Merge pull request rails#53680 from jdelStrother/file-update-checker

Make FileUpdateChecker faster with many extensions

activesupport/CHANGELOG.md

@@ -28,4 +28,8 @@
 
     *Taketo Takashima*
 
+*   Make `ActiveSupport::FileUpdateChecker` faster when checking many file-extensions.
+
+    *Jonathan del Strother*
+
 Please check [8-0-stable](https://github.com/rails/rails/blob/8-0-stable/activesupport/CHANGELOG.md) for previous changes.

activesupport/lib/active_support/file_update_checker.rb

@@ -47,7 +47,7 @@ def initialize(files, dirs = {}, &block)
       end
 
       @files = files.freeze
-      @glob  = compile_glob(dirs)
+      @globs = compile_glob(dirs)
       @block = block
 
       @watched    = nil
@@ -103,7 +103,7 @@ def execute_if_updated
       def watched
         @watched || begin
           all = @files.select { |f| File.exist?(f) }
-          all.concat(Dir[@glob]) if @glob
+          all.concat(Dir[*@globs]) if @globs
           all.tap(&:uniq!)
         end
       end
@@ -145,10 +145,9 @@ def compile_glob(hash)
         hash.freeze # Freeze so changes aren't accidentally pushed
         return if hash.empty?
 
-        globs = hash.map do |key, value|
+        hash.map do |key, value|
           "#{escape(key)}/**/*#{compile_ext(value)}"
         end
-        "{#{globs.join(",")}}"
       end
 
       def escape(key)