node 18.x compatibility

[epaminond]

Same code that runs fine on node 16.x (basic mg.messages.create) fails on node 18.x with following error

TypeError: fetch failed
    at Object.processResponse (node:internal/deps/undici/undici:5575:34)
    at node:internal/deps/undici/undici:5901:42
    at node:internal/process/task_queues:140:7
    at AsyncResource.runInAsyncScope (node:async_hooks:202:9)
    at AsyncResource.runMicrotask (node:internal/process/task_queues:137:8) {
  cause: TypeError: object2 is not iterable
      at action (node:internal/deps/undici/undici:1661:39)
      at action.next (<anonymous>)
      at Object.pull (node:internal/deps/undici/undici:1709:52)
      at ensureIsPromise (node:internal/webstreams/util:172:19)
      at readableStreamDefaultControllerCallPullIfNeeded (node:internal/webstreams/readablestream:1884:5)
      at node:internal/webstreams/readablestream:1974:7
}

node: 18.1.0
mailgun.js: 6.0.1

[epaminond]

A workaround for this is to run node 18.x with --no-experimental-fetch flag.

[epaminond]

Seems like this is coming from ky-universal package.

[zacharytyhacz]

I am getting this as well

(node:93936) ExperimentalWarning: The Fetch API is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
5/14/2022 3:10:10 PM TypeError: fetch failed
    at Object.processResponse (node:internal/deps/undici/undici:5575:34)
    at node:internal/deps/undici/undici:5901:42
    at node:internal/process/task_queues:140:7
    at AsyncResource.runInAsyncScope (node:async_hooks:202:9)
    at AsyncResource.runMicrotask (node:internal/process/task_queues:137:8) {
  cause: TypeError: object2 is not iterable
      at action (node:internal/deps/undici/undici:1661:39)
      at action.next (<anonymous>)
      at Object.pull (node:internal/deps/undici/undici:1709:52)
      at ensureIsPromise (node:internal/webstreams/util:172:19)
      at readableStreamDefaultControllerCallPullIfNeeded (node:internal/webstreams/readablestream:1884:5)
      at node:internal/webstreams/readablestream:1974:7
      at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
}

• Node Version: v18.1.0
• mailgun.js version : ^6.0.1

[zacharytyhacz]

Interesting, I wonder why they don't just use fetch or axios

[sholladay]

Ky maintainer here. I'd be happy to help debug if someone can provide me with an easy and minimal repro environment so I don't want to have to set up a Mailgun API key, etc.

What I can say right now is that if this problem is indeed related to Node 18 and its newly implemented fetch(), then this should be very easy to solve. We can always fallback to node-fetch even if there's no other simple solution.

EDIT: I will spend time on this when Mailgun wants to use Ky again.

[zacharytyhacz]

Ky maintainer here. I'd be happy to help debug if someone can provide me with an easy and minimal repro environment so I don't want to have to set up a Mailgun API key, etc.

What I can say right now is that if this problem is indeed related to Node 18 and its newly implemented fetch(), then this should be very easy to solve. We can always fallback to node-fetch even if there's no other simple solution.

Hello @sholladay - thank you for noticing this issue thread

🙏 🙏 🙏 🙏

Adding support for Node 18.x would be amazing thank you

[olexandr-mazepa]

Hello
@epaminond and @zacharytyhacz can you share a code you wrote to reproduce the issue?
Something is different on my machine than on yours and I don't have this error, so let's start with code implementation.

I like the idea of switching to Axios usage instead of ky.
@zacharytyhacz, thank you a lot for the PR. I will need to spend some additional time testing and checking corner cases, but I plan to publish a new major version of SDK by the end of the week.

@sholladay, thank you for your attention on this issue. There is one more issue that you may be interested to take a look at.
#272
The eighteenth version of node.js by default enables experimental global fetch API. I think this is the reason for these issues.

[epaminond]

@sholladay , you can try this code to reproduce an error: https://github.com/epaminond/mailgun-error-repro
Basically error occurs even if you don't supply correct MAILGUN_API_KEY and MAILGUN_DOMAIN.
Hope this helps!

CC @olexandr-mazepa