Drop base64 dependency, resolve Ruby warning

[Earlopain]

base64 is being used in the gem and so just adding it to the Gemfile is not sufficient. Instead of moving it to the gemspec, just replace it through the equivalent pack method call.

[amatsuda]

base64 is being used in the gem and so just adding it to the Gemfile is not sufficient.

Right. I knew it, and intentionally made it so. Bacause for instance activesupport depends on base64, most of real-world apps would be automatically depending on base64 already. And where that's not the case, e.g.) where running Ruby 3.3+ on Rails 6.0 or lower for some reason, users can resolve this problem on their side by adding base64 to their app dependency. Of course I could add base64 to this gem's dependency, but I did not choose that path because I thought we cannot guarantee that base64 would keep supporting all Ruby versions that we're going to support here.

And regarding this patch, it's true that reducing a silent dependency is nice, however this change adds a little bit of cryptic taste to the code for the readers.

So there's such trade offs, and I think in this case we could improve the code readability by adding a comment. Thus, in conclusion, I'll merge this. Thank you @Earlopain!

[Earlopain]

Thanks for the quick merge!

It's true that activesupport depends on it but I don't think implicitly relying on it like that would be a good idea, there's no guarantee that they will keep it. For example, mutex_m was dropped after initially being added. Plus, I think there's plenty usage in gems without any ties to rails/activesupport (or other gems that themselves depend on base64).

[koic]

I noticed this through the following CI failure:
https://github.com/rubocop/rubocop/actions/runs/10765086770/job/29848821614?pr=13208

@amatsuda Do you have any release plans for the new version of simplecov-html?

[amatsuda]

OK, just made a release (0.13.1) with this patch since here came a real user who wants this fix. Thanks!

[koic]

Great! Thanks!