feat(content): allow multipart requests without files.

[laipz8200]

Summary

related #3396.

Currently, a multipart request can only be sent when the files parameter is non-empty. This restriction limits cases where users might want to send data using multipart mode without attaching any files, which is possible in tools like Postman.

Change: Instead of requiring files to be non-empty, we could determine the need for a multipart request based on whether files is None rather than its emptiness. This would allow users to send multipart requests without attaching files if needed.

I think there is no significant documentation update required, so I have not made any changes. However, please let me know if any updates are needed.

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.

[lovelydinosaur]

Thanks. I've updated the tests to avoid private imports.

Do we think this is an improved behaviour? It does seem nice that an explicit files={} will enforce multipart. (On the other hand, if data and files are determined dynamically as in the cli we need to explicitly switch to None)

[laipz8200]

Thanks for the update!

My original plan was to make it easier to use multipart without having to carry files, which wasn’t as straightforward before.

I don’t use the cli much, so if this causes any issues, just let me know.

[sylann]

I don't think this change is correct. It seems to go against the spirit of your main change in the httpx/_content.py file.
It seems to prevent the fix from working when using the cli.
Although I am not familiar with this usage and I didn't look too much into it, so I don't know if it's even possible to do this through the cli.

[laipz8200]

Thank you for the review, I'll take a look at the CLI.

[ujayant]

@laipz8200 @tomchristie When do you plan to merge this feature? I am running into a similar issue

[ujayant]

@tomchristie @laipz8200 Is there a workaround for this in the older versions?

[laipz8200]

Is there a workaround for this in the older versions?

@ujayant Here is a workaround: https://github.com/encode/httpx/issues/3396#issuecomment-2508142475. I apologize for not being able to dedicate time recently to address this issue.

[ujayant]

Is there a workaround for this in the older versions?

@ujayant Here is a workaround: #3396 (comment). I apologize for not being able to dedicate time recently to address this issue.

I see this error when I try to use your example - chunk = self.file.read(self.CHUNK_SIZE) AttributeError: 'dict' object has no attribute 'read'. You will have to pass an empty file

[laipz8200]

Hi @tomchristie,

Sorry for the late reply — I think this PR is ready to be merged.

Regarding the point @sylann raised, I see it as more of a decision question: do we want to offer the same functionality for the CLI as well? If yes, should it be done in this PR?