@atlaskit/app-provider/dist/es2019/theme-provider/utils/get-inline-theme-styles.js

A top level provider for the Design System.

import React from 'react';
import { themeImportMap } from '@atlaskit/tokens/artifacts/theme-import-map';
import { getThemeOverridePreferences } from '@atlaskit/tokens/get-theme-override-preferences';
import { getThemePreferences } from '@atlaskit/tokens/get-theme-preferences';

/**
 * TODO: Remove this React 18 compatibility guard when React 19 has shipped everywhere.
 * At that point, use `import { use } from 'react'` directly.
 */

const themeCssPromises = new Map();
function getThemeCssPromise(themeId) {
  let themeCssPromise = themeCssPromises.get(themeId);
  if (!themeCssPromise) {
    themeCssPromise = themeImportMap[themeId]().then(({
      default: css
    }) => css);
    themeCssPromises.set(themeId, themeCssPromise);
  }
  return themeCssPromise;
}
function getInlineThemeCss(themeId) {
  var _document$body$queryS, _document$body$queryS2;
  const reactUse = React.use;
  const isServer = globalThis.__SERVER__ === true || typeof document === 'undefined';
  if (isServer) {
    return reactUse === null || reactUse === void 0 ? void 0 : reactUse(getThemeCssPromise(themeId));
  }
  return (_document$body$queryS = (_document$body$queryS2 = document.body.querySelector(`style[data-theme="${themeId}"]`)) === null || _document$body$queryS2 === void 0 ? void 0 : _document$body$queryS2.textContent) !== null && _document$body$queryS !== void 0 ? _document$body$queryS : undefined;
}
/**
 * Resolves CSS for the themes applied by a ThemeProvider.
 *
 * During React 19 server rendering, `use()` suspends the provider subtree until
 * each requested CSS chunk is available. The resulting styles are rendered
 * immediately before that subtree. React 18 does not provide `use()`, so it
 * safely follows the existing path without inline CSS. During hydration, the CSS
 * is read from server-rendered style elements so the initial client tree matches.
 */
export function getInlineThemeStyles(theme, colorMode) {
  const themeState = {
    ...theme,
    colorMode,
    contrastMode: 'no-preference'
  };
  const themeIds = [...getThemePreferences(themeState), ...getThemeOverridePreferences(themeState)];
  return [...new Set(themeIds)].map(themeId => {
    const css = getInlineThemeCss(themeId);
    return css ? {
      id: themeId,
      css
    } : undefined;
  }).filter(style => style !== undefined);
}