Work out what the relative path to get from from to to is.
i.e. Starting at from, what path would lead us to to.
Similar to Node.js's path.relative() but works outside the context of a filesystem, and assumes all paths are POSIX-style. So this also works for URL pathnames.
npm install get-relative-path
const getRelativePath = require('get-relative-path');
console.log(getRelativePath('/data/orandea/test/aaa/', '/data/orandea/impl/bbb'));
// ../../impl/bbb
console.log(getRelativePath('data/orandea/test/aaa/', 'data/orandea/impl/bbb'));
// ../../impl/bbb
console.log(getRelativePath(
new URL('https://localhost/data/orandea/test/aaa/').pathname,
new URL('https://localhost/data/orandea/impl/bbb').pathname
))
// ../../impl/bbb