[Feature Request] Unable to use CDN that doesn't support HEAD requests

[stramel]

Context
I'm using an internal basic Git based CDN and it currently doesn't support HEAD requests. This makes it impossible to run storybook tests against the hosted versions.

test-runner/src/test-storybook.ts

Line 186 in 1ba363f

const res = await fetch(url, { method: 'HEAD', headers });

Proposed Solution
switch to using GET for the request instead of HEAD

Alternate Solutions

• adding a configuration flag for the type of request to make to ensure the server is running, such as --req-method=GET
• adding a CLI flag to be able to skip the server check such as --skip-server-check

[cfrank]

I understand the reasoning behind choosing to use a HEAD request, but to reduce these kinds of issues in the future I believe it makes sense to just switch this to a GET request.

There isn't any side-effects from this, since fetch buffers the response body and we never read from it.

(async () => {
    console.time('HEAD');
    const head = await fetch('https://raw.githubusercontent.com/json-iterator/test-data/master/large-file.json', {
        method: 'HEAD',
    });
    console.log(head.status);
    console.timeEnd('HEAD');

    console.time('GET');
    const get = await fetch('https://raw.githubusercontent.com/json-iterator/test-data/master/large-file.json');
    console.log(get.status);
    console.timeEnd('GET');
})();

200
HEAD: 104.648ms
200
GET: 93.117ms

In my tests the GET request usually resolve negligibly faster, though the primary benefit is just using the most basic request method and avoiding these types of issues being brought up in the future.

[github-actions]

🚀 Issue was released in v0.15.0 🚀