database-connector for neo4j

.gitignore

@@ -33,3 +33,6 @@ lerna-debug.log*
 !.vscode/tasks.json
 !.vscode/launch.json
 !.vscode/extensions.json
+
+# Environement
+.env

example.env

@@ -0,0 +1,10 @@
+
+# DO NOT COMMIT THIS FILE!
+# 1. Validate that the .gitignore file includes .env
+# 2. Update the below template with the correct values
+# 3. Rename this file to .env
+
+DB_HOST=database_host_name
+DB_PORT=database_port
+DB_USER=database_user
+DB_PASS=database_password

package-lock.json

@@ -16,7 +16,9 @@
         "@nestjs/graphql": "^12.0.1",
         "@nestjs/platform-express": "^10.0.0",
         "apollo-server-core": "^3.12.0",
+        "dotenv": "^16.3.1",
         "graphql": "^16.6.0",
+        "neo4j-driver": "^5.11.0",
         "reflect-metadata": "^0.1.13",
         "rxjs": "^7.8.1",
         "ts-morph": "^19.0.0"
@@ -3582,7 +3584,6 @@
       "version": "1.5.1",
       "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.5.1.tgz",
       "integrity": "sha512-AKpaYlHn8t4SVbOHCy+b5+KKgvR4vrsD8vbvrbiQJps7fKDTkjkDry6ji0rUJjC0kzbNePLwzxq8iypo41qeWA==",
-      "dev": true,
       "funding": [
         {
           "type": "github",
@@ -4346,6 +4347,17 @@
         "node": ">=6.0.0"
       }
     },
+    "node_modules/dotenv": {
+      "version": "16.3.1",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.3.1.tgz",
+      "integrity": "sha512-IPzF4w4/Rd94bA9imS68tZBaYyBWSCE47V1RGuMrB94iyTOIEwRmVL2x/4An+6mETpLrKJ5hQkB8W4kFAadeIQ==",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://github.com/motdotla/dotenv?sponsor=1"
+      }
+    },
     "node_modules/ee-first": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
@@ -5465,7 +5477,6 @@
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/ieee754/-/ieee754-1.2.1.tgz",
       "integrity": "sha512-dcyqhDvX1C46lXZcVqCpK+FtMRQVdIMN6/Df5js2zouUsqG7I6sFxitIC+7KYK29KdXOLHdu9zL4sFnoVQnqaA==",
-      "dev": true,
       "funding": [
         {
           "type": "github",
@@ -6844,6 +6855,62 @@
       "integrity": "sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==",
       "dev": true
     },
+    "node_modules/neo4j-driver": {
+      "version": "5.11.0",
+      "resolved": "https://registry.npmjs.org/neo4j-driver/-/neo4j-driver-5.11.0.tgz",
+      "integrity": "sha512-2IPKXH9najfKJyczIZ8R15p/oYsb4P+nwp76XRjO46Zl+ssc22+gMe/8FLRYw3tRJYc3b87ikx2s8ZNuseOAxQ==",
+      "dependencies": {
+        "neo4j-driver-bolt-connection": "5.11.0",
+        "neo4j-driver-core": "5.11.0",
+        "rxjs": "^7.8.1"
+      }
+    },
+    "node_modules/neo4j-driver-bolt-connection": {
+      "version": "5.11.0",
+      "resolved": "https://registry.npmjs.org/neo4j-driver-bolt-connection/-/neo4j-driver-bolt-connection-5.11.0.tgz",
+      "integrity": "sha512-jfptm6W/a4CIoip4S/KubxrPIIV3hdOJ8B5t2RtMJwVfup8uJFzRsQLW/ljg7PJdMiE1hHQ94/qcVKd3gCC3og==",
+      "dependencies": {
+        "buffer": "^6.0.3",
+        "neo4j-driver-core": "5.11.0",
+        "string_decoder": "^1.3.0"
+      }
+    },
+    "node_modules/neo4j-driver-bolt-connection/node_modules/buffer": {
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/buffer/-/buffer-6.0.3.tgz",
+      "integrity": "sha512-FTiCpNxtwiZZHEZbcbTIcZjERVICn9yq/pDFkTl95/AxzD1naBctN7YO68riM/gLSDY7sdrMby8hofADYuuqOA==",
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/feross"
+        },
+        {
+          "type": "patreon",
+          "url": "https://www.patreon.com/feross"
+        },
+        {
+          "type": "consulting",
+          "url": "https://feross.org/support"
+        }
+      ],
+      "dependencies": {
+        "base64-js": "^1.3.1",
+        "ieee754": "^1.2.1"
+      }
+    },
+    "node_modules/neo4j-driver-bolt-connection/node_modules/string_decoder": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/string_decoder/-/string_decoder-1.3.0.tgz",
+      "integrity": "sha512-hkRX8U1WjJFd8LsDJ2yQ/wWWxaopEsABU1XfkM8A+j0+85JAGppt16cr1Whg6KIbb4okU6Mql6BOj+uup/wKeA==",
+      "dependencies": {
+        "safe-buffer": "~5.2.0"
+      }
+    },
+    "node_modules/neo4j-driver-core": {
+      "version": "5.11.0",
+      "resolved": "https://registry.npmjs.org/neo4j-driver-core/-/neo4j-driver-core-5.11.0.tgz",
+      "integrity": "sha512-HIZrX1wIkwb1BlXtDk0thbyzYrlDKQK9PuzcgeKF9/fTORxr5K39kdIiwVi3gkoGOcFCSoBu+fTnlnav1BcgRg=="
+    },
     "node_modules/node-abort-controller": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/node-abort-controller/-/node-abort-controller-3.1.1.tgz",

