Fix: Error thrown when fetch argument is not a string or a Request object.

[vierno]

Hello,

When using fetch and the first parameter of fetch is undefined, raven is throwing an error:

> fetch(undefined)
< Uncaught TypeError: Cannot read property 'url' of undefined

This fix covers the cases where the first arg of fetch is neither a string or a Request object.

[kamilogorek]

This will always return true, as typeof 'Request' is always string.
Use 'Request' in _window to verify that Request is available.

[kamilogorek]

Can you use url = '' + url instead? We use this syntax throughout the codebase.

[kamilogorek]

Hey!
Thanks for contributing. There are just two things that need some changes.
We also need a test case for this scenario.

[vierno]

Hello, @kamilogorek ,

I've made the requested changes and updated the pull request.

Thank you!

[kamilogorek]

Thanks!

[benvinegar]

@vierno so, I agree Raven shouldn't choke when it gets an argument like this, but I'm curious if there's any actual defined behavior for fetch(123) or fetch(undefined)? The browser lets me do it, but it's not clear what's actually happening.

[vierno]

@benvinegar , the browser uses the string representation of the argument as the url. So fetch(undefined) gives the same result of fetch("undefined")

[kamilogorek]

Unfortunately this test is failing on IE10/11/Safari10, but I'll try to fix it. Unfortunately, our setup at the moment doesn't allow to run SauceLabs tests for non-organization members. We're working on fixing this setup as well.

[benvinegar]

the browser uses the string representation of the argument as the url. So fetch(undefined) gives the same result of fetch("undefined")

@vierno – Ah, thanks for the clarification.