Which harmony flag for default parameters in nodejs v4

Question

I'm using node.js v4.0.0 and am trying to get some code working without the need of transpiling it first. While most is working, I can't use

import

which might be because of the not finalized stage, but I also can't find a flag that enables it. I've tried all of them:

--harmony_modules (enable "harmony modules" (in progress))
  --harmony_array_includes (enable "harmony Array.prototype.includes" (in progress))
  --harmony_regexps (enable "harmony regular expression extensions" (in progress))
  --harmony_proxies (enable "harmony proxies" (in progress))
  --harmony_sloppy (enable "harmony features in sloppy mode" (in progress))
  --harmony_unicode_regexps (enable "harmony unicode regexps" (in progress))
  --harmony_reflect (enable "harmony Reflect API" (in progress))
  --harmony_destructuring (enable "harmony destructuring" (in progress))
  --harmony_sharedarraybuffer (enable "harmony sharedarraybuffer" (in progress))
  --harmony_atomics (enable "harmony atomics" (in progress))
  --harmony_new_target (enable "harmony new.target" (in progress))

(useless to say that I didn't use regexps for it... :))

While I get the reason for import, I don't see why default parameters are failing as they seem to be finalized and I can't find a flag which seems to handle it.

Is there a flag for import and default parameters?

The code that doesn't work is

class foo extends bar {
    constructor(options = {})
    ....
}

error is

unexpected = illegal token

Answer 1

Node 4 uses the version of V8 that shipped with Chrome 45 - and V8 v4.5.103.3 doesn't ship with default arguments, even behind a flag. Default arguments landed in the version of V8 that shipped with Chrome 49 and will be in Node 6+.

Answer 2

the flag is : --harmony_default_parameters