Question about next.js and fetch polyfill

Hello!

I have a dependency in my application that specifically relies on window.fetch being replaced with the whatwg-fetch polyfill. whatwg-fetch is a transitive dependency, so it should be ending up in my build, but it looks like next.js is replacing it with something else.

From reading the docs it seems like next provides it’s own fetch polyfill? Does that sound right, or am I totally off track here?

Thanks!

[samselikoff]

I’m not saying the optimization is not good! I’m just saying that Pretender explicitly added it as a dependency, and even explicitly imports from it here: https://github.com/pretenderjs/pretender/blob/master/src/index.ts#L2

It’s not that Mirage requires a specific implementation of window.fetch, it’s that Pretender literally depends on the actual whatwg-fetch dependency. The developers added it and imported it because they wanted specific behavior from that specific package – which should be a completely valid thing for anyone to do, for any package + for any reason!

I do not think you should change the defaults, I’m just saying, swapping out a dependency like this is extra/magical behavior with a lot of assumptions baked into it. Doing it is fine, but not providing an escape hatch seems completely wrong to me. And I would bet good money that many users will not deoptimize their apps unintentionally… the escape hatch should be an advanced configuration option that folks in situations like ours opt-into in very specific situations.

[balazsorban44]

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