make testacc
Run first the testacc suite.
Then you can visualize the profile in html format:
go tool cover -html=profile.cov
The codecoverage can give you more usefull infos about were you could write a new tests for improving our testacc.
Feel free to read more about this on : https://blog.golang.org/cover.
https://www.terraform.io/docs/plugins/provider.html
Take a look at Terraform's docs about writing acceptance tests.
We try to keep easy issues for new contributors with label : https://github.com/dmacvicar/terraform-provider-libvirt/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22.
Feel free to pick also other issues