renovate/lib/util/url.ts

import urlJoin from 'url-join';

export function ensureTrailingSlash(url: string): string {
  return url.replace(/\/?$/, '/');
}

export function resolveBaseUrl(baseUrl: string, input: string | URL): string {
  const inputString = input.toString();

  let host;
  let pathname;
  try {
    ({ host, pathname } = new URL(inputString));
  } catch (e) {
    pathname = inputString;
  }

  return host ? inputString : urlJoin(baseUrl, pathname || '');
}

export function getQueryString(params: Record<string, any>): string {
  const usp = new URLSearchParams();
  for (const [k, v] of Object.entries(params)) {
    if (Array.isArray(v)) {
      for (const item of v) {
        usp.append(k, item.toString());
      }
    } else {
      usp.append(k, v.toString());
    }
  }
  const res = usp.toString();
  return res;
}