ng test throwing error

I am new to angular and working on angular project. when I do ng test to verify the unit testing, it throws me below error:

[PhantomJS 2.1.1 (Windows 8 0.0.0)]: Connected on socket mxj6K_YBly2AdstRAAAA with id 88288700 PhantomJS 2.1.1 (Windows 8 0.0.0) ERROR TypeError: useValue,useFactory,data is not iterable! at http://localhost:9876/_karma_webpack_/polyfills.bundle.js:853 PhantomJS 2.1.1 (Windows 8 0.0.0) ERROR TypeError: useValue,useFactory,data is not iterable! at http://localhost:9876/_karma_webpack_/polyfills.bundle.js:853

anybody got the same?