Neode with NestJS

A module to connect Neode, Neo4j and NestJS.

npm i neode-nestjs or yarn add neode-nestjs

Variables

.env

If your connection fail check if you are reading your .env settings before start your application You must add env-cmd before your script

{
     "start:dev": "env-cmd nest start --watch"
}

NEO4J_DATABASE=neo4j
NEO4J_USERNAME=neo4j
NEO4J_PASSWORD=your-password
NEO4J_HOST=localhost
NEO4J_PORT=7687
NEO4J_PROTOCOL=neo4j
NEO4J_ENCRYPTION=ENCRYPTION_OFF

---

Main module with .env settings

import { NeodeModule } from 'neode-nestjs';

app.module.ts

@Module({
     imports: [NeodeModule.forRoot(), UserModule],
     controllers: [AppController],
     providers: [],
})
export class AppModule {}

Main module with connection settings

@Module({
 imports: [
  NeodeModule.forRoot (
   { host: 'bolt://localhost', port: 7689, username: 'name', password: '1234' }
 ), UserModule],
     controllers: [UserController],
     providers: [UserService],
})
export class UserModule {}

---

Entities or Schemas

Your schema to inject on module

Important when you import Neode if throw types error you should use import like example bellow.

import * as Neode from 'neode';

Schema

import { SchemaObject } from 'neode';

const UserSchema: SchemaObject = {
     id: {
          type: 'uuid',
          primary: true,
          required: true,
     },
     name: {
          type: 'string',
          required: true,
     },
     email: {
          type: 'string',
          unique: true,
          required: true,
     },
     password: {
          type: 'string',
          required: true,
     },
     avatar: {
          type: 'string',
     },
     isFirstAuth: {
          type: 'boolean',
     },
};

export default UserSchema;

---

Specific module with .env settings

@Module({
     imports: [NeodeModule.forFeature({ User: UserSchema })],
     controllers: [UserController],
     providers: [UserService],
})
export class UserModule {}

Specific module with connection settings

@Module({
 imports: [
  NeodeModule.forFeature (
   { User: UserSchema }, 
   { host: 'bolt://localhost', port: 7689, username: 'name', password: '1234' }
 )],
     controllers: [UserController],
     providers: [UserService],
})
export class UserModule {}

---

User interface

Example User interface

export interface UserInterface {
     id: string;
     name: string;
     email: string;
     password: string;
     avatar: string;
     isFirstAuth: boolean;
}

---

Create user dto

Dto example if you are using rest api. The decorator validation @IsEmail refer to class-validator

export class CreateUserDto implements Partial<UserInterface> {
     @IsNotEmpty()
     avatar!: string;

     @IsEmail()
     @IsNotEmpty()
     email!: string;

     @IsString()
     @IsNotEmpty()
     name!: string;

     @IsNotEmpty()
     @IsString()
     password!: string;
}

Service class

You can get connection by injected Connection. It returns a Neode instance

The word 'User' is the same you have used to inject on { User: UserSchema } if you use same different word as not User you must to use it.

@Injectable()
export class UserService {
     constructor(@Inject('Connection') private readonly neode: Neode) {}

     async createUser(dto: CreateUserDto): Promise<void> {
          // note that on example my interface has id and isFirstAuth attributes, and my Dto not.
          // Generate id
          const id: string = uuid();
          // Set isFirstAuth
          const isFirstAuth: boolean = true;

          await this.neode.merge('User', { ...dto, id, isFirstAuth });
     }

     async getUsers(): Promise<UserInterface[]> {
          const users = await this.neode.all('User');
          return (await users.toJson()) as UserInterface[];
     }
}

References

• Neode
• Neo4J
• NestJS
• Class Validator
• Env Cmd