onUploadProgress will be 100% before uploading process finished

Describe the issue

hey every body. in the first, sorry for my poor english language. i wrote some code for uploading some images and data together by formdata format in react-native. and i use node.js in backend side and every thing is ok. i can upload images. but problem has occurred when i want use onUploadProgress. then loaded parameter will be 100% immediately but the upload process take some minutes after that. just in record when i use ajax in js code it’s will be perfect so the problem is not from backend side. and it occurred just in react-native and the images select and crop by react-native-image-crop-picker.

here is my code:

Example Code

axios.post(api_url, formData, {
    onUploadProgress: progressEvent => {
        let {loaded, total} = progressEvent;
        console.log((loaded / total) * 100)
    },
    headers: {
        'Authorization: Bearer <authorization token>',
        'Content-Type': 'multipart/form-data'
    }
});

Expected behavior, if applicable

Environment

• Axios Version 0.21.0
• Node.js Version v14.15.1
• OS: ubuntu 18.04
• Additional Library Versions React Native 0.63.0

Additional context/Screenshots

[shannhastings]

I see the same issue. The onUploadProgress will ramp up to 100 pretty quick on a large file, but watching the network tab the file is still sending for a long time after progress has said it was 100. Then finally the promise will return. This does not have anything to do with localhost. Just upload a large file to say S3 and you will see, the onUploadProgress calls will finish WAY before the actual promise, i.e. the data, has been transmitted.

[snaptsoft]

Unfortunately also still seeing this issue using Expo 41.0 and React Native.