Refactored adapters loader;

[DigitalBrainJS]

Now we can set the adapter by name:

axios.get(url, {
  adapter: 'http' // 'xhr'
});

We can use auto-select from the list (If the adapter is not supported its handle is set to false and Axios tries to set the next one):

axios.get(url, {
  adapter:  ['xhr', 'http', function myCustomAdapter(config){}]
});

So now the default adapter config is adapter: ['xhr', 'http'];

In the future, when we have more than 2 adapters (fetch, http2, other frameworks/OS), we will be able to make separate builds with the selected adapters, and this adapter loader will deal with this by selecting the next available adapter or throwing an error like:

Error: Adapter 'fetch' is not available in the build

Closes #5264;
Closes #5263;

[kranzhoff]

Does this change apply to defaults as well, like:

axios.defaults.adapter = "http"; ?

[DigitalBrainJS]

Yes, the adapter is resolved right before its call.

[jasonsaayman]

Awesome!

[geekact]

Is that possible to export method getAdapter for people who wants to enhance the adapter?

import axios, { getAdapter } from 'axios';

const defaultAdapters = axios.defaults.adapter;
axios.defaults.adapter = (config) => {
  // do something
  const adapter = getAdapter(defaultAdapters);
  adapter(config);
  // do something
}

[yxw007]

Is that possible to export method getAdapter for people who wants to enhance the adapter?

import axios, { getAdapter } from 'axios';

const defaultAdapters = axios.defaults.adapter;
axios.defaults.adapter = (config) => {
  // do something
  const adapter = getAdapter(defaultAdapters);
  adapter(config);
  // do something
}

I want to do adapter enhancement, why not expose the adapter