Refactor stripe session creation flow

.gitignore

@@ -1,2 +1,3 @@
 dist/
 node_modules/
+.env

package-lock.json

@@ -12,6 +12,7 @@
         "@nestjs/common": "^11.0.1",
         "@nestjs/core": "^11.0.1",
         "@nestjs/platform-express": "^11.0.1",
+        "dotenv": "^17.2.3",
         "reflect-metadata": "^0.2.2",
         "rxjs": "^7.8.1",
         "stripe": "^20.0.0",
@@ -4968,9 +4969,9 @@
       }
     },
     "node_modules/dotenv": {
-      "version": "16.6.1",
+      "version": "17.2.3",
-      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.6.1.tgz",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-17.2.3.tgz",
-      "integrity": "sha512-uBq4egWHTcTt33a72vpSG0z3HnPuIl6NqYcTrKEg2azoEyl2hpW0zqlxysq2pK9HlDIHyHyakeYaYnSAwd8bow==",
+      "integrity": "sha512-JVUnt+DUIzu87TABbhPmNfVdBDt18BLOWjMUFJMSi/Qqg7NTYtabbvSNJGOJ7afbRuv9D/lngizHtP7QyLQ+9w==",
       "license": "BSD-2-Clause",
       "engines": {
         "node": ">=12"
@@ -10052,6 +10053,18 @@
         "ieee754": "^1.2.1"
       }
     },
+    "node_modules/typeorm/node_modules/dotenv": {
+      "version": "16.6.1",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-16.6.1.tgz",
+      "integrity": "sha512-uBq4egWHTcTt33a72vpSG0z3HnPuIl6NqYcTrKEg2azoEyl2hpW0zqlxysq2pK9HlDIHyHyakeYaYnSAwd8bow==",
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://dotenvx.com"
+      }
+    },
     "node_modules/typeorm/node_modules/glob": {
       "version": "10.4.5",
       "resolved": "https://registry.npmjs.org/glob/-/glob-10.4.5.tgz",

package.json

@@ -18,6 +18,7 @@
     "@nestjs/common": "^11.0.1",
     "@nestjs/core": "^11.0.1",
     "@nestjs/platform-express": "^11.0.1",
+    "dotenv": "^17.2.3",
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1",
     "stripe": "^20.0.0",

src/access.controller.ts

@@ -1,4 +1,10 @@
-import { Body, Controller, Logger, Post, UnauthorizedException } from '@nestjs/common';
+import {
+  Body,
+  Controller,
+  Logger,
+  Post,
+  UnauthorizedException,
+} from '@nestjs/common';
 import { UserService } from './user.service';
 
 @Controller('/access')
@@ -8,23 +14,29 @@ export class AccessController {
   constructor(private readonly userService: UserService) {}
 
   @Post('/login')
-  public login(@Body("name") name: string, @Body("password") password: string): {userId: number} {
+  public login(
-    this.logger.debug("Received login request");
+    @Body('name') name: string,
+    @Body('password') password: string,
+  ): { userId: number } {
+    this.logger.debug('Received login request');
     const user = this.userService.getUserByName(name);
     if (user.password !== password) {
       throw new UnauthorizedException();
     }
     return {
-      userId: user.id
+      userId: user.id,
     };
   }
 
   @Post('/register')
-  public new(@Body("name") name: string, @Body("password") password: string): {userId: number} {
+  public new(
-    this.logger.debug("Received register request");
+    @Body('name') name: string,
+    @Body('password') password: string,
+  ): { userId: number } {
+    this.logger.debug('Received register request');
     const user = this.userService.createUser(name, password);
     return {
-      userId: user.id
+      userId: user.id,
     };
   }
 }

src/app.module.ts

@@ -3,10 +3,11 @@ import { AccessController } from './access.controller';
 import { UserService } from './user.service';
 import { BuyController } from './buy.controller';
 import { PurchaseService } from './purchase.service';
+import { StripeService } from './stripe.service';
 
