feat: add factory for seed

docs/database.md

@@ -14,6 +14,7 @@ In NestJS Boilerplate uses [TypeORM](https://www.npmjs.com/package/typeorm) and
 - [Seeding](#seeding)
   - [Creating seeds](#creating-seeds)
   - [Run seed](#run-seed)
+  - [Factory and Faker](#factory-and-faker)
 - [Performance optimization](#performance-optimization)
   - [Indexes and Foreign Keys](#indexes-and-foreign-keys)
   - [Max connections](#max-connections)
@@ -90,6 +91,112 @@ npm run schema:drop
 npm run seed:run
 ```
 
+### Factory and Faker
+
+1. Install faker:
+
+    ```bash
+    npm i --save-dev @faker-js/faker
+    ```
+
+1. Create `src/database/seeds/user/user.factory.ts`:
+
+    ```ts
+    import { faker } from '@faker-js/faker';
+    import { RoleEnum } from 'src/roles/roles.enum';
+    import { StatusEnum } from 'src/statuses/statuses.enum';
+    import { Injectable } from '@nestjs/common';
+    import { InjectRepository } from '@nestjs/typeorm';
+    import { Repository } from 'typeorm';
+    import { Role } from 'src/roles/entities/role.entity';
+    import { Status } from 'src/statuses/entities/status.entity';
+    import { User } from 'src/users/entities/user.entity';
+
+    @Injectable()
+    export class UserFactory {
+      constructor(
+        @InjectRepository(User)
+        private repositoryUser: Repository<User>,
+        @InjectRepository(Role)
+        private repositoryRole: Repository<Role>,
+        @InjectRepository(Status)
+        private repositoryStatus: Repository<Status>,
+      ) {}
+
+      createRandomUser() {
+        // Need for saving "this" context
+        return () => {
+          return this.repositoryUser.create({
+            firstName: faker.person.firstName(),
+            lastName: faker.person.lastName(),
+            email: faker.internet.email(),
+            password: faker.internet.password(),
+            role: this.repositoryRole.create({
+              id: RoleEnum.user,
+              name: 'User',
+            }),
+            status: this.repositoryStatus.create({
+              id: StatusEnum.active,
+              name: 'Active',
+            }),
+          });
+        };
+      }
+    }
+    ```
+
+1. Make changes in `src/database/seeds/user/user-seed.service.ts`:
+
+    ```ts
+    // Some code here...
+    import { UserFactory } from './user.factory';
+    import { faker } from '@faker-js/faker';
+
+    @Injectable()
+    export class UserSeedService {
+      constructor(
+        // Some code here...
+        private userFactory: UserFactory,
+      ) {}
+
+      async run() {
+        // Some code here...
+
+        await this.repository.save(
+          faker.helpers.multiple(this.userFactory.createRandomUser(), {
+            count: 5,
+          }),
+        );
+      }
+    }
+    ```
+
+1. Make changes in `src/database/seeds/user/user-seed.module.ts`:
+
+    ```ts
+    import { Module } from '@nestjs/common';
+    import { TypeOrmModule } from '@nestjs/typeorm';
+    import { User } from 'src/users/entities/user.entity';
+    import { UserSeedService } from './user-seed.service';
+    import { UserFactory } from './user.factory';
+    import { Role } from 'src/roles/entities/role.entity';
+    import { Status } from 'src/statuses/entities/status.entity';
+
+    @Module({
+      imports: [TypeOrmModule.forFeature([User, Role, Status])],
+      providers: [UserSeedService, UserFactory],
+      exports: [UserSeedService, UserFactory],
+    })
+    export class UserSeedModule {}
+
+    ```
+
+1. Run seed:
+
+    ```bash
+    npm run seed:run
+    ```
+
 ---
 
 ## Performance optimization