Discussion on: Nested Conditional Operators

const main = () => {
    const obj = {
        field2: [1,2,3],
        field3: 'joe'
    }

    result = validateInput(obj)

    result
        .then(success=>console.log('validation was successful'))
        .catch(error=>console.log(`${error}`))
}

const validateInput = ({field1, field2, field3}) => {
    try {
        validateField(exists(field1), 'Missing field1')
        validateField(Array.isArray(field2), 'field 2 is not an Array')
        validateField(isValidType(field3), 'field3 is invalid')

        return Promise.resolve()
    } catch (error) {
        return Promise.reject(error)
    }
}

const validateField = (condition, message) => {
    if (!condition)
        throw new Error(message)
}

//implemented as a stub
const isValidType = field => true

//not sure if there needs to be a distinction between boolean
//fields that are set to false, fields that are set to null or empty string, 
//and fields that simply don't exist in the object
const exists = field => field != undefined

main() //Error: Missing field1