Version number comparison & fix chained version renames

[angelikatyborska]

Resolves #123

TODO:

• numerical comparisons for versions
• fix chained version renames for Upgrade bitstyles to 6.0.0 #127
• recheck documentation for potential updates
• changelog entries

[angelikatyborska]

To be deleted after the code review, together with the corresponding classes in bitstyles.ex. I added this test to change a check that the new chaining behavior works as expected.

[andreasknoepfle]

I think it is a great idea to keep it. You could add the class mapping in as a compile time switch config
(add_version_test_classes), so they do not end up in the compiled versions for prod.

[angelikatyborska]

Hmm. let's say I do something like

# config.exs

if config_env() in [:test, :e2e] do
  config :bitstyles_phoenix, add_version_test_classes: true
end

I'm not even sure how to use it as a compile-time check in something like this:

defp downgrade_classname(class, target_version, current_version)
       when should_downgrade_from({4, 0, 0}, target_version, current_version) do
   mapping =
      case class do
        "u-overflow-y-auto" -> "u-overflow--y"
        # I can't sqeezee an if expression here
        "u-version-4" -> "u-version-2"
        _ -> class
      end
end

But I'm also thinking: if somebody adds bitstyles_phoenix to their project and compiles their project in test env (to run tests), then bitstyles_phoenix will include those 'test' classes in its source. Which means, if the user of the library is relying on class substitution in their app, and for some weird reason uses a class like u-version-4, then that class will get substituted in their app 🤔

[andreasknoepfle]

Dependencies are always compiled in prod ENV except when you state it on the dependency directly.
https://hexdocs.pm/mix/Mix.Tasks.Deps.html#module-dependency-definition-options

[andreasknoepfle]

For compile time switches you can even have a if block around the whole function definition

[angelikatyborska]

Done: 7a0fdc5 (#134)

[andreasknoepfle]

Lgtm 💚🚀 Nice work