Auto-detect nested containers. (#23322)

lib/hbc/container/base.rb

@@ -4,4 +4,15 @@ class Hbc::Container::Base
     @path = path
     @command = command
   end
+
+  def extract_nested(source)
+    container = Hbc::Container.for_path(source, @command)
+
+    return false unless container
+
+    ohai "Extracting nested container #{source.basename}"
+    container.new(@cask, source, @command).extract
+
+    true
+  end
 end

lib/hbc/container/bzip2.rb

@@ -8,8 +8,15 @@ class Hbc::Container::Bzip2 < Hbc::Container::Base
   def extract
     Dir.mktmpdir do |unpack_dir|
       @command.run!("/usr/bin/ditto",   args: ["--", @path, unpack_dir])
-      @command.run!("/usr/bin/bunzip2", args: ["-q", "--", Pathname(unpack_dir).join(@path.basename)])
-      @command.run!("/usr/bin/ditto",   args: ["--", unpack_dir, @cask.staged_path])
+      @command.run!("/usr/bin/bunzip2", args: ["--quiet", "--", Pathname.new(unpack_dir).join(@path.basename)])
+
+      src = Pathname.new(unpack_dir).children[0]
+
+      unless @cask.artifacts[:nested_container].empty? &&
+             extract_nested(src)
+        dest = @cask.staged_path.join(src.relative_path_from(Pathname.new(unpack_dir)))
+        FileUtils.mv(src, dest, force: true)
+      end
     end
   end
 end

lib/hbc/container/gzip.rb

@@ -8,8 +8,15 @@ class Hbc::Container::Gzip < Hbc::Container::Base
   def extract
     Dir.mktmpdir do |unpack_dir|
       @command.run!("/usr/bin/ditto",  args: ["--", @path, unpack_dir])
-      @command.run!("/usr/bin/gunzip", args: ["-q", "--", Pathname(unpack_dir).join(@path.basename)])
-      @command.run!("/usr/bin/ditto",  args: ["--", unpack_dir, @cask.staged_path])
+      @command.run!("/usr/bin/gunzip", args: ["--quiet", "--", Pathname.new(unpack_dir).join(@path.basename)])
+
+      src = Pathname.new(unpack_dir).children[0]
+
+      unless @cask.artifacts[:nested_container].empty? &&
+             extract_nested(src)
+        dest = @cask.staged_path.join(src.relative_path_from(Pathname.new(unpack_dir)))
+        FileUtils.mv(src, dest, force: true)
+      end
     end
   end
 end

lib/hbc/container/zip.rb

@@ -4,6 +4,23 @@ class Hbc::Container::Zip < Hbc::Container::Base
   end
 
   def extract
-    @command.run!("/usr/bin/ditto", args: ["-x", "-k", "--", @path, @cask.staged_path])
+    Dir.mktmpdir do |unpack_dir|
+      @command.run!("/usr/bin/ditto", args: ["-x", "-k", "--", @path, unpack_dir])
+
+      children = Pathname.new(unpack_dir).children
+
+      nested_container = children[0]
+
+      unless children.count == 1 &&
+             !nested_container.directory? &&
+             @cask.artifacts[:nested_container].empty? &&
+             extract_nested(nested_container)
+        children.each do |src|
+          dest = @cask.staged_path.join(src.relative_path_from(Pathname.new(unpack_dir)))
+          FileUtils.rm_r(dest) if dest.exist?
+          FileUtils.mv(src, dest, force: true)
+        end
+      end
+    end
   end
 end