Let the ls helper yield the file type too

Client code was repeating tests to branch. They are already done by the helper,
so let's yield the file type for the same price.

We also standardize client code expecting both types to check for :file first.

lib/zeitwerk/gem_loader.rb

@@ -42,13 +42,12 @@ def setup
     def warn_on_extra_files
       expected_namespace_dir = @root_file.delete_suffix(".rb")
 
-      ls(@root_dir) do |basename, abspath|
+      ls(@root_dir) do |basename, abspath, ftype|
         next if abspath == @root_file
         next if abspath == expected_namespace_dir
 
         basename_without_ext = basename.delete_suffix(".rb")
         cname = inflector.camelize(basename_without_ext, abspath).to_sym
-        ftype = dir?(abspath) ? "directory" : "file"
 
         warn(<<~EOS)
           WARNING: Zeitwerk defines the constant #{cname} after the #{ftype}

lib/zeitwerk/loader.rb

@@ -246,16 +246,16 @@ def all_expected_cpaths
 
           prefix = cpath == "Object" ? "" : cpath + "::"
 
-          ls(dir) do |basename, abspath|
-            if dir?(abspath)
+          ls(dir) do |basename, abspath, ftype|
+            if ftype == :file
+              basename.delete_suffix!(".rb")
+              result[abspath] = prefix + inflector.camelize(basename, abspath)
+            else
               if collapse?(abspath)
                 queue << [abspath, cpath]
               else
                 queue << [abspath, prefix + inflector.camelize(basename, abspath)]
               end
-            else
-              basename.delete_suffix!(".rb")
-              result[abspath] = prefix + inflector.camelize(basename, abspath)
             end
           end
         end
@@ -442,8 +442,8 @@ def all_dirs
 
     # @sig (String, Module) -> void
     private def define_autoloads_for_dir(dir, parent)
-      ls(dir) do |basename, abspath|
-        if ruby?(basename)
+      ls(dir) do |basename, abspath, ftype|
+        if ftype == :file
           basename.delete_suffix!(".rb")
           autoload_file(parent, cname_for(basename, abspath), abspath)
         else

lib/zeitwerk/loader/eager_load.rb

@@ -167,10 +167,10 @@ def load_file(path)
     while to_eager_load = queue.shift
       dir, namespace = to_eager_load
 
-      ls(dir) do |basename, abspath|
+      ls(dir) do |basename, abspath, ftype|
         next if honour_exclusions && eager_load_exclusions.member?(abspath)
 
-        if ruby?(abspath)
+        if ftype == :file
           if (cref = autoloads[abspath])
             cget(*cref)
           end
@@ -210,8 +210,8 @@ def load_file(path)
 
     suffix.split("::").each do |segment|
       while dir = dirs.shift
-        ls(dir) do |basename, abspath|
-          next unless dir?(abspath)
+        ls(dir) do |basename, abspath, ftype|
+          next unless ftype == :directory
 
           if collapse?(abspath)
             dirs << abspath

lib/zeitwerk/loader/helpers.rb

@@ -31,13 +31,15 @@ module Zeitwerk::Loader::Helpers
       if dir?(abspath)
         next if roots.key?(abspath)
         next if !has_at_least_one_ruby_file?(abspath)
+        ftype = :directory
       else
         next unless ruby?(abspath)
+        ftype = :file
       end
 
       # We freeze abspath because that saves allocations when passed later to
       # File methods. See #125.
-      yield basename, abspath.freeze
+      yield basename, abspath.freeze, ftype
     end
   end
 
@@ -46,11 +48,11 @@ module Zeitwerk::Loader::Helpers
     to_visit = [dir]
 
     while dir = to_visit.shift
-      ls(dir) do |_basename, abspath|
-        if dir?(abspath)
-          to_visit << abspath
-        else
+      ls(dir) do |_basename, abspath, ftype|
+        if ftype == :file
           return true
+        else
+          to_visit << abspath
         end
       end
     end