Validators

These are small functions that take in a value and return a ValidationResult. These are meant to be small reusable functions that are joined together to build up complex validation logic.

Base validators

There are a few validators that are used to build up complex validations such as:

multiValidation

Takes a list of validators, these wil be run in order against the value passed to this validator and on the first failure, return the validationResult.

multiValidation example

const validator = multiValidation(minLength(2), maxLength(100));
const isValidResult = validator(anyObject);

separateValidation

Takes in different validators based on the AppType. Use this to run different operations on the UI, API or even from the DataGenerator.

separateValidation example

const validator = separateValidation({
    Api: noValidation,
    UI: validateForEach(notNull('You need to upload an image')),
});
const isValidResult = validator(anyObject);

validateForEach

For each item in the array of values passed to this validator, run the supplied validator

validateForEach example

const validator = validateForEach(
    minLength(1),   
    // For each item in the array, the above validator will run.
    // In this case, checking if the length is greater than 1
),
const isValidResult = validator(['test', 'test2'. '3']);

validateObj

This function takes in a data object to be validated and an object that defines how to validate each property in the data object.

validateObj example

const data: BuilderDto = { ... }
const validationObj: IFormDtoMeta<BuilderDto> = { ... }
const arrayOfValidResults = validateObj({
    data: data;
    validationObj: validationObj
}),

Custom validators

There are quite a few examples in the src/validation folder but the main idea is that your validator should be a function that takes a value of type T and returns a ValidationResult such as:

const myValidator = (value: T): ValidationResult => {
    const randomNum = Math.random() * 10;
    if (randomNum < 5) {
        return { isValid: false, errorMessage: 'Oops, number too small' };
    }

    return { isValid: true };
}