so do npm install first(it will also install node 10 and 12 for testing, requires sudo) . then run
so below tests are for different versions of node and finally the latest one
sometimes for the initial run, the difference between new and existing versions is very high
like 34 ms for existing and just 9 ms for new. however running the tests again new(testNew.js) is usually 1.5 to 3 ms faster
npm run testNew10
npm run testExisting10
Am running new first to give existing the benefit of caching, if any. but still new constantly is better than existing
npm run testNew12
npm run testExisting12
npm run testNew
npm run testExisting