1 files changed, 49 insertions, 0 deletions
diff --git a/activestorage/app/models/active_storage/filename.rb b/activestorage/app/models/active_storage/filename.rb
new file mode 100644
index 0000000000..35f4a8ac59
--- /dev/null
+++ b/activestorage/app/models/active_storage/filename.rb
@@ -0,0 +1,49 @@
+# Encapsulates a string representing a filename to provide convenience access to parts of it and a sanitized version.
+# This is what's returned by `ActiveStorage::Blob#filename`. A Filename instance is comparable so it can be used for sorting.
+class ActiveStorage::Filename
+  include Comparable
+
+  def initialize(filename)
+    @filename = filename
+  end
+
+  # Filename.new("racecar.jpg").extname # => ".jpg"
+  def extname
+    File.extname(@filename)
+  end
+
+  # Filename.new("racecar.jpg").extension # => "jpg"
+  def extension
+    extname.from(1)
+  end
+
+  # Filename.new("racecar.jpg").base # => "racecar"
+  def base
+    File.basename(@filename, extname)
+  end
+
+  # Filename.new("foo:bar.jpg").sanitized # => "foo-bar.jpg"
+  # Filename.new("foo/bar.jpg").sanitized # => "foo-bar.jpg"
+  #
+  # ...and any other character unsafe for URLs or storage is converted or stripped.
+  def sanitized
+    @filename.encode(Encoding::UTF_8, invalid: :replace, undef: :replace, replace: "�").strip.tr("\u{202E}%$|:;/\t\r\n\\", "-")
+  end
+
+  # Returns the sanitized version of the filename.
+  def to_s
+    sanitized.to_s
+  end
+
+  def as_json(*)
+    to_s
+  end
+
+  def to_json
+    to_s
+  end
+
+  def <=>(other)
+    to_s.downcase <=> other.to_s.downcase
+  end
+end