Merge pull request #174292 from Homebrew/findappcast

find-appcast: convert from developer script to command

cmd/find-appcast.rb

@@ -0,0 +1,69 @@
+# frozen_string_literal: true
+
+require "cli/parser"
+require "formula"
+require "open3"
+require "pathname"
+require "yaml"
+require "net/http"
+require "uri"
+
+module Homebrew
+  module_function
+
+  sig { returns(CLI::Parser) }
+  def find_appcast_args
+    Homebrew::CLI::Parser.new do
+      usage_banner <<~EOS
+        `find-appcast` <app_path>
+
+        Finds the appcast for a given app when a path is provided to the .app bundle.
+      EOS
+
+      named_args :app_path, min: 1
+
+      hide_from_man_page!
+    end
+  end
+
+  def find_appcast
+    args = find_appcast_args.parse
+
+    app = Pathname.new(args.named.first)
+    find_sparkle(app) || find_electron_builder(app)
+  end
+
+  def verify_appcast(appcast_type, *urls)
+    print "Looking for #{appcast_type} appcast… "
+    urls.each do |url|
+      next unless url_exist?(url)
+
+      puts "Found!"
+      puts "  #{url}"
+      return true
+    end
+    puts "Not found."
+    false
+  end
+
+  def url_exist?(url)
+    return false unless url
+
+    system("curl", "--silent", "--location", "--fail", url, out: File::NULL)
+  end
+
+  def find_sparkle(app)
+    plist = app.join("Contents/Info.plist")
+    url = Open3.capture3("defaults", "read", plist.to_path, "SUFeedURL").first.strip
+    verify_appcast("Sparkle", url)
+  end
+
+  def find_electron_builder(app)
+    appcast_file = app.join("Contents/Resources/app-update.yml")
+    unless appcast_file.exist?
+      verify_appcast("electron-builder", false)
+      return false
+    end
+    YAML.load_file(appcast_file)
+  end
+end