lib/utils/ember.js
function hasDuplicateDependentKeys(callExp) {
  if (!isComputedProp(callExp)) return false;

  const dependentKeys = parseDependentKeys(callExp);
  const uniqueKeys = dependentKeys
    .filter((val, index, self) => self.indexOf(val) === index);

  return uniqueKeys.length !== dependentKeys.length;
}
function hasDuplicateDependentKeys(callExp) {
  if (!isComputedProp(callExp)) return false;

  const dependentKeys = parseDependentKeys(callExp);
  const uniqueKeys = dependentKeys
    .filter((val, index, self) => self.indexOf(val) === index);

  return uniqueKeys.length !== dependentKeys.length;
}
function hasDuplicateDependentKeys ( callExp ) { if ( ! isComputedProp ( callExp ) ) return false ; const dependentKeys = parseDependentKeys ( callExp ) ; const uniqueKeys = dependentKeys . filter ( ( val , index , self ) => self . indexOf ( val ) === index ) ; return uniqueKeys . length !== dependentKeys . length ; }
Checks whether a computed property has duplicate dependent keys.

@param  {CallExpression} callExp Given call expression
@return {Boolean}        Flag whether dependent keys present.
Checks whether a computed property has duplicate dependent keys .