Custom error handler

[andrew-womeldorf]

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This PR replaces handle_error with a new hook handleError. Closes #1857. This will, by default, print errors as was happening before, or allow the user to define their own error handler.

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[benmccann]

awesome. thanks!

[benmccann]

@Rich-Harris will you have access to global fetch to send the error off to an error reporting service as you desired with this solution?

[andrew-womeldorf]

@Rich-Harris will you have access to global fetch to send the error off to an error reporting service as you desired with this solution?

This may be naive of me, but any logging aggregation tool that I've used, I have an agent running on the server which periodically ships the logs from stdout back to the aggregator. The code in this PR, as I've observed, is only running server-side, so I don't think the client should ever have to be pushing logs back to the aggregator. So I think logging to stdout should be sufficient.

[andrew-womeldorf]

I'm not sure about the failing test from the last workflow run. all of the tests pass locally

[benmccann]

don't worry about it. most of the jobs passed. if it's just one failing then it's a flaky test

[Rich-Harris]

Thank you — made some tweaks in #2193, will close this in favour of that