I am implementing a Terraform provider using the Terraform Plugin Framewok.

I have an issue with a resource. Here is a dummy example :

resource "dummy_resource" "dummy" {
  category                 = "A"      // Can be A, B or C
  performance              = "high"   // Can be high, medium or low
}

The API to create a Dummy resource have 2 configurable fields, category and performance. In this API (that I can’t modify), there is the following rule :

• If category == A the given performance field will be ignored and performance will be set to high

Note : In my real use case, there is multiple rules that can change over time so I can’t know exactly what the rules will be.

The issue I have here is that, if a user uses the following configuration

resource "dummy_resource" "dummy" {
  category                 = "A"    
  performance              = "low" 
}

The API will not use the given performance field and set performance to high resulting in the following error :

Error: Provider produced inconsistent result after apply

        When applying changes to dummy_resource.dummy, provider
        "provider["registry.terraform.io/hashicorp/my_provider"]" produced an
        unexpected new value: .performance: was cty.StringVal("low"), but now
        cty.StringVal("high").

        This is a bug in the provider, which should be reported in the provider's own
        issue tracker.

In order to avoid this error, I would like to prevent Terraform from checking the performance field value as I can never be sure the API will use the given value.

Is it possible to do that? And how ?