I need to add test cases to an existing project, so I tried adding a new test target via
- File -> New -> Target -> Cocoa Touch Testing Bundle
- From the test navigator filter bar.
Even after adding, the target is not getting listed in the test filter bar.
May be because of this issue, Product -> Test option is diabled in my project.
Also I could see some differnce between the build setting in my project and another sample project I started in Xcode 6.1 in which Product -> Test option is enabled and everything working fine for Test cases.
Please find the build settings screen shots.

Any help is appreciated.
I had this exact problem. It turns out my existing project was creating my Cocoa Touch Testing Bundle with the .app extension when it should've been a .xctest extension.
You can fix this by going to your test target you created.
Build Settings > Wrapper Extensionand changing it fromapptoxctest.You may have to restart Xcode after this change to select your test target.
UPDATE: I found out the reason the Testing Bundle was becoming a
.appextension in the first place. I had to go to the main projectWrapper Extensionand make sure it was blank instead of.app. Apparently that was forcing all targets to become.appextension as well.