Create factories for your TypeORM entities. Useful for NestJS applications
The library allows you to create factories for your entities. Useful when unit-testing your NestJS project.
Library using faker.js for provide fake-data in you factories.
Library has peer dependecy for faker and faker-types libraries, but make sure you have them installed. If you want take help about functions in your IDE, just install @types/faker and faker
libraries for yourself.
Install library:
yarn add typeorm-factories
or npm install typeorm-factories
Library can find factory file everywhere in project folder. But could be better if you can create folder for them:
Create folder in project root: mkdir factories
Create your first factory:
import * as Faker from 'faker';
import { define } from 'typeorm-factories';
import { Task } from '../src/tasks/task.entity';
define(Task, (faker: typeof Faker) => {
const task = new Task();
task.id = faker.random.uuid();
task.title = faker.lorem.word();
return task;
});
Here we have factory for Task
entity. Entity has this interface:
@Entity({ name: 'tasks' })
export class Task {
@PrimaryGeneratedColumn('uuid')
id: string;
@Column()
title: string;
}
Use it everywhere:
In my case i wanted to create unit-testing of my project without database hitting. Just test it on mock data. How?
Look at my test file for my tasks controller in project:
For first we need to create mockFactory
for repositories. Place this code everywhere you want:
export type MockType<T> = {
[P in keyof T]: jest.Mock<{}>;
};
// @ts-ignore
export const repositoryMockFactory: () => MockType<Repository<any>> = jest.fn(() => ({
findOne: jest.fn(entity => entity),
findOneOrFail: jest.fn(entity => entity),
// there u can implement another functions of your repositories
}));
And lookup to code of test file for my controller
describe('TasksController', () => {
let controller: TasksController;
let repository: MockType<Repository<Task>>;
beforeEach(async () => {
const module = await Test.createTestingModule({
imports: [FactoryModule],
controllers: [TasksController],
providers: [
TasksService,
{ provide: getRepositoryToken(Task), useFactory: repositoryMockFactory },
],
}).compile();
await module.init(); // we are need to wait for module creating, but we inject our factory module to testing module
controller = module.get<TasksController>(TasksController);
repository = module.get(getRepositoryToken(Task));
});
describe('getOne', () => {
it('should return entity', async () => {
const task = await factory(Task).make();
repository.findOneOrFail.mockReturnValue(task);
expect(await repository.findOneOrFail(task.id)).toEqual(task);
expect(repository.findOneOrFail).toBeCalledWith(task.id);
})
})
});
As you can see, we are create entity by factory via factory()
function.
After call this we have object of type EntityFactory
.
EnityFactory
provide 3 functions:
map(callback)
- callback will be called for every item in array or solo item when we call make
or makeMany
functions.makeMany(count, params)
- create many objects of your entity. Override default params in original object by passed params from variable.make(params)
- create one one entity object and override. About params see above.Detailed instructions for use in development. I have not told even half of all the possibilities of this library. If you have a question about the library’s work, you can create Issue. If you have a desire to help me and make the documentation better, contact me. I have some problems with the narration and I think there are people who do it better than me.