Error 413 does not contain status code

#### Summary

In the follow code snippet,

axios.post('/api/files/new', formData, config)
    .then(response => this.fileUploaded(response.data, name, size))
    .catch(e => {
        console.log('error uploading file:')
        console.warn(e.response)
    })

if the api rejects with 413 (“file too large”), e.response is undefined. Multiple reasons can lead to a nul response, and we need to be able to distinguish. In this case, at the reject phase, that status is lost.

At the same time, servers should not have to attach response bodies for all forms of malformed requests.

#### Context

• axios version: 0.15.3
• Environment: vueJS/node custom project

[raygesualdo]

Hey all, I took a few minutes to troubleshoot this issue. Here are some things I found:

1. I created an example of @robbiemu’s code that works. The codesandbox can be viewed here: https://codesandbox.io/s/80jv7k528. Note that while the example makes a cross-domain request, the server is correctly configured for CORS. Let me know if that is helpful.
2. I found that, when making a cross-domain request, if the server isn’t correctly configured for CORS, axios returns an error without error.response populated. This is because the XHR request fails at the browser level (during the OPTIONS call), which is technically a network error. For network errors, axios does not provide a response because one is not provided by the browser. If one debugs the network error returned to axios from an invalid OPTIONS call, one will notice that there is no way to know the status.

[chinesedfan]

I think the reason is validateStatus. See my notes. And feel free to remind me if it is not solved.