Why is this an issue?

Shared naming conventions allow teams to collaborate efficiently.

This rule raises an issue when a function or a method name does not match a provided regular expression.

For example, with the default regular expression ^[a-z][a-zA-Z0-9]*$, the function:

function DoSomething(){...}  // Noncompliant

should be renamed to

function doSomething(){...}

Exceptions

This rule ignores React Functional Components, JavaScript functions named with a capital letter and returning a React element (JSX syntax).

function Welcome() { // Compliant by exception
  const greeting = 'Hello, World!';

  // ...

  return (
    <div className="Welcome">
      <p>{greeting}</p>
    </div>
  );
}