@itwin/itwinui-react/esm/utils/hooks/useGlobals.js

A react component library for iTwinUI

import * as React from 'react';
import { ThemeContext } from '../../core/ThemeProvider/ThemeContext.js';
import { isUnitTest } from '../functions/dev.js';
let didLogWarning = {
  fontSize: false,
  themeProvider: false,
};
export const useGlobals = () => {
  let themeContext = React.useContext(ThemeContext);
  useThemeProviderWarning(themeContext);
  useRootFontSizeWarning();
  return themeContext;
};
export const useThemeProviderWarning = (themeContext) => {
  React.useEffect(() => {
    if (
      'development' === process.env.NODE_ENV &&
      !isUnitTest &&
      !didLogWarning.themeProvider &&
      !themeContext
    ) {
      console.error(
        'iTwinUI components must be used within a tree wrapped in a ThemeProvider.',
      );
      didLogWarning.themeProvider = true;
    }
  }, [themeContext]);
};
let useRootFontSizeWarning = () => {
  React.useEffect(() => {
    if (
      'development' === process.env.NODE_ENV &&
      !isUnitTest &&
      !didLogWarning.fontSize
    ) {
      let rootFontSize = parseInt(
        getComputedStyle(document.documentElement).fontSize,
      );
      if (rootFontSize < 16)
        console.error(
          'Root font size must not be overridden. \nSee https://github.com/iTwin/iTwinUI/wiki/iTwinUI-react-v2-migration-guide#relative-font-size',
        );
      didLogWarning.fontSize = true;
    }
  }, []);
};