Logging a warning, if a file is skipped because it would be empty while generating all string files.

README.md

@@ -108,7 +108,7 @@ This command creates an Apple or Android strings file from the master strings da
 
 #### `generate-all-string-files`
 
-This command is a convenient way to call `generate-string-file` multiple times. It uses standard Mac OS X, iOS, and Android conventions to figure out exactly which files to create given a parent directory. For example, if you point it to a parent directory containing `en.lproj`, `fr.lproj`, and `ja.lproj` subdirectories, Twine will create a `Localizable.strings` file of the appropriate language in each of them. This is often the command you will want to execute during the build phase of your project.
+This command is a convenient way to call `generate-string-file` multiple times. It uses standard Mac OS X, iOS, and Android conventions to figure out exactly which files to create given a parent directory. For example, if you point it to a parent directory containing `en.lproj`, `fr.lproj`, and `ja.lproj` subdirectories, Twine will create a `Localizable.strings` file of the appropriate language in each of them. However, files that would not contain any translations will not be created; instead warnings will be logged to `stderr`. This is often the command you will want to execute during the build phase of your project.
 
 	$ twine generate-all-string-files /path/to/strings.txt /path/to/project/locales/directory --tags common,app1
 

lib/twine/runner.rb

@@ -74,7 +74,6 @@ module Twine
         raise Twine::Error.new "Could not determine format given the contents of #{@options[:output_path]}"
       end
 
-
       file_name = @options[:file_name] || formatter.default_file_name
       if @options[:create_folders]
         @strings.language_codes.each do |lang|
@@ -85,28 +84,37 @@ module Twine
           file_path = File.join(output_path, file_name)
 
           output = formatter.format_file(lang)
+          unless output
+            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any strings."
+            next
+          end
 
           IO.write(file_path, output, encoding: encoding)
         end
       else
-        language_written = false
+        language_found = false
         Dir.foreach(@options[:output_path]) do |item|
           next if item == "." or item == ".."
 
-          item = File.join(@options[:output_path], item)
-          next unless File.directory?(item)
+          output_path = File.join(@options[:output_path], item)
+          next unless File.directory?(output_path)
 
-          lang = formatter.determine_language_given_path(item)
+          lang = formatter.determine_language_given_path(output_path)
           next unless lang
 
+          language_found = true
+
+          file_path = File.join(output_path, file_name)
           output = formatter.format_file(lang)
+          unless output
+            Twine::stderr.puts "Skipping file at path #{file_path} since it would not contain any strings."
+            next
+          end
 
-          IO.write(File.join(item, file_name), output, encoding: encoding)
-
-          language_written = true
+          IO.write(file_path, output, encoding: encoding)
         end
 
-        unless language_written
+        unless language_found
           raise Twine::Error.new("Failed to generate any files: No languages found at #{@options[:output_path]}")
         end
       end

test/test_generate_all_string_files.rb

@@ -1,45 +1,71 @@
 require 'command_test_case'
 
 class TestGenerateAllStringFiles < CommandTestCase
-  class TestCreateFolders < CommandTestCase
-    def new_runner(create_folders)
-      options = {}
-      options[:output_path] = @output_dir
-      options[:format] = 'apple'
-      options[:create_folders] = create_folders
+  def new_runner(create_folders, twine_file = nil)
+    options = {}
+    options[:output_path] = @output_dir
+    options[:format] = 'apple'
+    options[:create_folders] = create_folders
 
+    unless twine_file
       twine_file = build_twine_file 'en', 'es' do
         add_section 'Section' do
           add_row key: 'value'
         end
       end
+    end
 
-      Twine::Runner.new(options, twine_file)
+    Twine::Runner.new(options, twine_file)
+  end
+
+  class TestDoNotCreateFolders < TestGenerateAllStringFiles
+    def new_runner(twine_file = nil)
+      super(false, twine_file)
     end
 
     def test_fails_if_output_folder_does_not_exist
       assert_raises Twine::Error do
-        new_runner(false).generate_all_string_files
+        new_runner.generate_all_string_files
       end
     end
 
+    def test_does_not_create_language_folders
+      Dir.mkdir File.join @output_dir, 'en.lproj'
+      new_runner.generate_all_string_files
+      refute File.exists?(File.join(@output_dir, 'es.lproj')), "language folder should not be created"
+    end
+
+    def test_prints_empty_file_warnings
+      Dir.mkdir File.join @output_dir, 'en.lproj'
+      empty_twine_file = build_twine_file('en') {}
+      new_runner(empty_twine_file).generate_all_string_files
+      assert_match "Skipping file at path", Twine::stderr.string
+    end
+  end
+
+  class TestCreateFolders < TestGenerateAllStringFiles
+    def new_runner(twine_file = nil)
+      super(true, twine_file)
+    end
+
     def test_creates_output_folder
       FileUtils.remove_entry_secure @output_dir
-      new_runner(true).generate_all_string_files
+      new_runner.generate_all_string_files
       assert File.exists? @output_dir
     end
 
-    def test_does_not_create_language_folders_by_default
-      Dir.mkdir File.join @output_dir, 'en.lproj'
-      new_runner(false).generate_all_string_files
-      refute File.exists?(File.join(@output_dir, 'es.lproj')), "language folder should not be created"
-    end
-
     def test_creates_language_folders
-      new_runner(true).generate_all_string_files
+      new_runner.generate_all_string_files
       assert File.exists?(File.join(@output_dir, 'en.lproj')), "language folder 'en.lproj' should be created"
       assert File.exists?(File.join(@output_dir, 'es.lproj')), "language folder 'es.lproj' should be created"
     end
+
+    def test_prints_empty_file_warnings
+      empty_twine_file = build_twine_file('en') {}
+      new_runner(empty_twine_file).generate_all_string_files
+
+      assert_match "Skipping file at path", Twine::stderr.string
+    end
   end
 
   class TestValidate < CommandTestCase