chore: CM-1300 Test DB Connection In Health Check (#115)

backend/src/app.controller.spec.ts

@@ -1,14 +1,15 @@
 import { Test, TestingModule } from "@nestjs/testing";
 import { AppController } from "./app.controller";
 import { AppService } from "./app.service";
+import { PrismaService } from "nestjs-prisma";
 
 describe("AppController", () => {
   let appController: AppController;
 
   beforeEach(async () => {
     const app: TestingModule = await Test.createTestingModule({
       controllers: [AppController],
-      providers: [AppService],
+      providers: [AppService, PrismaService],
     }).compile();
 
     appController = app.get<AppController>(AppController);

backend/src/app.controller.ts

@@ -1,4 +1,4 @@
-import { Controller, Get } from "@nestjs/common";
+import { Controller, Get, HttpException } from "@nestjs/common";
 import { AppService } from "./app.service";
 import { Public } from "./auth/decorators/public.decorator";
 import { ApiTags } from "@nestjs/swagger";
@@ -8,6 +8,14 @@ import { ApiTags } from "@nestjs/swagger";
 export class AppController {
   constructor(private readonly appService: AppService) {}
 
+  @Get()
+  @Public()
+  async getDBHealthCheck(): Promise<string> {
+    const result = await this.appService.getDBHealthCheck();
+    if (result === "Success") {
+      return Promise.resolve(result);
+    } else throw new HttpException("Unable to connect to database", 503);
+  }
   @Get()
   @Public()
   getHello(): string {

backend/src/app.service.ts

@@ -1,8 +1,20 @@
 import { Injectable } from "@nestjs/common";
+import { PrismaService } from "nestjs-prisma";
 
 @Injectable()
 export class AppService {
+  constructor(private readonly prisma: PrismaService) {}
+
   getHello(): string {
     return "Hello from Emerald!";
   }
+
+  async getDBHealthCheck(): Promise<string> {
+    try {
+      await this.prisma.$queryRaw`SELECT 1`;
+      return "Success";
+    } catch (error) {
+      return "Failure";
+    }
+  }
 }