How to check if a field of 'type' is undefined in TypeScript?

Question

I have created a type in TypeScript which is a bit complex (has objects and maps within it).

Is there a way to check if this type has any undefined value or should I go through every part of it to check if it is undefined?

Would typeof be of service in such case?

Answer 1

I have create a recursive function to check an object and its attributes even if it has a nested object and return a boolean

function checkObjectsForUndefined(myObject:object | undefined):boolean
{ 

    if(myObject === undefined)
        return true;

    let result = false;

    let nestedObjectFlag = false;

    let attributes = Object.values(myObject);

    for(let i = 0;i<attributes.length;i++)
    {
        if(attributes[i] instanceof Object)
        {
            nestedObjectFlag = true;

            result = result || checkObjectsForUndefined(attributes[i])
        }

        else
        {
            if(!attributes[i])
                result = true; 
        }
    }

    if(nestedObjectFlag)
        return result;
    else
        return Object.values(myObject).some((value) => !value)
}

Answer 2

You can use a validation library for that.

check out class-validator if you want to use classes

or something like Joi if you want to work with plain objects.