Should declare a required node version in package.json

[hallvors]

I had to downgrade a project from running on Node 18 - 22 to Node 16 for reasons not related to date-fns, and it cost me a bit of debugging time to understand that my date calculations are not wrong, @date-fns/tz is not actually compatible with Node 16:

$ node
Welcome to Node.js v16.17.0.
Type ".help" for more information.
> const { TZDateMini } = require('@date-fns/tz/date/mini');
undefined
>  new TZDateMini(Date.now())
TZDateMini Invalid Date { internal: Invalid Date }

Setting a requirement in package.json so I would be warned on install would be helpful:

  "engines": {
   "node": ">=18.0.0"
  }

(I have not verified that 18.0.0 is indeed the minimum requirement)

[kossnocorp]

Fair enough. I plan to add support to most of the environments that have Intl (#65), but having a minimal Node.js version defined is a good thing.

I'm not sure, though, what to base it on, as even the oldest versions can be polyfilled (i.e., Format.JS), and if syntax is unsupported, transpiled. Then the hard requirement will make life very difficult for some, especially when defined in a transitive dependency.

[hallvors]

Good point, and it's obviously a bit of a corner case to have written and tested code for a more recent Node version and downgrading to an older one. Is it possible to detect the missing API or bug that causes this problem on Node 16 and warn in a more targeted way? Apologies, I have not debugged the actual core reason in date-fns code, so I don't know if this is easy or hard. If you would be open to a PR I could look into it a bit more. Your library is very useful and helpful overall!