BREAKING CHANGE(config): `--npm-version` & `--node-version` should be removed

[darcyclarke]

Summary

The --npm-version flag/option is confusing as we also have a top-level command npm version which is not configured by this at all. --npm-version is used by dependencies like npm-pick-manifest & libnpmpublish but not by the CLI itself. If not changed, this may cause issues when we go to implement command-specific configuration.

Exit Criteria

• remove --npm-version from being user-configurable & hard-code its downstream usage
• remove --node-version from being user-configurable
• investigate backporting warnings in v8.x

References

• https://docs.npmjs.org/cli/v8/using-npm/config#npm-version
• https://docs.npmjs.com/cli/v8/commands/npm-version
• RFC: Command Specific Configuration rfcs#566

[wraithgar]

node-version also

[ljharb]

What do those flags even do?

[wraithgar]

They are used in npm-pick-manifest to sort the packuments so that "working" ones bubble to the top... we are ok losing that imo.
They are used of course in logging engines conflicts and strict-engines checks. Strict engines being configurable is specifically the solution to the problem of mismatching engines, no need to override it there.

Finally it is used by arborist when installing optional dependencies. If the engine/npm versions aren't allowed it skips them.

[ljharb]

So they're overrides for package.json engines data?