feat(database): scaffold core persistence layer and ORM foundation

Author: rabsqueen

src/database/data-source.ts

@@ -0,0 +1,11 @@
+import 'reflect-metadata';
+
+import { DataSource } from 'typeorm';
+
+import { getTypeOrmConfig } from './orm.config';
+
+export const AppDataSource = new DataSource(
+  getTypeOrmConfig(),
+);
+
+export default AppDataSource;

src/database/database.module.ts

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+import { Global, Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+
+import { DatabaseService } from './database.service';
+import { getTypeOrmConfig } from './orm.config';
+
+@Global()
+@Module({
+  imports: [
+    TypeOrmModule.forRootAsync({
+      useFactory: getTypeOrmConfig,
+    }),
+  ],
+  providers: [DatabaseService],
+  exports: [DatabaseService, TypeOrmModule],
+})
+export class DatabaseModule {}

src/database/database.service.ts

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+import {
+  Injectable,
+  Logger,
+  OnApplicationBootstrap,
+  OnApplicationShutdown,
+} from '@nestjs/common';
+import { DataSource } from 'typeorm';
+
+@Injectable()
+export class DatabaseService
+  implements OnApplicationBootstrap, OnApplicationShutdown
+{
+  private readonly logger = new Logger(DatabaseService.name);
+
+  constructor(private readonly dataSource: DataSource) {}
+
+  async onApplicationBootstrap(): Promise<void> {
+    if (!this.dataSource.isInitialized) {
+      await this.dataSource.initialize();
+    }
+
+    this.logger.log(
+      `Database connection established (${this.dataSource.options.type})`,
+    );
+  }
+
+  async onApplicationShutdown(): Promise<void> {
+    if (this.dataSource.isInitialized) {
+      await this.dataSource.destroy();
+
+      this.logger.log('Database connection closed.');
+    }
+  }
+
+  async health() {
+    return {
+      connected: this.dataSource.isInitialized,
+      database: this.dataSource.options.database,
+      type: this.dataSource.options.type,
+    };
+  }
+
+  async execute<T>(
+    callback: (dataSource: DataSource) => Promise<T>,
+  ): Promise<T> {
+    return callback(this.dataSource);
+  }
+
+  get connection(): DataSource {
+    return this.dataSource;
+  }
+}

src/database/orm.config.ts

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+import { TypeOrmModuleOptions } from '@nestjs/typeorm';
+
+export function getTypeOrmConfig(): TypeOrmModuleOptions {
+  return {
+    type: 'postgres',
+
+    host: process.env.DB_HOST,
+
+    port: Number(process.env.DB_PORT ?? 5432),
+
+    username: process.env.DB_USERNAME,
+
+    password: process.env.DB_PASSWORD,
+
+    database: process.env.DB_DATABASE,
+
+    autoLoadEntities: true,
+
+    synchronize: false,
+
+    logging:
+      process.env.NODE_ENV !== 'production',
+
+    ssl:
+      process.env.DB_SSL === 'true'
+        ? {
+            rejectUnauthorized: false,
+          }
+        : false,
+
+    migrations: [
+      'dist/database/migrations/*.js',
+    ],
+
+    migrationsRun: false,
+
+    entities: ['dist/**/*.entity.js'],
+
+    extra: {
+      max: Number(
+        process.env.DB_POOL_SIZE ?? 20,
+      ),
+
+      min: Number(
+        process.env.DB_POOL_MIN ?? 5,
+      ),
+
+      idleTimeoutMillis: Number(
+        process.env.DB_IDLE_TIMEOUT ??
+          30000,
+      ),
+
+      connectionTimeoutMillis:
+        Number(
+          process.env.DB_CONNECTION_TIMEOUT ??
+            5000,
+        ),
+    },
+  };
+}