feat(product-sync): on product variant actions, use SKU as the first option instead of variantId.

[ahmetoz]

Summary:

Pr is changing the product variant actions, now it's using SKU as the first option for variant update actions:

for example setAttribute action documentation explains it : variantId - Number or sku - String - Required

Why we needed it?

We have lots of these kinds of errors: A staged variant with variantId '3' does not exist... I checked one of the product and it indeed doesn’t have that variant. I also checked the history of that product in master because I thought that the product could have before 3 variants and then one got removed. But it always has 2 variants. So it’s weird that we try to update with variant 3 when this variant never existed.

It might not resolve the issue for us but could help with finding the reason.

Error message from the API:

{
      action: {
       action: "setAttribute"        
       name: "attributeName"        
       staged: true        
       value: [
        0: "AU:0"         
        1: "DE:0"         
        2: "FR:0"         
        3: "NL:0"         
        4: "NZ:0"         
       ]
       variantId: 3        
      }
      actionIndex: 7       
      code: "InvalidOperation"       
      message: "A staged variant with variantId '3' does not exist."       
}

Review Note: I did not add additional tests for the case, currently the cases already covered, so I just updated the existing ones.

[coveralls]

Coverage increased (+0.06%) to 97.725% when pulling e8462920f582e80ee06a138b90d91c59762a80f7 on use-sku-as-first-option-for-attribute-update-actions into ae2272485b9a4c25ba8d433ad2e02dedb8dd72f5 on master.

[ahmetoz]

@VineetKumarKushwaha 🙏 thanks for the review. could we release it?