dkildar / immutable-entity-manager

This initiative enables developers to leverage entities in Node.js projects, whether on the client side or in any other Node.js environment.

Immutable entities manager

This initiative enables developers to leverage entities in Node.js projects, whether on the client side or in any other Node.js environment.

🔨 Installation

npm install immutable-entity-manager

yarn add immutable-entity-manager

🗒️ Usage/Examples

This package is built on the foundation of the manager and builder patterns. Each immutable entity has its own dedicated manager, designed to assist in data parsing. The manager, in turn, yields a builder class responsible for handling various tasks such as processing decorators, applying properties, and more.

This package uses Typescript under-the-hood which means that it generates return type, properties name, etc.

@ImmutableEntity()
class Person {
  readonly firstName!: string
  readonly lastName!: string
  @ImmutableEntityTyped(Date) readonly birthDate!: Date
}

const person = ImmutableEntityManager
    .getUniqueManager(Person)
    .parseFromJson({
        first_name: 'hello',
        last_name: 'world',
        birth_date: '2023-12-15T11:01:22.041Z'
    })
    .build()

expect(person.firstName).toBe('hello')
expect(person.lastName).toBe('world')
expect(person.birthDate).toBeInstanceOf(Date)

📑 API Reference

Decorators

• @ImmutableEntity – mark a class as immutable entity;
• @ImmutableEntityTransient – mark a class property as transient. It means that property won't be handled by manager and builder, also value won't be set;
• @ImmutableEntityDefaultValue(0) – sets the default value for property if JSON data don't have value;
• @ImmutableEntityTyped(Date) – mark a property as typed. Argument could be any class or other one immutable entity. In this case, it will apply immutable entity rules for this property otherwise it will create a new class with value as argument;

Manager

Manager represents the parser of entity.

ImmutableEntityManager
    .getUniqueManager(Person)
    .parseFromJson({
        ...
    })

Builder

Builder represents the standard entity builder pattern. Builder is exported and could be created directly but the best way is using of the manager parsing result object.

const builder = ImmutableEntityManager
    .getUniqueManager(Person)
    .parseFromJson({
        ...
    })

Property setting

Builder allows to set the values for properties. It will override data given by manager in a parsing stage.

• Arguments: propertyName: string, value: any, applyDecorators: boolean. Apply decorators allow to set: should the builder apply this package decorators before setting the value.

builder
    .withProperty('someProperty', someValue)
    .withProperty('someAnotherProperty', someAnotherValue)

Options setting

Builder allow to choose conversion of properties: camel to snake or viceversa. snakeToCamelCase is default.

builder.withOptions({ camelToSnakeCase: true })

🙌 Roadmap

• Add transformation of property before parsing or in withProperty;

• Allow to developers set custom constructor for entity which couldn't be initialized with @ImmutableEntityTyped decorator;

• Add entity cloning;

• Add React helper hooks for managing entities reactively;

• Add different parser sources like Buffer, string etc.;

• Add global singleton managers for each entity;

• Allow to build entities w/o case conversion or with custom conversion function;