Ignore missing files when cleaning old assets

lib/webpacker/commands.rb

@@ -10,15 +10,21 @@ def clean(count_to_keep = 2)
       files_in_manifest = process_manifest_hash(manifest.refresh)
       files_to_be_removed = files_in_manifest.flat_map do |file_in_manifest|
         file_prefix, file_ext = file_in_manifest.scan(/(.*)[0-9a-f]{20}(.*)/).first
-        versions_of_file = Dir.glob("#{file_prefix}*#{file_ext}").grep(/#{file_prefix}[0-9a-f]{20}#{file_ext}/)
-        versions_of_file.map do |version_of_file|
+
+        versions_of_file(file_prefix, file_ext).map do |version_of_file|
           next if version_of_file == file_in_manifest
 
           [version_of_file, File.mtime(version_of_file).utc.to_i]
         end.compact.sort_by(&:last).reverse.drop(count_to_keep).map(&:first)
       end
 
-      files_to_be_removed.each { |f| File.delete f }
+      files_to_be_removed.each do |f|
+        begin
+          File.delete f
+        rescue Errno::ENOENT
+          nil
+        end
+      end
     end
   end
 
@@ -45,4 +51,8 @@ def process_manifest_hash(manifest_hash)
         File.join(config.root_path, "public", value)
       end.flatten
     end
+
+    def versions_of_file(file_prefix, file_ext)
+      Dir.glob("#{file_prefix}*#{file_ext}").grep(/#{file_prefix}[0-9a-f]{20}#{file_ext}/)
+    end
 end

test/command_test.rb

@@ -30,4 +30,14 @@ def test_clean_command_works_with_nested_hashes_and_without_any_compiled_files
       assert Webpacker.commands.clean
     end
   end
+
+  def test_clean_command_does_not_fail_on_missing_files
+    Webpacker.commands.stub(:versions_of_file, %w[v1 v2 v3]) do
+      File.stub(:mtime, OpenStruct.new(utc: 0)) do
+        File.stub :delete, lambda { |n| raise Errno::ENOENT } do
+          Webpacker.clean
+        end
+      end
+    end
+  end
 end