Significant Performance Improvement with only a few lines of code

[x9sim9]

Hi, so we have been using tailwind-merge across all of our components of our site, we did not notice it at first but over time this utility became a huge performance bottleneck adding multiple seconds to our erb rendering time.

By adding Rails.cache on the classnames we saw performance improvements of 4 to 8 times in page load speed for our pages.

classnames = "my tailwind classes"

Rails.cache.fetch(classnames) do
  TailwindMerge::Merger.new(
    config: {
      conflicting_class_groups: {
        **TailwindMerge::Config::DEFAULTS[:conflicting_class_groups],
        text: %w[xs xsm sm md lg xl 2xl 3xl 4xl]
      },
      class_groups: {
        **TailwindMerge::Config::DEFAULTS[:class_groups],
        "font-size" => [{ "text" => ["base", TailwindMerge::Config::IS_TSHIRT_SIZE, TailwindMerge::Config::IS_ARBITRARY_LENGTH, "xsm"] }]
      }
    }
  ).merge(classnames)
end

While Rails.cache may not be the best solution for non Rails projects caching in general has a huge impact on performance.

Hope this helps someone :-)