Thank you for the PR.
Do you mind to explain a bit more what problem you're trying to solve?
Thanks.

Sure. This is for the Particle API for internet-connected microcontrollers.

One API endpoint supports cloud compiling of firmware source code. It takes a multi-part upload with source code files as file uploads. The compile server puts the files in their relative paths, compiles them and returns a binary.

For example, if you send main.cpp, lib/gps.cpp and lib/gps.h the API expect these headers:

Content-Disposition: form-data; name="file"; filename="main.cpp"

Content-Disposition: form-data; name="file1"; filename="lib/gps.cpp"

Content-Disposition: form-data; name="file2"; filename="lib/gps.h"

Without the lib part the file hierarchy is flattened and the compilation will fail.

I see. Thanks for the details.

What if we do it in more standard compliant way? (https://developer.mozilla.org/en-US/docs/Web/API/FormData/append)

form.append('field1', data, 'lib/gps.cpp');

and

form.append('field1', data, {
  more: 'things',
  filename: 'lib/gps.cpp'
});

Thanks for the quick response and pointing to the standard.

The issue with your proposed approach is that it would be a breaking API change for form-data. Current callers expect an absolute path to be changed to a basename. (BTW I don't think this is captured in a test. I will add this to the PR)

Another implementation would be to add a flag includePath that would disable the basename call and pass the filename parameter directly.

I changed the implementation. Do you feel this is more standards-compliant?

form.append('field1', data, {
  more: 'things',
  filename: 'lib/gps.cpp'
  includePath: true
});

Coverage increased (+0.02%) to 96.703% when pulling e622bd8 on spark:relative-path into ddb3762 on form-data:master.

Is there a chance to merge this in? I can rebase if it helps.

Hey sorry, I've been far from this part of the internet for too long.

I like your solution that it doesn't break compatibility.
But other solution has it's simplicity factor (although it's a breaking change).

What do you feel like, if we add filepath option, would it work for you?

Welcome back to this corner of the Internet :)

Given that #355 was merged, I don't think this PR is necessary anymore. I'll close it in favor of #355.

👍