There doesn't seem to be a way to generate unit test coverage from a Terraform test. None of the current output options address coverage. As HCL isn't an executable language where lines of code are ...

│ with module.example_hub.module.avm_res_keyvault_vault.azurerm_key_vault.this, │ on .terraform/modules/example_hub.avm_res_keyvault_vault/main.tf line 7, in ...