New feature to test file upload

[baconYao]

This is an amazing project! Thanks for your effort.
Do you have plan to develop new feature about uploading file?

[estrada9166]

Thanks for creating this issue!

It sounds something nice to have, I was thinking to add first a new method that can be used to test the whole resolver, maybe it can be useful to test the file uploading, what do you think?

[baconYao]

I'm a bit confused about the method you said. But I am very much looking forward to it.
Would you mind sharing your thoughts? Maybe we can discuss together.

[estrada9166]

Sure! What I'm thinking is using tester.graphql() and it will execute the mutation with the resolver... so, in case you're uploading a file, you can use sinon stub to stub the upload and return a custom value; that way you can test the whole resolver :)

Also, if you want to share how you are doing it, we can see how we can create a test case to it!

You can use this codesandbox so we can test it there