Throws when frame.getFileName() is undefined

[Jarid Margolin]

TypeError: Path must be a string. Received undefined

Specifically I have been able to track down that this may occur on evals:

frame.getFileName()
// => undefined
frame.getEvalOrigin()
// eval at createProxy (/Users/jaridmargolin/Dropbox (Personal)/firstopinion/app/web-testdata-rewrite/node_modules/sinon/lib/sinon/spy.js:81:17)