Naming convention for const object keys in ES6

Question

Is there a recommended naming convention for key names within a const object in es6? I haven't been able to find a resource which states if they should be uppercase or lowercase.

const COLOR_CODES = {   BLUE: 1,   RED: 1 }; 

vs

const COLOR_CODES = {   blue: 1,   red: 1 }; 

The examples from this MDN article show both styles, so maybe both are acceptable.

Answer 1

NOTE: be aware that the accepted response has a link to an obsolete Google style guide

This is nice (string literals or integer literals):

const PI = 3.14; const ADDRESS = '10.0.0.1'; 

but...

const myObject = { key: 'value' }; const userSuppliedNumber = getInputNumber() 

Google JavaScript Style Guide says:

Declare all local variables with either const or let. Use const by default, unless a variable needs to be reassigned. The var keyword must not be used.

Every constant is a @const static property or a module-local const declaration, but not all @const static properties and module-local consts are constants. Before choosing constant case, consider whether the field really feels like a deeply immutable constant. For example, if any of that instance's observable state can change, it is almost certainly not a constant. Merely intending to never mutate the object is generally not enough.

JavaScript.info says:

...capital-named constants are only used as aliases for “hard-coded” values.

Answer 2

According to Google it would be all caps. Speaking from experience, most of the other programming languages have all caps so I would suggest using that.

Use NAMES_LIKE_THIS for constant values.

Use @const to indicate a constant (non-overwritable) pointer (a variable or property).

Google javascript guide https://google.github.io/styleguide/javascriptguide.xml