static_file_migrator.rb

module Jekyll
    LIQUIDY_TAGS = ['{{', '}}', '{%', '%}']

    class StaticFile
        def is_liquidy
            case File.extname(self.path)
            when '.html'
                text = File.read(self.path)
                LIQUIDY_TAGS.any? { |tag| text.include? tag }
            else
                false
            end
        end

        def as_page
            Page.new(@site, @base, @dir, @name)
        end
    end

    class StaticFileMigrator < Generator
        safe true
        priority :highest

        def generate(site)
            liquidy_files = site.static_files.select { |file| file.is_liquidy }
            site.pages += liquidy_files.map { |static_file| static_file.as_page }
            site.static_files -= liquidy_files
        end
    end
end