v1.0.0

Major Changes

• #1 498ae6b Thanks @unional! - Support Storybook 10, and ship the addon as ESM only.

  The package is now published as @storybook-community/addon-css-user-preferences
  under the storybook-community org. It requires Storybook 10, builds with tsdown,
  and drops the CommonJS build: dist/cjs, dist/esm and dist/ts are gone, and
  ./preview and ./manager are reached through the exports map instead.

  The prefers-contrast global and cssUserPrefs parameter key was misspelled
  prefers-constrast. Any story that set the misspelled key must be updated,
  though it never had an effect.

  The addon-kit Header and Page example components have been removed, along
  with the panel and tab they were demonstrated in. Only the toolbar addon remains.

  Adds a CSF Next entry point with typed story parameters, and renders the toolbar
  icon at a visible size.

Minor Changes

• #5 27bcc1b Thanks @unional! - Emulate preferences for window.matchMedia, not just for CSS.

  The addon rewrote @media conditions in the CSSOM and nothing else, so a
  component that read a preference in JavaScript — a useMediaQuery hook, a theme
  library resolving its initial theme, a reduced-motion check gating an animation
  — kept seeing the real operating system value while the CSS around it was
  emulated, and the story rendered half emulated.

  While a preference is being emulated, window.matchMedia now answers for it. A
  query naming an emulated feature is rewritten to carry the emulated outcome and
  handed to the real implementation, so an unset preference, a viewport condition,
  and the rest of a compound query are still the browser's own answer, and a query
  shape the rewrite cannot express falls back to the real value rather than
  guessing.

  The returned MediaQueryList dispatches a change event when the toolbar
  changes a preference, through addEventListener('change'), onchange, and the
  deprecated addListener, so a subscriber follows the toolbar instead of reading
  a correct first value and then going stale.

  Returning every preference to its system default puts the browser's own
  window.matchMedia back, so a Storybook that is not emulating anything is left
  untouched.

• #4 58197bd Thanks @unional! - Apply preferences to stylesheets a story mounts as it renders.

  The rewrite ran from a Storybook useEffect, which fires after the play
  function, so a story shipping its own <style> could render with un-emulated
  CSS and its interaction tests could assert before the rewrite landed. The
  decorator now processes during render and observes the document for sheets
  that arrive later.

  The toolbar dropdowns follow the manager theme instead of the operating
  system's, which previously left dark controls inside a light manager.

  A preference the story pins in its own globals is now shown read-only.
  Storybook lets story globals win, so changing it from the toolbar was
  silently discarded.

Patch Changes

• #10 be11101 Thanks @unional! - Emulate preferences in stylesheets that arrive via <link>.

  A <link rel="stylesheet"> is in the document before its sheet is: link.sheet
  stays null until the request resolves, and document.styleSheets does not list
  the sheet before then. The rewrite triggered by the element's insertion therefore
  ran against a collection that did not yet contain the sheet that triggered it,
  and because loading is not a DOM mutation, nothing re-fired the observer when the
  sheet did arrive — so that stylesheet was never rewritten.

  A later re-render or any toolbar change picked the sheet up, which hid the
  problem while clicking through the UI. What it did not hide is the case the
  observer exists for: a play function runs before Storybook's effects, so an
  interaction test asserting on a rewritten condition raced the network and passed
  or failed on timing.

  The addon now waits for a pending <link> to load and rewrites once its sheet is
  there, so a linked stylesheet is emulated like an inline one.

• #9 5b19bf6 Thanks @unional! - Skip stylesheets the browser will not let the addon read, instead of failing the render.

  processCSS read .cssRules on every sheet in document.styleSheets. For a sheet that is not origin-clean the CSSOM getter throws SecurityError, and the "cssRules" in target guard did not help — cssRules is an accessor on CSSStyleSheet.prototype, so in is true for every sheet and the throw came one line later. Since processAll() runs on the render path, one cross-origin <link> — an ordinary Google Fonts or CDN stylesheet without crossorigin — took every story down.

  The read is now guarded: an unreadable sheet is skipped and reported once with a console.warn naming its href, and the remaining sheets are still rewritten.