validation.ai

class User {
    @string(min_len=3, max=20)
    name: str,
    @number(min=18, strict_int=true, strict_float=true)
    age: int,
    @in(["male", "female"])
    gender: str = "male",
}
let u1 = User("Le", 20.0, "male") |err| {
    print("Validate error:", err);
};
// Validate error: { 
//      loc: [name], input: Le, type: validation_error,
//      msg: String length is less than the minimum length of 3 
// }
let u2 = User("Lee", 17, "male") |err| {
    print("Validate error:", err);
};
// Validate error: {
//      loc: [age], input: 17, type: validation_error,
//      msg: Number is less than the minimum value of 18
// }
let u3 = User("Lee", 20, "boy") |err| {
    print("Validate error:", err);
};
// Validate error: {
//      loc: [gender], input: boy, type: validation_error,
//      msg: Value is not in the list of allowed values
// }
let u4 = User("Lee") |err| {
    print("Validate error:", err);
};
// Validate error: {
//      loc: [age], input: nil, type: missing,
//      msg: Field required
// }