[Payment Method Improvements] Cash Payment Improvements

[backwardstruck]

Closes: #11413

Description

This PR introduces a new "Change Due" calculator screen for merchants processing cash payments, enhancing the existing cash handling functionalities in our mobile app.

The new screen will only be visible when the 'OTHER_PAYMENT_METHODS' feature flag is enabled, ensuring that this functionality can be tested incrementally and does not impact users negatively during the roll-out phase.

Testing instructions

1. Turn on the 'OTHER_PAYMENT_METHODS' feature flag.
2. Navigate to the payment capture screen and select the cash payment option.
3. Verify that the "Change Due" calculator screen appears

The following will be in a subsequent PR for easier review:

• The "Cash Received" field displays the total amount due by default.
• The UI corresponds to the new design specifications and not the current iOS design.

• Edit the amount in the "Cash Received" field and ensure the displayed change due updates accordingly.
• Tap "Mark order as complete", and confirm that it functions similarly to the "Mark as paid" button in the current dialog.
• The new calculator will allow merchants to easily calculate the change owed to a customer when capturing a cash payment.
• Complete unit test(s)

Images/gif

Images or gifs demonstrating the new screen and comparisons to the previous version will be attached here.

• I have considered if this change warrants release notes and have added them to RELEASE-NOTES.txt if necessary. Use the "[Internal]" label for non-user-facing changes.

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce Android by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce Android
	Flavor	Jalapeno
	Build Type	Debug
	Commit	3a5645c
	Direct Download	woocommerce-prototype-build-pr11414-3a5645c.apk

[kidinov]

Conceptually everything looks correct to me 👍 I just left a few minor suggestions

[backwardstruck]

I added this unit test but I'm not sure there's much to test yet. Can I leave these TODO's for the next PR?

[soundsokay]

Yes. Fine to fix in the next PR. Think of it as test-driven development. You might even ticket that out: "Add implementation so order details load successfully emits success state test passes"

[backwardstruck]

I added it as a task on this ticket. I can easily convert to GH issue if it ends up being a separate PR from the other tasks.

[kidinov]

👋 @backwardstruck

Thanks @kidinov This should now be updated and ready for review. Not sure why I can't get it to pass CI 😢

There are tests that are failing. Click on "details" next to the failed job and look up what tests should be fixed

Overal looks good to me. I left a few comments. Please take a look

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 36.84211% with 24 lines in your changes are missing coverage. Please review.

Project coverage is 40.81%. Comparing base (00bd4c5) to head (81fe1fc).

Files	Patch %	Lines
...ts/methodselection/ChangeDueCalculatorViewModel.kt	0.00%	18 Missing ⚠️
...ts/methodselection/SelectPaymentMethodViewModel.kt	68.42%	4 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##              trunk   #11414      +/-   ##
============================================
- Coverage     40.83%   40.81%   -0.02%     
- Complexity     5180     5181       +1     
============================================
  Files          1070     1071       +1     
  Lines         62310    62335      +25     
  Branches       8499     8500       +1     
============================================
+ Hits          25444    25445       +1     
- Misses        34578    34602      +24     
  Partials       2288     2288              

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[backwardstruck]

@kidinov it looks like CI is passing now with those changes. Let me know if you have additional suggestions.

[kidinov]

LGTM

I left one NP comment regarding visibility of a method. Feel free to ignore it