feat: added a way to upgrade wezterm-nightly

Casks/wezterm-nightly.rb

@@ -11,6 +11,27 @@
 
   # Unclear what the minimal OS version is
   # depends_on macos: ">= :sierra"
+
+  livecheck do 
+    url "https://github.com/wez/wezterm/releases/download/nightly/WezTerm-macos-nightly.zip"
+    strategy :header_match do |headers|
+      # matches last-modified header syntax
+      regex = /(\w{3}, )?(\d{1,2}) (\w{3}) (\d{4}) (\d{2}):(\d{2}):(\d{2}) GMT/
+      match = headers["last-modified"].match(regex)
+      if match.nil?
+        match = headers["x-ms-creation-time"].match(regex)
+      end
+
+      year = match[4]
+      month_idx = ["jan", "feb", "mar", "apr", "may", "jun", "jul", "aug", "sep", "oct", "nov", "dec"].index {|month| month == match[3].downcase}
+      month = (month_idx ? month_idx + 1 : 0).to_s.rjust(2,"0")
+      day = match[2].rjust(2, '0')
+      hour = match[5].rjust(2, '0')
+      minute = match[6].rjust(2, '0')
+      second = match[7].rjust(2, '0')
+      "#{year}#{month}#{day}#{hour}#{minute}#{second}"
+    end
+  end
 
   app "WezTerm.app"
   [
@@ -42,12 +63,6 @@ def caveats; <<~EOS
       /opt/homebrew/bin/ for M1 Mac.
 
     Removal of them is ensured by 'brew uninstall --cask #{token}'.
-
-    Since there's no version info included in the download URL of the nightly
-    build, NO update will be notified for 'wezterm-nightly' by Homebrew. (Not a
-    problem for non-nightly, regular released 'wezterm'.) To get the nightly
-    update, just run 
-    'brew upgrade --cask wezterm-nightly --no-quarantine --greedy-latest'.
   EOS
   end
 end