Converting ES6 to ES5 on the command line

I use the TypeScript compiler for this, since its output is more minimal than Babel's.

The following will transpile all src/*.js files into a file build.js:

Copynpm install typescript
npx tsc src/*.js --target ES5 --allowJs --outFile build.js

The output will only transpile ES6 syntax. It will not include any polyfills for missing APIs.