Method shimCssText

packages/compiler/src/shadow_css.ts:175–199

(cssText: string, selector: string, hostSelector: string = '')

   * The hostSelector is the attribute added to the host itself.
   */
  shimCssText(cssText: string, selector: string, hostSelector: string = ''): string {
    // **NOTE**: Do not strip comments as this will cause component sourcemaps to break
    // due to shift in lines.

    // Collect comments and replace them with a placeholder, this is done to avoid complicating
    // the rule parsing RegExp and keep it safer.
    const comments: string[] = [];
    cssText = cssText.replace(_commentRe, (m) => {
      if (m.match(_commentWithHashRe)) {
        comments.push(m);
      } else {
        // Replace non hash comments with empty lines.
        // This is done so that we do not leak any sensitive data in comments.
        const newLinesMatches = m.match(_newLinesRe);
        comments.push(newLinesMatches?.join('') ?? '');
      }

      return COMMENT_PLACEHOLDER;
    });

    const scopedCssText = this._scopeCssText(cssText, selector, hostSelector);
    // Add back comments at the original position.
    let commentIdx = 0;
    return scopedCssText.replace(_commentWithHashPlaceHolderRe, () => comments[commentIdx++]);
  }

  /**
   * Process styles to add scope to keyframes.