Report deprecated dependencies

[jfmengels]

What the rule should do:

Report deprecated dependencies. I see a few packages in the registry with DEPRECATED in the elm.json summary. I am thinking that we could use that as a sign that package is deprecated, and that it shouldn't be used anymore. Maybe we will be able to find other clues, like titles in the README containing deprecated.

What problems does it solve:

Allowing you to detect when a package becomes deprecated, in order to use the latest/best package out there for a problem.

Example of things the rule would report:

• A dependency of the project's summary is "DEPRECATED: Use xyz instead"

When (not) to enable this rule:

I am looking for:

Answers to the following questions:

• Should this rule take as a configuration a list of dependencies to allow? I'm thinking no, but if/when the package becomes deprecated, you may not want to fix it right now, as it can be a tedious/long task, depending on the package, meaning that you'd have to ignore the rule for a while. If we allow configuration, that will allow the users to keep the rule enabled and notice new deprecated dependencies.

• What do you think of the proposed deprecated signs? Can you think of others?

I am thinking it would fit very well with jfmengels/elm-review-rule-ideas#5 (which we have already enabled at my workplace), in something like elm-review-dependencies. But we might want to have a similar rule for noticing deprecated modules/functions, in which case they wouldn't be in the same package. And maybe that's okay.

[lue-bird]

I've seen/used

• archived github repo
• "deprecated" or "moved to/into ..." or "republished/continued under ..." or "unmaintained" or "usage discouraged" or "use/using ... instead" in the first non-title line / title / package description
• (maybe when the package only contains 1 dummy module)

There are some signs where a program can be sure that the package is deprecated.
It's not so clear for others. Here's how I'd do it:

• write a tool (an elm-review rule?) that lists all potential deprecated packages
  • adds packages that are deprecated for sure to the deprecatedPackages set and
  • asks you to manually check packages where it isn't 100% sure:
    • you're sure → adds packages to the deprecatedPackages
• automatically run that tool after some time again for the updated/newly released packages

deprecatedPackages =
    [ "jfmengels/review-common"
    , ...
    ]
        |> Set.fromList

isDeprecated packageName =
    Set.member packageName deprecatedPackages