Entity Parameter

This library provides opinionated helper types for entity construction in any ORM.

• EntityParameter<T>

  • Removes fields with function type
    • Methods are not persisted in the database.
  • Adds optional modifier to nullable fields.
    • So that they can be omitted on object creation.

• EntityParameterStrict<T>

  • Like EntityParameter<T> but removes all optional modifiers.
    • Those are most likely used by relations that may not be loaded for a request, but must be given as a parameter in this case.

Installation

• npm i entity-parameter
• yarn add entity-parameter

Note: strictNullChecks must be enabled for this library to work properly.

Usage

import { EntityParameter, EntityParameterStrict } from "./src"

class User {
    private id?: string

    public name: string

    // This property will be optional in the parameter.
    public address: string | null

    // Relations are assumed to be possibly undefined as they must be loaded explicit with find options.
    public friend?: User

    constructor(params: EntityParameter<User>) {
        this.name = params.name
        this.address = params.address || null
        this.friends = params.friends
    }

    public static strictCreate(params: EntityParameterStrict<User>) {
        return new User(params)
    }

    public getId(){
        return this.id
    }
}

// Error: name is missing.
new User({})

// `address` and `friends` are handled as optional.
new User({
    name: "Rolf"
})

new User({
    name: "Rolf",
    address: "Somewhere",
})

// Minimal example for strict parameter.
User.strictCreate({
    name: "Rolf",
    friend: new User({name: "Hauke"}),
})