no-ignored-return required usage

[David Alberto Adler]

Enforce for a function no-ignored-return

Reproducer

function hello() {
  return 'hi'.lastIndexOf('a')
}

hello()

Expected behavior

it should throw error

The return value of "hello" must be used.eslintsonarjs/no-ignored-return

I want to provide the following feedback.

Ideally it should infer the return value is not used. Alternatively, is there a way to specify hello() return value should be used?

Example

eslint-plugin-sonarjs version: 0.11.0

eslint version: 7.14.0

Node.js version: 14.17.0

**Rule key:**no-ignored-return

[Elena Vilchik]

Hi,

This rule only relies on built-in functions where we are sure there is no side effect, other than returned value. We hardly can be sure about it for user-defined functions.
Also we don't think that making it configurable is a good idea, we can't expect user to maintain it properly also there is no proper naming for functions in JS.