Disable link prefetching in preview mode

[hatsumatsu]

Describe the feature you'd like to request

When using next's preview mode links via next/link are automatically prefetched as normal.
Since preview mode bypasses SSG and ISR, both the prefetch requests and the actual requests when clicking a link are server-rendered on request. this results in a high number of SSR requests in preview mode causing high load on external APIs and hosting services like vercel.

Describe the solution you'd like

Automatically (or via config) disable link prefetching in preview mode.

Describe alternatives you've considered

An alternative can be passing next/routers isPreview value to the prefetch prop of next/link. but setting prefetch={false} on next/link still prefetches on mouseenter.

[jonlow]

Would love this.

With preview enabled our server is getting hit with over 20 simultaneous uncached serverless requests which take many seconds to resolve.

[hatsumatsu]

The more I think about it the less I understand the reason why link prefetching is enabled in preview mode.
Are there any advantages beside the discussed downsides?

Maybe @timneutkens can shed some light on the subject since they closed this issue.

[wilsonneto-dev]

@hatsumatsu while this function doesn't get to production, what I recommend you is to abstract the next link with your own abstraction of it, then you can do this verification by yourself, and other ones that we need sometimes.

[wilsonneto-dev]

@timneutkens Can I work and send a PR with the feature described here? Or do you think this isn't necessary to be out-of-box?
Thank you guys

[woochica]

And actually documentation is also rather confusing, because it says:

Prefetching is only enabled in production.