@risotto/value-objects

Table of Contents

- Installing
- Value Objects
- StringValueObject
- NumberValueObject
- UUID
- Enum
- Custom Value Objects
- Primitives
- Exception

Installing

``bash
npm install @risotto/value-objects
`

Once the package is installed, you can import the library using import or require approach:

`js
import { StringValueObject } from '@risotto/value-objects';
`

StringValueObject

Initialize String value object

`js
import { StringValueObject } from '@risotto/value-objects';

export class ProductName extends StringValueObject {}

const name = new ProductName('foo');
console.log(name.value); // foo
`

equals()

`js
const name1 = new ProductName('foo');
const name2 = new ProductName('bar');
const name3 = new ProductName('foo');

console.log(name1.equals(name2)); // false
console.log(name1.equals(name3)); // true
`

NumberValueObject

Initialize Number value object

`js
import { NumberValueObject } from '@risotto/value-objects';

export class ProductStockQuantity extends NumberValueObject {}

const quantity = new ProductStockQuantity(24);
console.log(quantity.value); // 24
`

isBiggerThan()

`js
const number1 = new ProductStockQuantity(4);
const number2 = new ProductStockQuantity(2);

console.log(number1.isBiggerThan(number2)); // true
console.log(number2.isBiggerThan(number1)); // false
`

isLessThan()

`js
const number1 = new ProductStockQuantity(2);
const number2 = new ProductStockQuantity(4);

console.log(number1.isLessThan(number2)); // true
console.log(number2.isLessThan(number1)); // false
`

UUID

Initialize Uuid value object

`js
import { Uuid } from '@risotto/value-objects';

const uuid = new Uuid('d2362e93-8f8e-45ed-8154-28a43f70d551');
console.log(uuid.value); // d2362e93-8f8e-45ed-8154-28a43f70d551
`

random()

`js
import { Uuid } from '@risotto/value-objects';

const random = Uuid.random();
console.log(random.value); // random uuid
`

Enum

Initialize Enum value object

`js
import { EnumValueObject } from '@risotto/value-objects';
import { InvalidArgumentError } from '@risotto/value-objects/exceptions';

enum Status {
IN_STOCK = 'IN_STOCK',
OUT_OF_STOCK = 'OUT_OF_STOCK'
}

export class ProductStatus extends EnumValueObject {
constructor(value: Status) {
super(value, Object.values(Status))
}

// custom implementation from abstract class
protected throwErrorForInvalidValue(value: Status): void {
throw new InvalidArgumentError(The status ${value} is invalid);
}
}
`

usage:

`js
const status = new ProductStatus(Status.IN_STOCK);
console.log(status.value); // IN_STOCK
`

Custom Value Objects

You can create your custom implementations by extending from any of the next classes: StringValueObject, NumberValueObject, EnumValueObject, Uuid, and ValueObject

Primitives

With Primitives type you can get the primitive values of any class that extends from ValueObject abstract class

i.e:

`js
import { Primitives } from "@risotto/value-objects/primitives";

export class Product {
constructor(readonly id: ProductId, readonly name: ProductName) {}

toPrimitives(): Primitives {
return {
id: this.id.value,
name: this.name.value
}
}
}
`

Exception

All exceptions thrown by Value Objects are instance of InvalidArgumentError and imports as follow:

`js
import { InvalidArgumentError } from '@risotto/value-objects/exceptions';
``