bailer

A lightweight validation library. Inspired by leonardoborges's bouncer for Clojure.

Setup

npm install bailer

Usage

Built-in validators are:

• bailer.validations.required Validates when not null or undefined
• bailer.validations.email Check email format via a regexp
• bailer.validations.number Validates when typeof returns "number"
• bailer.validations.string Validates when typeof returns "string"
• bailer.validations.object Validates when typeof returns "object". Arrays are objects.

You can create your own (see here).

var b = require('bailer'),
    v = b.validations;
 
// Define a dummy object.
var person = {name: "John", age: 20,
              corporation: '',
              email: "[e-mail]"};
 
// Check if it matches the schema.
b.validate(person, {
  name: [v.required],
  age: [v.required],
  email: [v.email]
});
 
// Every validations passed.
// Result:
null

Errors

b.validate(person, {
  name: [b.required],
  corporation: [b.required],
  firstname: [b.required]
});
 
// Uh-oh. The person object object doesn't have a truthy corporation
// (it is empty) or firstname (it is undefined).
// Result:
{corporation: ["corporation must be present"],
 firstname: ["firstname must be present"]}

You can use a custom message.

b.validate(person, {
  corporation: [b.required, "What! You don't work for a corporation?!"]
});
// which results in:
{corporation: ["What! You don't work for a corporation?!"]}

Custom validators

A custom validator is a function with this signature:

function customValidator(obj, attributeName) {
  // Do your stuff here
  // ...
  var correctResult = obj[attributeName].length > 3;
 
  // If the provided value is valid, return null.
  // Otherwise, return a description.
  return correctResult ? null : "".concat(attributename, " should contains at least 3 elements");
}