package.json

@@ -27,7 +27,9 @@
     "@nestjs/graphql": "^12.0.1",
     "@nestjs/platform-express": "^10.0.0",
     "apollo-server-core": "^3.12.0",
+    "dotenv": "^16.3.1",
     "graphql": "^16.6.0",
+    "neo4j-driver": "^5.11.0",
     "reflect-metadata": "^0.1.13",
     "rxjs": "^7.8.1",
     "ts-morph": "^19.0.0"

src/app.module.ts

@@ -1,4 +1,5 @@
-import { Module, Post } from '@nestjs/common';
+import 'dotenv/config';
+import { Injectable, Logger, Module, OnModuleDestroy, OnModuleInit } from '@nestjs/common';
 import { AppController } from './app.controller';
 import { AppService } from './app.service';
 import { GraphQLModule } from '@nestjs/graphql';
@@ -8,6 +9,41 @@ import { MemberResolver } from './services/reputation/components/member/member.r
 import { PostResolver } from './services/reputation/components/post/post.resolver';
 import { CitationsResolver } from './services/reputation/components/citation/citation.resolver';
 
+import { DatabaseConnector } from './util/database-connector';
+import { MemberRepository } from './services/reputation/components/member/member.repository';
+const dbConnector = new DatabaseConnector(new Logger('DatabaseConnector'));
+
+@Injectable()
+export class StartupService implements OnModuleInit {
+  async onModuleInit() {
+
+    const testSuite = process.env.TEST_SUITE;
+    if (testSuite?.toLowerCase().includes("integration")) return;
+
+    const host = process.env.DB_HOST;
+    const port = process.env.DB_PORT;
+    const user = process.env.DB_USER;
+    const pass = process.env.DB_PASS;
+
+    if (!host) throw new Error('Missing environment variable, DB_HOST');
+    if (!port) throw new Error('Missing environment variable, DB_PORT');
+    if (!user) throw new Error('Missing environment variable, DB_USER');
+    if (!pass) throw new Error('Missing environment variable, DB_PASSWORD');
+
+    const options = {host, port, user, pass};
+    await dbConnector.connect(options, [
+      MemberRepository
+    ]);
+  }
+}
+
+@Injectable()
+export class ShutdownService implements OnModuleDestroy {
+  async onModuleDestroy() {
+    await dbConnector.disconnect();
+  }
+}
+
 @Module({
   imports: [
     GraphQLModule.forRoot<ApolloDriverConfig>({
@@ -19,6 +55,14 @@ import { CitationsResolver } from './services/reputation/components/citation/cit
     }),
   ],
   controllers: [AppController],
-  providers: [AppService, MemberResolver, PostResolver, CitationsResolver],
+  providers: [
+    AppService,
+    StartupService,
+    ShutdownService,
+    MemberResolver,
+    PostResolver,
+    CitationsResolver
+  ],
 })
+
 export class AppModule {}

