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no-extraneous-class

Forbids the use of classes as namespaces.

This rule warns when a class is accidentally used as a namespace.

Rule Details​

From TSLint’s docs:

Users who come from a Java-style OO language may wrap their utility functions in an extra class, instead of putting them at the top level.

Examples of code for this rule:

class EmptyClass {}

class ConstructorOnly {
  constructor() {
    foo();
  }
}

// Use an object instead:
class StaticOnly {
  static version = 42;
  static hello() {
    console.log('Hello, world!');
  }
}

Options​

This rule accepts a single object option.

type Options = {
  // allow extraneous classes if they only contain a constructor
  allowConstructorOnly?: boolean;
  // allow extraneous classes if they have no body (i.e. are empty)
  allowEmpty?: boolean;
  // allow extraneous classes if they only contain static members
  allowStaticOnly?: boolean;
  // allow extraneous classes if they have a decorator
  allowWithDecorator?: boolean;
};

const defaultOptions: Options = {
  allowConstructorOnly: false,
  allowEmpty: false,
  allowStaticOnly: false,
  allowWithDecorator: false,
};

When Not To Use It​

You can disable this rule if you don’t have anyone who would make these kinds of mistakes on your team or if you use classes as namespaces.

no-unnecessary-class from TSLint

Attributes​

  • Configs:
    • ✅ Recommended
    • 🔒 Strict
  • 🔧 Fixable
  • 💭 Requires type information