Test comment_service.dart

[palisadoes]

• Please coordinate issue assignment and PR reviews with the contributors listed in this issue Student Internship Programs #359

The Talawa code base needs to be 100% reliable. This means we need to have 100% test code coverage.

Tests need to be written for file:

lib/services/comment_service.dart

• When complete, all methods, classes and/or functions in the file will need to be tested.
• Our test/ folder has the same structure as the lib folder. Place your test file in the equivalent folder under test/. You may need to create the appropriate directory structure to do this.
• Current test code coverage for this file can be found here

IMPORTANT:

Please refer to this issue on how to implement these tests correctly:

• Complete Code Coverage for Views #1217

PR Acceptance Criteria

• When complete this file must show 100% coverage when merged into the code base. This will be clearly visible when you submit your PR.
• The PR will show a report for the code coverage for the file you have added. You can use that as a guide.
• You can verify your own code coverage by creating an account at Codecov.io

[Ayush0Chaudhary]

@palisadoes @TheHazeEffect @noman2002 @xoldyckk can you assign me this issue?? I have created PR for 2/3 of my issues