var re = new RegExp(r.from, "g");

It should be something like:

        var re = new RegExp(escapeRegExpPattern(r.from), "g");

Otherwise, for example, any special RegExp characters such as . or ? in the input are not interpreted as the raw characters anymore. As a result the ${owner}/${repo}.svg?branch=${old} replacement currently does not work.

An example escapeRegExpPattern implementation can be found here: https://stackoverflow.com/a/9310752/96656

You could also use this String.prototype.replaceAll polyfill: https://github.com/es-shims/String.prototype.replaceAll (And then in the future, remove it once all Node.js versions you care about get native support.) That way, you don't have to bother converting the search strings into regular expressions just to do global replacement.