jspm does not transpile code from ES6 to ES5

Question

Running jspm bundle-sfx some/input some/output.js does not transpile my code from ES6 to ES5. This makes the output file unusable.

Example contents of input file:

[1,2,3,4].map((i)=>i*i);

Answer 1

As explained by jspm author here:

ES6 transpilation only happens for ES6 modules, not ES6 files written in CommonJS.

It means that transpilation happens only for files using module syntax (import, export). It can be forced though by adding "format es6"; at the top of the source file as so:

"format es6";
[1,2,3,4].map((i)=>i*i);