okay

gleam add okay@1

import okay

pub type User {
  User(id: Int, name: String, age: Int)
}

pub fn main() {
  let user = User(id: 1, name: "John", age: 20)

  let assert Ok(_) = okay.new()
  |> okay.field("age", okay.is_gt(user.age, 18))
  |> okay.field("name", okay.is_longer(user.name, 1))
  |> okay.run()

  let assert Error(validator) =
    okay.new()
    |> okay.field("age", okay.is_gt(user.age, 30))
    |> okay.field("name", okay.is_longer(user.name, 5))
    |> okay.run()

  let assert [first, second] = validator.failures
  io.debug(first) // ValidationError("age", IsGreaterFailure(value: 20, expected: 30))
  io.debug(second) // ValidationError("name", IsLongerFailure(value: "John", actual: 4, expected: 5))
}

Further documentation can be found at https://hexdocs.pm/okay.

Development

gleam test  # Run the tests