@atlaskit/css-reset/dist/es2019/utils/evaluate-inner.js

A base stylesheet for the Atlassian Design System.

/**
 * The below code is inspired by the css function in styled components
 * https://github.com/styled-components/styled-components/blob/master/packages/styled-components/src/types.js
 */
export default function evaluateInner(styles, ...interpolations) {
  return flatten(interleave(styles, interpolations)).join('');
}
function interleave(strings, interpolations) {
  const result = [strings[0]];
  for (let i = 0; i < interpolations.length; i++) {
    result.push(interpolations[i], strings[i + 1]);
  }
  return result;
}
function flatten(chunks, executionContext = {
  theme: {
    __ATLASKIT_THEME__: {
      mode: 'light'
    }
  }
}) {
  return chunks.reduce((ruleSet, chunk) => {
    /* Remove falsey values */
    if (chunk === undefined || chunk === null || chunk === false || chunk === '') {
      return ruleSet;
    }

    /* Flatten ruleSet */
    if (Array.isArray(chunk)) {
      ruleSet.push(...flatten(chunk, executionContext));
      return ruleSet;
    }

    /* Either execute or defer the function */
    if (typeof chunk === 'function') {
      if (executionContext) {
        const nextChunk = chunk(executionContext);
        ruleSet.push(...flatten([nextChunk], executionContext));
      } else {
        ruleSet.push(chunk);
      }
      return ruleSet;
    }
    // TODO: Fix bug in lint rule, this shouldn't be an error!
    ruleSet.push(isPlainObject(chunk) ? objToCss(chunk) : chunk.toString());
    return ruleSet;
  }, []);
}
function isPlainObject(x) {
  // TODO: Fix bug in lint rule, this shouldn't be an error!
  return typeof x === 'object' && x.constructor === Object;
}
function hyphenate(value) {
  const uppercasePattern = /([A-Z])/g;
  return value.replace(uppercasePattern, '-$1').toLowerCase();
}
function objToCss(obj, prevKey) {
  const css = Object.keys(obj).filter(key => {
    const chunk = obj[key];
    return chunk !== undefined && chunk !== null && chunk !== false && chunk !== '';
  }).map(key => {
    if (isPlainObject(obj[key])) {
      return objToCss(obj[key], key);
    }
    return `${hyphenate(key)}: ${obj[key]};`;
  }).join(' ');
  return prevKey ? `${prevKey} {
    ${css}
  }` : css;
}