diff --git a/2020/node/package-lock.json b/2020/node/package-lock.json
index 04b9a95..8cbc0b0 100644
--- a/2020/node/package-lock.json
+++ b/2020/node/package-lock.json
@@ -1569,9 +1569,9 @@
       "dev": true
     },
     "decode-uri-component": {
-      "version": "0.2.0",
-      "resolved": "https://registry.npmjs.org/decode-uri-component/-/decode-uri-component-0.2.0.tgz",
-      "integrity": "sha1-6zkTMzRYd1y4TNGh+uBiEGu4dUU=",
+      "version": "0.2.2",
+      "resolved": "https://registry.npmjs.org/decode-uri-component/-/decode-uri-component-0.2.2.tgz",
+      "integrity": "sha512-FqUYQ+8o158GyGTrMFJms9qh3CqTKvAqgqsTnkLI8sKu0028orqBhxNMFkFen0zGyg6epACD32pjVk58ngIErQ==",
       "dev": true
     },
     "deep-is": {
diff --git a/2022/ruby/Rakefile b/2022/ruby/Rakefile
index c620516..4808588 100644
--- a/2022/ruby/Rakefile
+++ b/2022/ruby/Rakefile
@@ -1,28 +1,26 @@
 require 'erb'
+require 'yard/doctest/rake'
 
 task :default => :test
 
-def what_day(arg=nil)
-  if arg
-    arg
-  else
-    if day = ENV.fetch("DAY", nil)
-      day
-    else
-      Time.now.day
-    end
-  end.to_s.rjust(2, '0')
+def what_day
+  ENV
+    .fetch("DAY", Time.now.day)
+    .to_i
+    .to_s
+    .rjust(2, '0')
 end
 
-task :run, [:day] do |t, args|
-  day = what_day(args[:day])
+task :run do |t, args|
+  day = what_day
   puts "OK. Let's run Day#{day}!\n\n"
   require "./day#{day}"
   Object.const_get("Day#{day}").go
 end
 
-task :test, [:day] do |t, args|
-  day = what_day(args[:day])
+desc "Run the tests my way; set env var DAY to run a day other than today"
+task :test do |t, args|
+  day = what_day
   puts "Wooo! Let's test Day#{day}!\n\n"
 
   File.open('./doctest_helper.rb', 'w') do |file|
@@ -35,7 +33,12 @@ task :test, [:day] do |t, args|
     TEST_HELPER
   end
 
-  abort unless system("yard doctest -v ./day#{day}.rb")
+  Rake::Task["yard:doctest"].invoke
+end
+
+YARD::Doctest::RakeTask.new do |task|
+  task.doctest_opts = %w[-v] << ENV.fetch("TESTOPTS", "").split(" ")
+  task.pattern = "./day#{what_day}.rb"
 end
 
 task :new do
@@ -57,6 +60,6 @@ rule ( /^day\d\d$/ ) do |task|
     input_file = "../inputs/#{task.name}-input.txt"
     system("pbpaste > #{input_file}")
     puts "📝 wrote the clipboard to #{input_file}, hope it was right:"
-    system("cat #{input_file}")
+    system("head -n 5 #{input_file}")
   end
 end
diff --git a/2022/ruby/day07.rb b/2022/ruby/day07.rb
index 9755448..2d73844 100644
--- a/2022/ruby/day07.rb
+++ b/2022/ruby/day07.rb
@@ -7,49 +7,73 @@ def self.go
 
   def initialize(input=nil)
     @input = input || real_input
-    @dirs = parse_input
+    @dirs = parse_input(@input)
   end
 
   # @example
   #   day.part1 #=> 95_437
   def part1
     @dirs
-      .map { |dir_name, _|
-        dirs
-          .select{ |subdir, _| subdir.start_with?(dir_name) }
-          .map{|dir, files| files.empty? ? 0 : files.map{|name,size| size}.reduce(&:+)}
-          .reduce(&:+)
-      }
+      .map { |dir_name, _| total_dir_size(dir_name) }
       .select{ |dir_size| dir_size < 100_000 }
       .reduce(&:+)
   end
 
+  # @example
+  #   day.part2 #=> 24_933_642
   def part2
+    disk_size = 70_000_000
+    space_needed_for_update = 30_000_000
+    current_free_space = disk_size - total_dir_size("root")
+    
+    delete_at_least_this_big = space_needed_for_update - current_free_space
+
+    @dirs
+      .map { |dir_name, _| total_dir_size(dir_name) }
+      .select{ |dir_size| dir_size > delete_at_least_this_big }
+      .sort
+      .first
   end
 
-  def parse_input
+  # @example e
+  #   day.total_dir_size('root/a/e') #=> 584
+  # @example a
+  #   day.total_dir_size('root/a') #=> 94853
+  # @example d
+  #   day.total_dir_size('root/d') #=> 24933642
+  # @example root
+  #   day.total_dir_size('root') #=> 48381165
+  def total_dir_size(dir_name)
+    @dirs
+      .select{ |subdir, _| subdir.start_with?(dir_name) }
+      .map{ |_name, size| size }
+      .reduce(&:+) 
+  end
+
+  # @example
+  #   day.parse_input(Day07::EXAMPLE_INPUT) #=> {"root"=>23352670, "root/a"=>94269, "root/a/e"=>584, "root/d"=>24933642}
+  def parse_input(input)
     cwd = "root"
-    @input
+
+    input
       .split("$ ")
-      .each_with_object({}) { |cmd_and_output, dirs|
-        lines = cmd_and_output.split("\n")
-        cmd = lines.shift
-        case cmd 
-        when "cd /"
-          cwd = "root"
-        when "cd .."
-          cwd = cwd.split("/")[0..-2].join("/")
-          cwd = "root" if cwd == ""
-        when /cd (\w*)/
-          cwd += "/#{$1}"
+      .each_with_object({}) { |command_and_output, dirs| # dirs is updated by and returned from this loop
+        command, output = command_and_output.split("\n", 2)
+
+        case command
+        when ""         ; :do_nothing
+        when "cd /"     ; cwd = "root"
+        when "cd .."    ; cwd = cwd.split("/")[0..-2].join("/")
+        when /cd (\w*)/ ; cwd += "/#{$1}"
+
         when "ls"
-          dirs[cwd] ||= { }
-          lines
-            .reject { |line| line.start_with?("dir")}
-            .map { |line| line.split(" ") }
-            .each { |size, filename| dirs[cwd][filename] = size.to_i }
-        else
-          :do_nothing
+          dirs[cwd] ||= output
+                          .split("\n")
+                          .reject { |line| line.start_with?("dir") }
+                          .map { |line| line.split(" ") }
+                          .reduce(0) { |dir_size, (size, _filename)|
+                            dir_size += size.to_i
+                          }
         end
       }
   end