checking a property's value against a regex when its actual value is null

[vrbcntrl]

Hi @eerkunt ,

I have an use case that I am testing i.e. SageMaker Notebook Instance not encrypted with KMS-CMK

my terraform plan json

"planned_values": {
		"root_module": {
			"resources": [
				{
					"address": "aws_sagemaker_notebook_instance.foo",
					"mode": "managed",
					"type": "aws_sagemaker_notebook_instance",
					"name": "foo",
					"provider_name": "aws",
					"schema_version": 0,
					"values": {
						"instance_type": "ml.t2.medium",
						"kms_key_id": null,
						"lifecycle_config_name": null,
						"name": "my-notebook-instance",
						"role_arn": "arn:aws:iam::123456789012:role/S3Access",
						"subnet_id": null,
						"tags": {
							"Name": "foo"
						}
					}
				}
			]
		}
	}

as you can see the kms_key_id property value is null in the plan

my test is that : The kms_key_id value must match the regex ".*kms.*" so I wrote the below BDD

Scenario: AWS SageMaker Notebook Instance not encrypted with KMS-CMK
        Given I have aws_sagemaker_notebook_instance defined
        Then it must contain kms_key_id
        And its value must match the ".*kms.*" regex

when I run the above BDD, all the 3 steps are PASSED even though the kms_key_id value is null in the plan....so not sure why the test is PASSED?

next, I changed the BDD to this

Scenario: AWS SageMaker Notebook Instance not encrypted with KMS-CMK
   Given I have aws_sagemaker_notebook_instance defined
   Then it must contain kms_key_id
   And its value must not be null
   Then its value must match the ".*kms.*" regex

and It failed at 3rd step as expected.

 Scenario: AWS SageMaker Notebook Instance not encrypted with KMS-CMK
        Given I have aws_sagemaker_notebook_instance defined
        Then it must contain kms_key_id
        And its value must not be null
          Failure: kms_key_id property in aws_sagemaker_notebook_instance.foo resource matches with Null/None regex. It is set to None.
        Then its value must match the ".*kms.*" regex

However, I observed one thing that if the property value is not null, then my first BDD works as expected. The behavior changes when the property value is null.

so, I am wondering what is the correct approach to test when the actual property in Terraform is null and we want to check the value against a regex/value?

the first BDD approach or the later?

[eerkunt]

Hello @vrbcntrl,

Thanks for reporting it 🎉

Both approach is valid, so both should work. Looks like you have found a bug.

[eerkunt]

Could you please have a try with 1.0.29 ?

[vrbcntrl]

Thanks @eerkunt for the quick turnaround.

Tested both my above BDDs and they work as expected with 1.0.29.

Thanks again, have a great day!

[eerkunt]

Thanks for the quick validation. 🎉

Closing the issue.