Merge pull request #10851 from kthchew/audit-empty-files

audit: check for installed empty files

Library/Homebrew/extend/pathname.rb

@@ -432,6 +432,7 @@ class Pathname
   def install_metafiles(from = Pathname.pwd)
     Pathname(from).children.each do |p|
       next if p.directory?
+      next if File.zero?(p)
       next unless Metafiles.copy?(p.basename.to_s)
 
       # Some software symlinks these files (see help2man.rb)

Library/Homebrew/formula_cellar_checks.rb

@@ -275,6 +275,48 @@ module FormulaCellarChecks
     "Python formulae that are keg-only should not create `pip3` and `wheel3` symlinks."
   end
 
+  INVALID_EMPTY_FILE_NAMES = %w[AUTHORS ChangeLog changes COPYING LICENSE NEWS README TODO].freeze
+  INVALID_EMPTY_FILE_EXTENSIONS = %w[.html .md .rst .txt].freeze
+  INVALID_EMPTY_FILE_DIRECTORIES = %w[bin libexec share/man share/doc].freeze
+  # Names and extensions to ignore, even if they are in a location within prefix given above
+  VALID_EMPTY_FILE_NAMES = %w[__init__ empty REQUESTED].freeze
+  VALID_EMPTY_FILE_EXTENSIONS = %w[.gitkeep .keep .keepme .stamp .typed].freeze
+
+  def check_empty_files(prefix)
+    return unless prefix.directory?
+
+    empty_files = prefix.children.select do |f|
+      next if INVALID_EMPTY_FILE_NAMES.exclude?(f.basename(".*").to_s) &&
+              INVALID_EMPTY_FILE_EXTENSIONS.exclude?(f.extname)
+      next unless File.zero?(f)
+
+      true
+    end
+
+    INVALID_EMPTY_FILE_DIRECTORIES.each do |dir|
+      path = prefix/dir
+      next unless path.directory?
+
+      # search all directories in INVALID_EMPTY_FILE_LOCATIONS and their subdirectories
+      Pathname.glob(path/"**/*").each do |p|
+        # Any files in the "valid" list should be skipped because they are expected to be empty
+        next if VALID_EMPTY_FILE_NAMES.include?(p.basename(".*").to_s)
+        next if VALID_EMPTY_FILE_EXTENSIONS.include?(p.extname)
+        next unless File.zero?(p)
+
+        empty_files << p
+      end
+    end
+
+    return if empty_files.empty?
+
+    <<~EOS
+      Unexpected empty files were installed.
+      The offending files are:
+        #{empty_files * "\n  "}
+    EOS
+  end
+
   def audit_installed
     @new_formula ||= false
 
@@ -293,6 +335,7 @@ module FormulaCellarChecks
     problem_if_output(check_shim_references(formula.prefix))
     problem_if_output(check_plist(formula.prefix, formula.plist))
     problem_if_output(check_python_symlinks(formula.name, formula.keg_only?))
+    problem_if_output(check_empty_files(formula.prefix))
   end
   alias generic_audit_installed audit_installed
 

Library/Homebrew/test/formula_installer_spec.rb

@@ -51,7 +51,8 @@ describe FormulaInstaller do
   specify "basic installation" do
     temporary_install(Testball.new) do |f|
       # Test that things made it into the Keg
-      expect(f.prefix/"readme").to exist
+      # "readme" is empty, so it should not be installed
+      expect(f.prefix/"readme").not_to exist
 
       expect(f.bin).to be_a_directory
       expect(f.bin.children.count).to eq(3)