capture-group-ex.js

/* Named capture groups (ECMAScript regex flavour)
 */

  const rex = new RegExp(
    "(?<protocol>https://)"  +   // capture group https://
    "(?<gitService>[^:/]+)"  +   // anything not a : or /  
    "/"                      +
    "(?<orgName>[^/]+)"      +   // capture org name
    "/"                      +
    "(?<repo>[^#]+)"         +   // capture repo
    "#?"                     +   // optional branch separator

    "(?<branch>.+)?",            /* optionally capture branch 
                                  * if it doesn't match branch will be undefined
                                  */

    "i"                          // case insensitive
  );


const urls = [
  "https://github.com/truffle-box/metacoin-box#fix/one",
  "https://github.com/truffle-box/metacoin-box"
];

for (const url of urls) {
  console.log(`\nURL: ${url}`);
  const match = url.match(rex);
  const { groups: G } = match;
  console.log(G);
  const optionalBranch = G['branch'] ? `#${G['branch']}` : '';
  console.log(`Normy Url: ${G['protocol']}${G['gitService']}:${G['orgName']}/${G['repo']}${optionalBranch}`);
}