Unable to add transformRequest to an endpoint

[existe-deja]

Version

module: 5.0.0-1618898588.9655d0e
nuxt: 2.15.4

Nuxt configuration

mode:

• universal
• spa

Nuxt configuration

login: {
  url: '/oauth/token/',
  method: 'post',
  headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
  transformRequest: [(data, headers) => {
    console.log('transformRequest', data)
    return data
  }]
}

Reproduction

https://codesandbox.io/s/pedantic-waterfall-1ze8d?file=/nuxt.config.js

What is expected?

I should be able to transform the request before it's sent.
According to the doc:

Each endpoint is used to make requests using axios. They are basically extending Axios Request Config.
But I can't add a request transformer specified in https://github.com/axios/axios#request-config

I'm trying to tranform the json data into a www-form-urlencoded data (stringified).
Poke #977

What is actually happening?

An error pops before the request is made. Specifying fn is not a function.

Steps to reproduce

Add a transformRequest Array in the endpoint definition. Or go to the reproduction link.

Additional information

Checklist

• I have tested with the latest Nuxt version and the issue still occurs
• I have tested with the latest module version and the issue still occurs
• I have searched the issue tracker and this issue hasn't been reported yet

[bmulholland]

Axios was recently updated, does that resolve this?