Why is this an issue?

While the ternary operator is pleasingly compact, its use can make code more difficult to read. It should therefore be avoided in favor of the more verbose if/else structure.

Noncompliant code example

function foo(a) {
  var b = (a === 'A') ? 'is A' : 'is not A'; // Noncompliant
  // ...
}

Compliant solution

function foo(a) {
  var b;
  if (a === 'A') {
    b = 'is A';
  }
  else {
    b = 'is not A';
  }
  // ...
}