Breaking: drop node v10/v13/v15 (fixes #14023)

[aladdin-add]

Prerequisites checklist

• I have read the contributing guidelines.

What is the purpose of this pull request? (put an "X" next to an item)

[ ] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[x] Other, please explain:

What changes did you make? (Give an overview)

fixes #14023

Is there anything you'd like reviewers to focus on?

no.

[btmills]

LGTM whenever we start merging breaking changes for v8.0.0.

[mdjermanovic]

We should also update prerequisites in README and getting-started.

[mdjermanovic]

LGTM, thanks!

[btmills]

Note to whomever merges this: try reverting #14771, which pinned fs-teardown to a version that still supports Node 10.12.

[aladdin-add]

#14771 has been merged. so I can revert it after rebasing.

[mdjermanovic]

Re fs-teardown, when we drop Node 10 it may be even better to set "fs-teardown": "^0.1.3" instead of reverting to ^0.1.0. That will leave v0.1.2 (which trims file contents) out of the range.

[aladdin-add]

rebased upstream master.

[mdjermanovic]

verify_files doesn't specify Node version, and the current default seems to be v10.24.1. After merging this PR, that job will be running on an unsupported version.

https://github.com/eslint/eslint/pull/14592/checks?check_run_id=3067449292 was successful with warnings, but the check will eventually break when we add more code that doesn't work in Node 10.

npm WARN notsup Unsupported engine for eslint@7.30.0: wanted: {"node":"^12.22.0 || ^14.17.0 || >=16.0.0"} (current: {"node":"10.24.1","npm":"6.14.12"})
npm WARN notsup Not compatible with your version of node/npm: eslint@7.30.0
npm WARN notsup Unsupported engine for fs-extra@10.0.0: wanted: {"node":">=12"} (current: {"node":"10.24.1","npm":"6.14.12"})
npm WARN notsup Not compatible with your version of node/npm: fs-extra@10.0.0

I think we should specify the Node version, but not sure which one would make the most sense - 12.22.0, 12.x, 14.x, or 16.x?

[nzakas]

Seems like 14.x would be the safest bet? Guaranteed ESM and stable.

[ErisDS]

Just wondering if there was a particular reason for pinning to 4.17.0 rather than an earlier version of 14?

Our project is an installed application, rather than a library & is currently pinned to 14.16.1. For us bumping Node to be able to upgrade a dev dependency doesn't make sense as it would impact 1000s of people 😬

Is there any chance you'd accept a PR to drop the pinned version by 1 version to 14.16.1?

[aladdin-add]

it was discussed in #14023 (comment).

a workaround is to use --ignore-engines, it may work well, but we cannot guarantee it will be working in all future versions.