Back to What I want to exist

Existence file

css-expect

A small browser-backed expectation library for CSS custom functions, and eventually native CSS mixins. It exists because emerging CSS logic should be tested by the browser that computes it, not by a JavaScript reimplementation guessing at CSS semantics.

Goal

Make it practical to write trustworthy tests for native CSS custom functions by loading CSS, applying a real property context, reading computed values, and returning diagnostics that explain browser support and expectation failures.

  • TypeScript
  • CSS
  • Testing

Now

Where it is

The project is focused on proving the custom-function API against current Chromium support, with Playwright as the browser automation layer and a conservative package surface for early adopters.

Next

What comes next

  • Keep README examples and generated diagnostics aligned with the shipped API.
  • Validate behavior when target CSS features are unsupported and make skip-or-fail policies clear.
  • Prepare the package for a careful first public release.