Can't create more than one product variant without option group

[munxar]

Describe the bug
When I try to create a product variant manually, only the first variant can be created. After this an error is displayed that that (name of the first variant) allredy exists.

To Reproduce
Steps to reproduce the behavior:

1. install vendure, without seed data
2. login to /admin backend
3. create a product
4. go to manage variants
5. define no option group
6. add a product variant e.g. name: var1 sku: 100 (success)
7. add another product variant e.g. name: var2 sku:101 (error)
   frontend error: A ProductVariant with the selected options already exists: var1
   backend error: USER_INPUT_ERROR: error.product-variant-options-combination-already-exists

Expected behavior
No error, var2 should be created.

Environment (please complete the following information):

• @vendure/core 2.0.0:
• Nodejs version 16.17.1
• Database (mysql/postgres etc): postgres 14.7

[habibullahturkmen]

I'm having the same issue when creating a variant without an option group (Vendure v2).

[michaelbromley]

Hi, thanks for the report. This is more of a UX issue - the UI is not clearly communicating the constraints here:

• ProductVariants are based on ProductOption combinations.
• So if a Product has no OptionGroups defined, it by definition can only have a single variant.
• The correct flow for adding more variants would be:
  1. Add a product option group
  2. Add two or more options to the group
  3. Create the variant(s) desired based on the available options.

I'll see how I can make this more clear in the UI.

[arjunmurali1993]

Hi, thanks for the report. This is more of a UX issue - the UI is not clearly communicating the constraints here:

• ProductVariants are based on ProductOption combinations.

• So if a Product has no OptionGroups defined, it by definition can only have a single variant.

• The correct flow for adding more variants would be:

  1. Add a product option group
  2. Add two or more options to the group
  3. Create the variant(s) desired based on the available options.

I'll see how I can make this more clear in the UI.

Quick question regarding the above @michaelbromley .

Do we need to create ProductOptionGroups and corresponding ProductOptions for each separate Product before we can create the required ProductVariants for that Product?

For example, if I create colours ProductOptionGroup with values Black, Red for product T Shirt 1, can I not reuse the same for another product T Shirt 2? Or is this not possible?