Validation

[Yamiteru]

• Type

type TInt = Type<"int", number>;

• Assert

const int: Assert<TInt> = (v) => {
  assertType(v, "number");
  assertInt(v);
};

• Composition

const person = object({
  name: string(),
  age: int(min(18), max(99)),
  friends: nullable(array(person))
});

// error since number is not assignable to type person
person(1);

• Value

const $int = value(int);

const double = $int(0, (v) => v * 2);
const doubleUSD = $string("0 USD", (v, { previous }) => {
  const _double = $(double);
  if(v === previous.input) return undefined;
  return `${_double} USD`;
});

• Validate

// valid = false, data = undefined, error = "value 12.5 is not int"
const { valid, data, error } = validate(int, 12.5);

• Composition

const age = int(
  min(0),
  max(99)
);

const zip = string(
  length(5)
);

const email = string(
  min(8),
  regex(emailRegex)
);