src/services/reputation/components/citation/citation.spec.ts

@@ -110,6 +110,7 @@ describe('Rep Service Citation - Unit Tests', () => {
 
 describe ('Rep Service Citation - Integration Tests', () => {
 
+    process.env.TEST_SUITE = "Rep Service Citation - Integration Tests";
     let testServer: ApolloTestServer;
 
     let createUser1 = `createMember(id: "testingUser1") { id }`;

src/services/reputation/components/member/member.repository.ts

@@ -0,0 +1,23 @@
+import { DatabaseConnector, Neo4jRepo } from "src/util/database-connector"
+
+
+export class MemberRepository implements Neo4jRepo {
+
+    private static instance: MemberRepository;
+    private static connector: DatabaseConnector;
+
+    private constructor() { }
+
+    public getInstance() { return MemberRepository.getInstance(); }
+    public static getInstance() {
+        if (!MemberRepository.instance) MemberRepository.instance = new MemberRepository();
+        return MemberRepository.instance;
+    }
+    
+    public setConnector(connector: DatabaseConnector) { MemberRepository.setConnector(connector); }
+    public static setConnector(connector: DatabaseConnector) {
+        MemberRepository.connector = connector;
+    }
+
+    
+}

src/services/reputation/components/member/member.spec.ts

@@ -76,6 +76,7 @@ describe('Rep Service Member - Unit Tests', () => {
 
 describe('Rep Service Member - Integration Tests', () => {
 
+    process.env.TEST_SUITE = "Rep Service Member - Integration Tests";
     let testServer: ApolloTestServer;
 
     let createUser1 = `createMember(id: "testingUser1") { id }`;

src/services/reputation/components/post/post.spec.ts

@@ -170,6 +170,7 @@ describe('Rep Service Post - Unit Tests', () => {
 
 describe('Rep Service Post - Integration Tests', () => {
 
+    process.env.TEST_SUITE = "Rep Service Post - Integration Tests";
     let testServer: ApolloTestServer;
 
     let createUser1 = `createMember(id: "testingUser1") { id }`;

src/util/database-connector.ts

@@ -0,0 +1,59 @@
+
+import neo4j, { Driver } from 'neo4j-driver';
+import { Logger } from '@nestjs/common';
+
+export interface DBOptions {
+    host: string;
+    port: string;
+    user: string;
+    pass: string;
+}
+
+export interface Neo4jRepo {
+    getInstance(): Neo4jRepo;
+    setConnector(connector: DatabaseConnector): void
+}
+
+export class DatabaseConnector {
+
+    private driver: Driver;
+    private logger: Logger
+
+    constructor(logger: Logger) { 
+        this.logger = logger;
+    }
+
+    async connect(options: DBOptions, repos: Neo4jRepo[]) {
+        const connectionString = `neo4j+s://${options.host}:${options.port}`;
+        this.logger.log(`Connection: ${connectionString}`);
+        const authentication = neo4j.auth.basic(options.user, options.pass);
+        try {
+            this.driver = neo4j.driver(connectionString, authentication);
+            const info = await this.driver.getServerInfo();
+            if (!info) throw new Error('Unable to retrieve database info');
+            this.logger.log(`Successfully connected to ${info.agent}`);
+            for (const repo of repos) {
+                this.logger.log(`Attaching to ${(<any>repo).name}`);
+                repo.getInstance().setConnector(this);
+            }
+        } catch(error) {
+            this.logger.error(`Failed to connect to Database - ${error.message}`);
+            throw error;
+        }
+    }
+
+    async disconnect() {
+        this.logger.log('Closing database connection...');
+        if (this.driver) await this.driver.close();
+    }
+
+    async runQuery(query: string, parameters: any = {}) {
+        const session = this.driver.session();
+        try {
+            const result = await session.writeTransaction(tx => tx.run(query, parameters));
+            return result.records;
+        } finally {
+            session.close();
+        }
+    }
+}