redoc/src/services/RedocNormalizedOptions.ts

import { RedocRawOptions } from '../components/OptionsProvider';
import { ThemeInterface } from '../theme';
import { isNumeric } from '../utils/helpers';

export class RedocNormalizedOptions {
  theme: ThemeInterface;
  scrollYOffset: () => number;

  constructor(raw: RedocRawOptions) {
    this.scrollYOffset = RedocNormalizedOptions.normalizeScrollYOffset(raw.scrollYOffset);
  }

  static normalizeScrollYOffset(value: RedocRawOptions['scrollYOffset']): () => number {
    // just number is not valid selector and leads to crash so checking if isNumeric here
    if (typeof value === 'string' && !isNumeric(value)) {
      const el = document.querySelector(value);
      if (!el) {
        console.warn(
          'scrollYOffset value is a selector to non-existing element. Using offset 0 by default',
        );
      }
      const bottom = (el && el.getBoundingClientRect().bottom) || 0;
      return () => bottom;
    } else if (typeof value === 'number' || isNumeric(value)) {
      return () => (typeof value === 'number' ? value : parseFloat(value));
    } else if (typeof value === 'function') {
      return () => {
        const res = value();
        if (typeof res !== 'number') {
          console.warn(
            `scrollYOffset should return number but returned value "${res}" of type ${typeof res}`,
          );
        }
        return res;
      };
    } else if (value !== undefined) {
      console.warn(
        'Wrong value for scrollYOffset ReDoc option: should be string, number or function',
      );
    }

    return () => 0;
  }
}