This directory contains the test cases for the equivalence testing. The Terraform equivalence tests are E2E tests that are used to verify that the output of Terraform commands doesn't change in unexpected ways. The tests are run by comparing the output of the Terraform commands before and after a change to the codebase.

The equivalence tests are executed by the Terraform equivalence testing framework. This is built in github.com/hashicorp/terraform-equivalence-testing.

To execute the tests you must download the terraform-equivalence-testing binary and execute either the diff or update command. The diff command will run the tests and output the differences between the current and previous run. The update command will run the tests and update the reference output files.

You can also execute the tests directly using the equivalence-tests-manual GitHub action. This action will run the tests against a given branch and open a PR with the results.

The equivalence tests are run automatically by the Terraform CI system. The tests are run when every pull request is opened and when every pull request is closed.

When pull requests are opened, the tests run the diff command and will comment on the PR with the results. PR authors should validate any changes to the output files and make sure that the changes are expected.

When pull requests are closed, the tests run the update command and open a new PR with the updated reference output files. PR authors should review the changes and make sure that the changes are expected before merging the automated PR.

If the framework detects no changes, the process should be invisible to the PR author. No comments will be made on the PR and no new PRs will be opened.

New tests should be written into the tests directory. Each test should be written in a separate directory and should follow the guidelines in the equivalence testing framework documentation. Any tests added to this directory will be picked up the CI system and run automatically.