[Bug] ListTestCase interface exec failed.

*Description*:
The ListTestCase interface throws a 500 exception when a test resource yaml file other than the one created exists in the atest directory.


*Repro steps*:

1. git pull repo
2. go build -o atest main.go
3. ./atest server
4. access front page and new create test resource.
5. then click node.

>**Note**: If there are privacy concerns, sanitize the data prior to

caused by the presence of yaml files other than the test resource file in the atest executable directory.

Start by building and running the server as described with main.go and an extra YAML file in the atest executable directory. Reproduce the failure by creating a test resource and selecting its node, then trace the ListTestCase interface response. Done means the interface no longer returns a 500 when unrelated YAML files are present.

Written by the indexing model from the issue text.