[REFACTOR]: [NMI] Remove Default Case Handling

[Sakilmostak]

📝 Feature Description

• We utilize match statements to make pivotal decisions, such as generating requests based on the payment method type and managing responses received from the connector.
• These conditions generally go hand in hand with enum variants.
• Default case is used because a match statement needs to be exhaustive i.e. every variant needs to be covered.
• So, if all the explicit cases are handled then default is used to handle the rest.
• Each connector have these match statements but many of them don’t provide reference to each variant in their default case, rather a _ is put to handle all the other cases.
• This approach carries a risk because developers may inadvertently overlook the need for explicit handling of the new cases.

🔨 Possible Implementation

• Instead of relying on a default match case _, developers should handle each and every variant explicitly.
• By doing so, if there are any changes in the future, they can readily assess the impact of their modifications simply by compiling the code.
• You can check this PR for further reference refactor(connector): [Zen] refactor Zen payment methods not implemented errors #1955

🔖 Note: All the changes needed should be contained within hyperswitch/crates/router/src/connector/

📦 Have you spent some time checking if this feature request has been raised before?

• I checked and didn't find a similar issue

📦 Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

✨ Are you willing to submit a PR?

[Cioraz]

Hey, Im interested in taking up this issue

[AkshayaFoiger]

Hey @Cioraz, sure! I've assigned this to you.

In case you have any queries, you can ask them on this issue thread, or on our discord server, or on slack whichever you are comfortable with

[Cioraz]

Just a follow up question,
The changes have to be made to line 120 in hyperswitch/crates/router/src/connector/nmi/transformer.rs in which I must match the errors for applepay and gpay.

And these the error changes for abandoned,cancelled,in_progress... fin lines 657

Am i right?

[AkshayaFoiger]

@Cioraz you are right! You have to make changes at line 120 and also line 115.
You have to match errors for all the unhandled variations of api_models::payments::WalletData and api::PaymentMethodData.

[Cioraz]

So Something like this would fix right?
Please correct me if im wrong as im still a beginner at rust

[AkshayaFoiger]

Hi @Cioraz,

You need to remove the default arm of the match statement and fill it with all possible values of WalletData. Your implementation is expected to be similar to

Here I have included a match arm for AliPayQr and AliPayRedirect. We expect you to fill all other match arms.
Note:To check for enum variants, do a command click on WalletData

Same implementation implies for line 120. Hope this answers you query.

[Cioraz]

Thanks a lot for the response will resolve it now

[srujanchikke]

Hey @Cioraz ,

We are glad you've raised a PR , May i know the reason why did you close the PR . We would be happy to help you out !

[Cioraz]

Sorry for the issue, i had forgotten to run cargo clippy to check so i just wanted to redo that, will soon raise another PR.

[Cioraz]

Could you help me with this when cargo building.

Below is the code

[srujanchikke]

Sorry for the issue, i had forgotten to run cargo clippy to check so i just wanted to redo that, will soon raise another PR.

You can reopen the same pr and push more commits with working code .
Coming to the issue you're facing , use a double colon instead: :: after errors in line 140 .