feat(rest): endpoint to merge vendor.

[rudra-superrr]

Closes: #2869

Description: this new endpoint will merge the source vendor to the target vendor.

[rudra-superrr]

Made the changes.

[rudra-superrr]

Made the changes.

[bibhuti230185]

The current implementation of the mergeVendors method in the VendorController class is not ideal because it mixes request parameters and request body in a PATCH request. A better approach would be to encapsulate all the required data in a single request body object. This makes the API cleaner and easier to use.
Here is a suggested approach:
Create a new class MergeVendorsRequest to encapsulate the request data.
Modify the mergeVendors method to accept this new class as the request body.

Test Findings:
Below 2 snarios to be looked up

1. Merge fails if request body is not given. Is this ideal case? Or the request Body is required only if we need to modify the data other than the merged content
2. Empty/null parameter throws 500 Internal error

Attached are the screenshot of API test through rest client

[rudra-superrr]

Hi @bibhuti230185 ,
Regarding the testing: yes, both the parameters and request body are mandatory in order to merge the vendor. In the second ss, it's showing error as the field(shortname) entered by you does not matches the field(shortName) present in the database.

In SW360, mixing request parameters and the request body in a PATCH request is generally acceptable. Since PATCH is intended for partial updates, it makes sense to send some parameters in the query string while including others in the request body. Additionally, we are not exposing any actual fields being updated—only the IDs, which is acceptable.

[GMishx]

Minor documentation changes needed. Rest looks good.

[GMishx]

Please use actual message if possible.

Suggested change

	value = "{\"message\": \"Merge failed.\"}"
	value = "{\"message\": \"Vendor used as source or target has an open MR\"}"

[GMishx]

409 conflict is not returned by this method as far as I can see. Instead there is a 500 undocumented with message Internal server error while merging the vendors.

Maybe you meant with the RequestStatus.IN_USE scenario which will currently throw 400 BAD REQUEST due to HttpMessageNotReadableException

[GMishx]

The current implementation of the mergeVendors method in the VendorController class is not ideal because it mixes request parameters and request body in a PATCH request. A better approach would be to encapsulate all the required data in a single request body object. This makes the API cleaner and easier to use. Here is a suggested approach: Create a new class MergeVendorsRequest to encapsulate the request data. Modify the mergeVendors method to accept this new class as the request body.

The idea is good @bibhuti230185 and @rudra-superrr , however given the current situation of other endpoints the current implementation would suffice. We can work on simplifying the entire API when we have good documentation and the current state complete. And maybe even release v3 of the API with it.

[rudra-superrr]

Hi @GMishx , made the changes as requested.