Add `--invoke` flag to CLI options for config mode testing of actions

[austinvalle]

terraform-plugin-testing version

github.com/hashicorp/terraform-plugin-testing v1.13.3

Use cases

Currently, to test an action with Config mode, you can only do so with the lifecycle.action_trigger field. If there isn't a natural choice for a managed resource to add this to, you can use a terraform_data managed resource as a workaround (which is a null resource that does nothing but take up space in the graph 😆 ):

• https://developer.hashicorp.com/terraform/language/invoke-actions#trigger-an-action-when-applying-a-configuration
• local_command action using this pattern

Proposal

We should consider adding the CLI flag pass-throughs for invoking an action directly, to provide a more direct test:

• https://developer.hashicorp.com/terraform/language/invoke-actions#invoke-an-action-from-the-cli
• https://github.com/hashicorp/terraform-plugin-testing/blob/main/helper/resource/additional_cli_options.go

We already have a place to put CLI options in terraform-plugin-testing, but we'll need to update terraform-exec to accept the flag (if it hasn't been updated already):

• https://github.com/hashicorp/terraform-exec

References

• How to perform a test of a terraform action #557