findDuplicatedObjectKeyValues.js

const findDuplicatedObjectKeyValues = (obj) => {
  const propertyKeys = Object.keys(obj)
  return propertyKeys.reduce((state, propertyKey, index) => {
    const propertyValue = obj[propertyKey]
    if (state.propertyValues.includes(propertyValue)) {
      state.duplicatedValueKeys = [...state.duplicatedValueKeys, propertyKey]
    }
    state.propertyValues = [...state.propertyValues, propertyValue]
    if (index === propertyKeys.length - 1) return state.duplicatedValueKeys
    return state
  }, { propertyValues: [], duplicatedValueKeys: [] })
}

module.exports = findDuplicatedObjectKeyValues