Adding test cases to api/controller directory for getting coverage >60%

[nguptaopensds]

Issue/Feature Description: Right now, api/controller package has test coverage of 30.1%, we need to make it more than 60%. For that we need to add more test cases to the package.

Why this issue to fixed / feature is needed(give scenarios or use cases): Quality improvement is integral part of any project and to reach that we need to achieve test coverage of more than 60%

How to reproduce, in case of a bug:

Other Notes / Environment Information: (Please give the env information, log link or any useful information for this issue)

[nguptaopensds]

This issue is child issue for #1268

[kumarashit]

Raise PR for 6-7 test cases . ETA 26/05/2020