Rule for allowing upper camel case only in Class names and constructor functions (that require new)

[mugli]

I'd like to setup eslint so that I can:

• Use lower camel case for all variable names (myImportedModule, myObject).
• Except:
  • Use upper camel case only for class and constructor function names (MyClass), and nowhere else.
  • Allow all upper snake cases for constants (MY_CONSTANT). This is already covered by camelcase rule.

I have tried:

new-cap: [2, {newIsCap: true, capIsNew: true, properties: true}]

But capIsNew option here only works on function names, not on other variables/object names. For example,

// Expecting lint error: MyLogger has to be lower camel-case (myLogger)
// but it works
const MyLogger = require('my-logger'); 
MyLogger.log('...');

I've also considered id-match, but it doesn't distinguish between identifier types (classes/constructors vs other variables). I cannot totally disable upper camel case names.

Can it be done?

[not-an-aardvark]

Does the camelcase rule do what you're looking for?

[mugli]

No. camelcase doesn't care if the first letter is upper or lower. It just looks for underscores (_) in identifier names (with the exception of all cap constants).

[platinumazure]

id-match is close except that its pattern applies to all identifiers. Could it be expanded to allow an object-based configuration for constructors, functions, identifiers, and properties, each possibly with a different pattern?

[alberto]

Closing this issue as it looks like the question has been answered. Please feel free to visit us in the ESLint Gitter if you have any other issues!

[ratracegrad]

Saw this was closed and wondering what is the correct setting if you are getting new-cap error messages for creation of class in a Polymer 2 app? I have this line which generates 2 new-cap error messages:
class ShopView extends ReduxMixin(Polymer.Element)

I have this rule:
"new-cap": ["error", { "capIsNewExceptions": ["Polymer", "PolymerRedux"] }],