fix empty filenames are not considered a field (#26)

[cyantree]

This PR normalizes empty filenames to be handled as undefined. This allows sending multipart requests from the browser containing fields with content types which then will be handled as fields and not as files.

Linting fails. I have fixed most of the issues locally however there are some missing dependencies regarding the benchmark tests. Should I add the fixes I made to this PR?

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[cyantree]

I've marked it as draft because I haven't tested the new version with my usecase.

[kibertoad]

You can ignore linting warnings for benchmarks, they will not fail the build, we'll fix them later.

[kibertoad]

can you also add entry to MIGRATING.md, explaining the breaking change?

[cyantree]

Yes, I can explain the breaking change.

[kibertoad]

is this intentional?

[cyantree]

What do you mean exactly? This tests whether it's possible to use a non-json text field with empty filename. Or do you think this test isn't necessary?

[kibertoad]

Linting fixes unrelated to this PR are very welcome, but having them as a separate PR would be more convenient.

[Uzlopak]

Is this relevant to this PR?
simllll/busboy@c01a909

[kibertoad]

@Uzlopak I'd say so, and going with a config options (with blob by default) sounds like a good solution.

[kibertoad]

@cyantree Please let me know if you'll need any help with this!

[cyantree]

Is this relevant to this PR? simllll@c01a909

Yes, this is relevant. However I wouldn't recommend using blob as identifier as it can easily be used as a filename and therefore would lead to unexpected behaviour.

Regarding introducing a config option:
Yes, I can see this. But I wouldn't use blob as default there either because of the above reasons.
I think empty filenames should be sufficient and are usable with the browser api.
Another option would be using filenames that can't exist because of their structure. Maybe something like field://.

If you want to fix this quickly, then yes, it would be great if you could take over because atm I only can work at this when time allows it.

[Uzlopak]

I created a new PR with your work #52 . It also ensures that we are not breaking with original busboy.

[Uzlopak]

I created another PR #53 which i think handles the whole blob issue correctly.

[cyantree]

Obsolete as of #53.