Device: MacBook Pro
• Browser: Safari
• Version: 15.6

Smartphone (please complete the following information)

• Device: iPhone SE
• Browser: Safari
• Version: 15.6

[machikoyasuda]

Was able to reproduce on my MacBook Pro / Safari 15