Automating Terraform Testing: From Unit Tests to End-to-End Validation

Infrastructure as code (IaC) is powerful, but deploying untested changes can be risky. On Day 18 of my 30-Day Terraform Challenge, I focused on automating testing for Terraform code, covering unit tests, integration tests, and end-to-end tests, all tied together in a CI/CD pipeline. Unit Tests Unit tests are fast, cheap, and safe because they test your module plan only—no real resources are created. Each unit test ensures your resources are configured correctly, such as validating cluster names, instance types, and open ports. These tests catch configuration errors and bad variables before anything reaches production. Unit tests run on pull requests, giving developers fast feedback and confidence that changes won’t break the module. Integration Tests Integration tests deploy real infrastructure, assert behavior, then destroy everything. They check how modules interact with actual cloud resources, like verifying that the application load balancer responds correctly and that EC2 instance