Drop support of Node v10

[juergba]

Description of the Change

We drop support of Node v10 with end-of-life: 2021-04-30

[giltayar]

Can we make the engine minimum be 12.7.0? That version is the minimum for esm compatibility, which means that we can drop all kinds of ifs in the tests and the code around that.

I'd love to submit a pr around that, which should be part of this semver major release.

[giltayar]

I'd love to change the way we require/import tests files to always import, now that all the node versions support esm.

I can create it as a separate pr, but it should be part of the v9.0.0 version, as it could (very theoretically) break things.

[juergba]

Can we make the engine minimum be 12.7.0?

Yes, but in utils.supportsEsModules you are checking for >=v12.11. Now we take 12.7.0, sure?

I can create it as a separate pr [...]

Please, go ahead then. We don't have enough content for a serious semver major, yet.

[giltayar]

@juergba I'll get back to you on the minimum number. I'll check it while building the PR.

[giltayar]

I checked, and the version that finalized support for ESM was 12.17.0 (I confused 7 and 17). Note that the version that removed the "experimental ESM" warning was 12.20.0, which is a pretty late v12 version (the latest v12 version is 12.22.1).

This means that if I implement the PR that removes the "require and if fails then import", anybody using v12 that is earlier than v12.20.0 will get a warning from ESM. I'll go ahead and implement it anyway, and we can discuss this on that PR.

[juergba]

@giltayar I'm going to merge this PR, you can adjust the minimum version later on.
I hope you are alright in your country in these difficult times.

[giltayar]

I would love it if we could add this new PR to the next semver-major version of Node.js, and before the semver-major version is launched: #4635. This PR could only have been done when we dropped Node v10. The reasons are outlined in the PR.