I'm having difficulty getting org-babel to evaluate this block of code with

emacs v24.5
node v5.0.0
babel-node v.6.6.5

 #+BEGIN_SRC js :cmd "babel-node" let arr = [1, 2]; let [x, y] = arr; console.log(x); console.log(y); #+END_SRC 

The output looks like this

/tmp/babel-3700Vaq/js-script-37003RN:2
 let arr = [1, 2]; ^^^ SyntaxError: Block-scoped declarations (let, const, function, class) not yet supported outside strict mode at exports.runInThisContext (vm.js:53:16) at Module._compile (module.js:404:25) at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:5) at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7) at Module.load (module.js:356:32) at Function.Module._load (module.js:311:12) at Function.Module.runMain (module.js:457:10) at /usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:161:27 at Object. (/usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:162:7) at Module._compile (module.js:425:26)* 

But this source block seems fine

 #+BEGIN_SRC js :cmd "babel-node" const numbers = [10,20,30,50]; const multiplyBy10 = numbers.map(a => a * 10); console.log(multiplyBy10); #+END_SRC #+RESULTS: | 100 | 200 | 300 | 500 | 

>Edit: Added self executing function with "use strict"

 #+BEGIN_SRC js :cmd "babel-node" (function xy() { "use strict"; let arr = [1, 2]; let [x, y] = arr; console.log(x); console.log(y); })() #+END_SRC #+RESULTS: 

The output looks like this

 /tmp/babel-13529OHt/js-script-13529MVq:6 let [x, y] = arr; ^ SyntaxError: Unexpected token [ at exports.runInThisContext (vm.js:53:16) at Module._compile (module.js:404:25) at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:5) at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7) at Module.load (module.js:356:32) at Function.Module._load (module.js:311:12) at Function.Module.runMain (module.js:457:10) at /usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:161:27 at Object. (/usr/local/lib/node_modules/babel-cli/lib/_babel-node.js:162:7) at Module._compile (module.js:425:26) 

> Edit: Thanks to @ebpa i've managed to solve it with

npm install -g babel-preset-es2015

This is the output i'm getting after evaluating the default source block, which doesn't have a self executing function wrapper.

 /usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:372 throw new Error("Couldn't find preset " + JSON.stringify(val) + " relative to directory " + JSON.stringify(dirname)); ^ Error: Couldn't find preset "es2015" relative to directory "/tmp/babel-270346ez" at /usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:372:17 at Array.map (native) at OptionManager.resolvePresets (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:364:20) at OptionManager.mergePresets (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:348:10) at OptionManager.mergeOptions (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:307:14) at OptionManager.init (/usr/local/lib/node_modules/babel-cli/node_modules/babel-core/lib/transformation/file/options/option-manager.js:465:10) at compile (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:81:45) at loader (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:126:14) at Object.require.extensions.(anonymous function) [as .js] (/usr/local/lib/node_modules/babel-cli/node_modules/babel-register/lib/node.js:136:7) at Module.load (module.js:356:32) 

Edit: Fire up a terminal and ran babel-node

 > require('babel-preset-es2015'); 

Output

 Error: Cannot find module 'babel-preset-es2015' at Function.Module._resolveFilename (module.js:337:15) at Function.Module._load (module.js:287:25) at Module.require (module.js:366:17) at require (module.js:385:17) at repl:1:1 at Object.exports.runInThisContext (vm.js:54:17) at _eval (/home/johnwind/.nvm/versions/node/v5.0.0/lib/node_modules/babel-cli/lib/_babel-node.js:102:26) at REPLServer.replEval (/home/johnwind/.nvm/versions/node/v5.0.0/lib/node_modules/babel-cli/lib/_babel-node.js:187:14) at bound (domain.js:280:14) at REPLServer.runBound [as eval] (domain.js:293:12) 

Edit: A follow up to getting it up and running

http://rwx.io/blog/2016/03/09/org-with-babel-node-updated/

<br >

Edit: This post gave me some clue to this piece of to puzzle

https://phabricator.babeljs.io/T6723

http://discuss.babeljs.io/t/error-parsing-jsx-with-global-installation-babel-preset-react/59/6

<br >

Edit: Finally got it working by installing a local copy

 $ mkdir local_babel $ cd local_babel $ npm install --save-dev babel-cli $ npm install --save-dev babel-core $ npm install --save-dev babel-preset-es2015 

created a softlink for babel-node

 $ cd /usr/local/bin/ $ sudo ln -s ~/.node_modules/lib/node_modules/babel-cli/bin/babel-node.js org-babel-node 

<br >

Added this to my init.el

 (setenv "NODE_PATH" (concat "/home/johnwind/local_babel/node_modules" ":" (getenv "NODE_PATH") ) ) 

<br > output

 #+BEGIN_SRC js :cmd "org-babel-node --presets es2015" let arr = [1, 2]; let [x, y] = arr; console.log(x); console.log(y); #+END_SRC #+RESULTS: : 1 : 2 : undefined 

<br > For now I have both local and global copy of babel-cli, babel-core, babel-preset-es2015 . Which still couldn't quite wrap my head around this as it's kind of a waste of resources.

But it works.