Content type changed from multipart/form-data to application/x-www-form-urlencoded

[Flamenco]

My content-type header of multipart/form-data is getting replaced with another content-type. This was not an issue until I switched to v1.0.x

const api = axios.create({
 headers: {
  'Content-Type': 'application/json'
 }
})

const formData = new FormData()
formData.append('file', file)
api.post('endpoint', formData, {
  headers: {
   'Content-Type': 'multipart/form-data'
 }
})

However, this works:

axios({
 url: 'endpoint',
 method: 'post',
 data: formData,
 headers: {
   'Content-Type': 'multipart/form-data'
 }
})

This was sent with the old version, and the workaround mentioned:

And this started happening when I upgraded.

[GamalC]

I believe that I had to adjust to some changes made in headers processing as well. Adding here in case it helps someone.

I am sending an Axios POST request with the following data:
var data = {'key1': value1, 'key2': value2 };

And had Headers:
var default_headers = { ... 'Content-type': 'application/x-www-form-urlencoded', ...};

In version 0.22.0, the decoded content was:
{"key1":"value1","key2":"value2"}

In version 1.0.0+ it is now:
key1=value1&key2=value2

The update now seems to be the correct processing if Content-Type is set to 'application/json' (which now seems to work in 1.0.0+) but it initially caused a crash after updating when I tried to load the JSON.

[physicsSorcererKing]

@Flamenco Don't add 'Content-Type': 'multipart/form-data' by yourself before this issue is solved.
axios will automatically do this if config.data's type is FormData
see https://github.com/axios/axios/tree/main#formdata

[DigitalBrainJS]

Can you reproduce the issue here?

[Flamenco]

@physicsSorcererKing I am adding it because my base axios, that had all sorts of headers and logic, declared content type of "application/json", as shown. I need to override it. Perhaps overriding it as 'undefined' might work.

[physicsSorcererKing]

@DigitalBrainJS I found I spelled lowercase content-type caused it happened.
Not sure is this @Flamenco 's case.

[DigitalBrainJS]

OK. I found the problem, so I will fix it soon.

[jasonsaayman]

Hi 👋

Please try the latest pre-release by running the following:

npm i axios@1.2.0-alpha.1

Please provide feedback in either the pinned issue or discussion thread 🧵

[FelipeEduardoR2]

@jasonsaayman
Eu testei e no meu caso resolveu!
(I tested and it's ok!)

[darkvertex]

I also had an issue where my headers were getting ignored during a multipart formdata call and Axios was submitting it as a urlencoded form data, which my backend did not likey.

axios@1.2.0-alpha.1 fixed this behaviour for me and my multipart calls work again. 🎉

[Soneji]

Same issue, axios 1.2.0 is out now and fixes this!