feat: add auth using jwt

.env.example

@@ -0,0 +1 @@
+JWT_SECRET=

package.json

@@ -14,8 +14,15 @@
 	},
 	"dependencies": {
 		"@nestjs/common": "^10.0.0",
+		"@nestjs/config": "^3.3.0",
 		"@nestjs/core": "^10.0.0",
+		"@nestjs/jwt": "^10.2.0",
+		"@nestjs/passport": "^10.0.3",
 		"@nestjs/platform-express": "^10.0.0",
+		"axios": "^1.7.7",
+		"passport": "^0.7.0",
+		"passport-jwt": "^4.0.1",
+		"passport-oauth2": "^1.8.0",
 		"reflect-metadata": "^0.2.0",
 		"rxjs": "^7.8.1"
 	},
@@ -25,6 +32,7 @@
 		"@nestjs/testing": "^10.0.0",
 		"@types/express": "^5.0.0",
 		"@types/node": "^20.3.1",
+		"@types/passport-oauth2": "^1.4.17",
 		"@types/supertest": "^6.0.0",
 		"@typescript-eslint/eslint-plugin": "^8.0.0",
 		"@typescript-eslint/parser": "^8.0.0",

src/app.controller.ts

@@ -1,12 +1,20 @@
-import { Controller, Get } from "@nestjs/common";
+import { Controller, Get, UseGuards } from "@nestjs/common";
+
 import { AppService } from "./app.service";
+import { AuthGuard } from "./auth/auth.guard";
 
 @Controller()
 export class AppController {
 	constructor(private readonly appService: AppService) {}
 
 	@Get()
-	getHello(): string {
+	getHello() {
+		return this.appService.getHello();
+	}
+
+	@Get("protected")
+	@UseGuards(AuthGuard)
+	getProtectedHello() {
 		return this.appService.getHello();
 	}
 }

src/app.module.ts

@@ -1,9 +1,22 @@
 import { Module } from "@nestjs/common";
+import { ConfigModule } from "@nestjs/config";
+import { JwtModule } from "@nestjs/jwt";
+
 import { AppController } from "./app.controller";
 import { AppService } from "./app.service";
+import { AuthModule } from "./auth/auth.module";
 
 @Module({
-	imports: [],
+	imports: [
+		ConfigModule.forRoot({
+			isGlobal: true,
+		}),
+		JwtModule.register({
+			global: true,
+			secret: process.env.JWT_SECRET,
+		}),
+		AuthModule,
+	],
 	controllers: [AppController],
 	providers: [AppService],
 })

src/app.service.ts

@@ -2,7 +2,9 @@ import { Injectable } from "@nestjs/common";
 
 @Injectable()
 export class AppService {
-	getHello(): string {
-		return "Hello World!";
+	getHello() {
+		return {
+			message: "Hello World!",
+		};
 	}
 }

src/auth/auth.guard.ts

@@ -0,0 +1,35 @@
+import {
+	CanActivate,
+	ExecutionContext,
+	Injectable,
+	UnauthorizedException,
+} from "@nestjs/common";
+import { JwtService } from "@nestjs/jwt";
+import { Request } from "express";
+
+@Injectable()
+export class AuthGuard implements CanActivate {
+	constructor(private jwtService: JwtService) {}
+
+	async canActivate(context: ExecutionContext): Promise<boolean> {
+		const request = context.switchToHttp().getRequest();
+		const token = this.extractTokenFromHeader(request);
+		if (!token) {
+			throw new UnauthorizedException();
+		}
+		try {
+			const payload = await this.jwtService.verifyAsync(token, {
+				secret: process.env.JWT_SECRET,
+			});
+			request["user"] = payload;
+		} catch {
+			throw new UnauthorizedException();
+		}
+		return true;
+	}
+
+	private extractTokenFromHeader(request: Request): string | undefined {
+		const [type, token] = request.headers.authorization?.split(" ") ?? [];
+		return type === "Bearer" ? token : undefined;
+	}
+}

src/auth/auth.module.ts

@@ -0,0 +1,4 @@
+import { Module } from '@nestjs/common';
+
+@Module({})
+export class AuthModule {}

src/main.ts

@@ -3,6 +3,9 @@ import { AppModule } from "./app.module";
 
 async function bootstrap() {
 	const app = await NestFactory.create(AppModule);
+	app.enableCors({
+		origin: "*"
+	});
 	await app.listen(process.env.PORT ?? 3000);
 }
 bootstrap();