Add a changelog.xml feed

I like authoring strong commits. Sharing my commits via RSS as a
changelog motivates me to keep up the good habits of writing strong
commits.

I like writing. I like process. I like writing about process. This silly
idea will give me a feedback loop.

lib/feed_target.rb

@@ -1,4 +1,6 @@
 class FeedTarget
+  include Singleton
+
   TARGET_PATH = Build.target_dir + "/feed.xml"
   AUTHOR = "Dan Ott".freeze
   TITLE = "Dan Ott's RSS Feed".freeze

lib/git_commit_changelog_target.rb

@@ -0,0 +1,77 @@
+class GitCommitChangelogTarget
+  include Singleton
+
+  TARGET_PATH = Build.target_dir + "/changelog.xml"
+  AUTHOR = "Dan Ott".freeze
+  TITLE = "Dan Ott's Website Changelog"
+  URL = "https://danott.website"
+
+  def to_target
+    self
+  end
+
+  def hydrate
+    self
+  end
+
+  def render
+    RSS::Maker.make("2.0") do |maker|
+      maker.channel.author = AUTHOR
+      maker.channel.updated = commits.map(&:date).max.to_s
+      maker.channel.about = URL
+      maker.channel.title = TITLE
+      maker.channel.link = URL
+      maker.channel.description = TITLE
+
+      commits.each do |commit|
+        maker.items.new_item do |maker_item|
+          maker_item.description = commit.description
+          maker_item.link = commit.link
+          maker_item.title = commit.title
+          maker_item.updated = commit.updated
+        end
+      end
+    end
+  end
+
+  def write
+    File.write(TARGET_PATH, render)
+    self
+  end
+
+  def commits
+    GitCommitJson.generate.map do |commit|
+      CommitRssItem.new(
+        subject: commit.fetch("subject"),
+        body: commit.fetch("body"),
+        date: Time.parse(commit.fetch("date")),
+        hash: commit.fetch("hash")
+      )
+    end
+  end
+
+  CommitRssItem =
+    Struct.new(:subject, :body, :date, :hash, keyword_init: true) do
+      def title
+        subject
+      end
+
+      def description
+        options = {
+          auto_ids: false,
+          hard_wrap: false,
+          input: "GFM",
+          syntax_highlighter: "rouge"
+        }
+        Kramdown::Document.new(body, options).to_html.strip
+      end
+
+      def link
+        "https://github.com/danott/website/commit/" + hash
+      end
+
+      def updated
+        date.to_s
+      end
+    end
+end

lib/git_commit_json.rb

@@ -0,0 +1,39 @@
+# Generate a minimal JSON structure from git commits.
+#
+# https://gist.github.com/varemenos/e95c2e098e657c7688fd#gistcomment-3542030
+# This prior art was helpful.
+#
+# https://git-scm.com/docs/pretty-formats
+# The git pretty formats docs will be helpful if more details are ever desired.
+class GitCommitJson
+  def self.generate(limit = 1000)
+    desired_json_structure = {
+      "body" => "%b",
+      "date" => "%cI",
+      "hash" => "%H",
+      "subject" => "%s"
+    }.freeze
+
+    ordered_attribute_keys = desired_json_structure.keys
+    ordered_attribute_value_placeholders = desired_json_structure.values
+
+    attribute_separator =
+      "🤞 I pledge to never type this in a git commit, lest I break my rudimentary parser"
+    commit_separator =
+      "...Same goes for this, because of the aforementioned parser breaking risks 🙃"
+
+    git_format =
+      ordered_attribute_value_placeholders.join(attribute_separator) +
+        commit_separator
+    log = `git log -n #{limit} --format="#{git_format}"`
+
+    log
+      .strip
+      .chomp(commit_separator)
+      .split(commit_separator)
+      .map do |commit|
+        ordered_attribute_values = commit.strip.split(attribute_separator)
+        Hash[ordered_attribute_keys.zip(ordered_attribute_values)]
+      end
+  end
+end

lib/includable.rb

@@ -10,7 +10,8 @@ module Includable
       <link rel="stylesheet" href="/stylesheets/pygments-default.css" media="(prefers-color-scheme: light)">
       <link rel="stylesheet" href="/stylesheets/pygments-monokai.css" media="(prefers-color-scheme: dark)">
 
-      <link rel="alternate" type="application/rss+xml" href="/feed.xml" title="Dan Ott's RSS Feed">
+      <link rel="alternate" type="application/rss+xml" href="/feed.xml" title="Dan Ott's Website RSS Feed">
+      <link rel="alternate" type="application/rss+xml" href="/changelog.xml" title="Dan Ott's Website Changelog">
 
       <script src="/javascripts/script.js"></script>
     </include-in-header>

site/changelog.rb

@@ -0,0 +1 @@
+GitCommitChangelogTarget.instance

site/feed.rb

@@ -1 +1 @@
-FeedTarget.new
+FeedTarget.instance