Improve handling cache folder and cache file paths

[ashmaroli]

This is to ensure that the cache folder always resides under the site's source path.
A simple File.join leaves security holes for configs like following:

webmentions:
  cache_folder: "../../.foo-cache"

An additional gain is a utility method Jekyll::WebmentionIO.cache_file to simplify creating cache_file paths.

However, Jekyll::WebmentionIO.bootstrap has now changed its signature to accept a required-parameter site (which is simply the current Jekyll::Site instance)

[aarongustafson]

Thanks for this! What do you see as the risk of a signature change like this? I’m not seeing one from my end. Could it cause any issues for generators or commands?

[ashmaroli]

What do you see as the risk of a signature change like this?

None from my side as well, since to me, this plugin is the only thing that's gonna be calling that method.. But still, I thought I'd emphasize the change in case you were aware of any add-ons for this gem that may use that method.....

[aarongustafson]

@ashmaroli I am not. But maybe I’ll make this a major version bump just to be safe.

[ashmaroli]

An unforeseen side-effect of this is that the :after_init hook was introduced only in Jekyll 3.2.., ergo, older versions will now unfortunately break..

The gemspec will have to reflect this, IMO..

jekyll-webmention_io/jekyll-webmention_io.gemspec

Line 39 in feb4e03

s.add_runtime_dependency "jekyll", ">= 2.0", "< 4.0"

Let's not rush into a patch release immediately, though.. I may open a couple of "cleanup PRs" based on RuboCop reports.. 😉 ...

[aarongustafson]

Is there a good way to provide a fallback? We have a few of those in the source.

[ashmaroli]

Is there a good way to provide a fallback? We have a few of those in the source.

You mean continue support for < Jekyll 3.2.0 ..?
The sane way would be to add a :respond_to? check..

This repo really needs a working Continuous Integration Coverage to prevent such mistakes in the future..