How to use ES6 computed property names in node / iojs?

Question

I am trying to write a tool that takes a CSV and dynamically generates a definition based on the header row?

For example, a CSV with:

Title(STRING), Description(TEXT)
Title Example, Description Example
...

the Sequelize docs specify, for example:

var Entry = sequelize.define('Entry', {
  title: Sequelize.STRING,
  description: Sequelize.TEXT
})

How could I write this definition so that it could be dynamically defined - so that title and the data type Sequelize.STRING could be dynamically generated based on the CSV header row?

---

EDIT

Ok, after some research, I think the obvious question is "How to use variable names as dynamic key names in object literal" and has been answered several times.

As a result, it is simple to write this in bracket notation so:

var definitionObj = {}
definitionObj['title'] = sequelize.STRING;
definitionObj['description'] = sequelize.TEXT;

var Entry = sequelize.define('Entry', definitionObj);

However, then my question now is how do I use ES6 Computed Property Names in node ? I'm using node 0.12.2 which I thought had ES6 support, and even with the --harmony flag, this simple code fails:

var Entry = sequelize.define('Entry', {
  ['title']: Sequelize.STRING,
  ['description']: Sequelize.TEXT
});

with SyntaxError: Unexpected token [

Is the only option really to go to with io.js ?

EDIT 2

Actually this syntax still fails even with iojs, so I must be doing something wrong?

Answer 1

In current Node release > 4.x you have some support for ES6. Status can be found in documentation: https://nodejs.org/en/docs/es6/

What you are looking for is called

Computed (dynamic) property names

and it is fully supported now. Details can be found here: https://github.com/lukehoban/es6features#enhanced-object-literals

Usage:

var obj = {
    // Computed (dynamic) property names
    [ 'prop_' + (() => 42)() ]: 42
};

Will produce object: {prop_42: 42}

Answer 2

The ECMAScript 6 compatibility table shows that neither Node nor io.js currently have support for computed properties. The data is under object literal extensions > computed properties .

Answer 3

Now can use it in iojs v3.0

Changelog https://github.com/nodejs/io.js/blob/master/CHANGELOG.md#user-content-notable-changes