JS Seeder

This package provides you a simple interface and a class, useful to create dummy data starting from a TypeScript interface or a JS object

This package depends on Faker.js

I would recommend using TypeScript to benefit of all of his type checking, as there are a few generic types over here

The Seeder Class

The Seeder class provides a single static method, which is .run, providing three different parameters (first is mandatory, others are optional)

class Seeder {
    static run<T>(seeder: (new () => ISeeder<T>), howMany: number = 1, attributes: T | null = null): Array<T> {
        const seed = new seeder();
        return Array.from(Array(howMany).keys()).map(() => seed.item(attributes))
    }
}

The ISeed Interface

The ISeed generic interface is very basic, providing a single method called .item, whose declaration shows up like this

interface ISeeder<T> {
    item(attributes: T | null): T
}

Creating a new seeder

To extend the Seeder's functionality the process is pretty simple, just create a class which implements the ISeed interface.

For example

import * as faker from "faker";
import ISeeder from "../../src/interfaces";
 
interface ITestSeed {
    id?: string
    name?: string
}
 
class TestSeeder implements ISeeder<ITestSeed> {
 
    item(attributes: ITestSeed | null = null): ITestSeed {
        const defaultValues: ITestSeed = {
            id: faker.random.uuid(),
            name: faker.company.companyName()
        };
 
        return {
            ...defaultValues,
            ...attributes
        };
    }
}
 
export default TestSeeder