 @Module({
   imports: [],
   controllers: [AccessController, BuyController],
-  providers: [UserService, PurchaseService],
+  providers: [UserService, PurchaseService, StripeService],
 })
 export class AppModule {}

src/buy.controller.ts

@@ -1,45 +1,37 @@
-import { Body, Controller, Get, Post, Redirect } from "@nestjs/common";
+import { Body, Controller, Get, Post, Redirect } from '@nestjs/common';
-import Stripe from 'stripe'
+import { PurchaseService } from './purchase.service';
-import { PurchaseService } from "./purchase.service";
+import { UserService } from './user.service';
-import { UserService } from "./user.service";
+import { PurchaseItem } from './dto/purchase-item';
-import { PurchaseItem } from "./dto/purchase-item";
+import { StripeService } from './stripe.service';
 
 @Controller('/buy')
 export class BuyController {
-    private static TEST_KEY = "sk_test_51SVqfTBQui1OXGpt6kgnIuDpbwAqQBZqNoVXkn77UeoxfOMgjC3xFuXCet1h51REAq9XeP72qBDWdXlbaTvxb4yN00YWF6TWFm"
+  constructor(
-    private readonly stripe = new Stripe(BuyController.TEST_KEY)
+    private readonly purchaseService: PurchaseService,
+    private readonly userService: UserService,
+    private readonly stripeService: StripeService
+  ) {}
 
-    constructor(private readonly purchaseService: PurchaseService, private readonly userService: UserService) {}
+  @Post('/start')
+  @Redirect()
+  public async startPurchaseFlow(
+    @Body('userId') userId: number,
+    @Body('quantity') quantity: number,
+  ) {
+    const user = this.userService.getUserById(userId);
+    const purchase = this.purchaseService.recordPurchaseStart(
+      user,
+      PurchaseItem.PAELLA,
+      quantity,
+    );
+    const session = await this.stripeService.createStripeSession(purchase);
+    console.log(session);
+    return { url: session.url };
+  }
 
-    @Post("/start")
+  @Get('/complete')
-    @Redirect()
+  public complete() {}
-    public async getStripeSessionUrl(@Body("userId") userId: number, @Body("quantity") quantity: number) {
-        const user = this.userService.getUserById(userId)
-        const purchase = this.purchaseService.recordPurchaseStart(user, PurchaseItem.PAELLA, quantity)
-        const session = await this.stripe.checkout.sessions.create({
-            line_items: [
-                {
-                    price: purchase.purchasedProduct,
-                    quantity: purchase.purchasedUnits
-                }
-            ],
-            mode: "payment",
-            success_url: "https://localhost:5173/buy/complete",
-            cancel_url: "https://localhost:5173/buy/cancel",
-            payment_method_types: ['card'], 
-        })
-        console.log(session)
 
-        return {url: session.url}
+  @Get('/cancel')
-    }
+  public cancel() {}
-
-    @Get("/complete")
-    public complete() {
-        
-    }
-
-    @Get("/cancel")
-    public cancel() {
-        
-    }
 }

src/dto/purchase-item.ts

@@ -1,4 +1,3 @@
 export enum PurchaseItem {
-    PAELLA = "PAELLA",
+  PAELLA = 'PAELLA',
 }
-

src/dto/purchase-status.ts

@@ -1,6 +1,5 @@
 export enum PurchaseStatus {
-    CREATED = "CREATED",
+  CREATED = 'CREATED',
-    COMPLETED = "COMPLETED",
+  COMPLETED = 'COMPLETED',
-    FAILED = "FAILED",
+  FAILED = 'FAILED',
 }
-

src/dto/purchase.ts

@@ -1,11 +1,11 @@
-import { PurchaseItem } from "./purchase-item";
+import { PurchaseItem } from './purchase-item';
-import { PurchaseStatus } from "./purchase-status";
+import { PurchaseStatus } from './purchase-status';
-import { User } from "./user";
+import { User } from './user';
 
 export class Purchase {
-    id: number;
+  id: number;
-    purchasedBy: User;
+  purchasedBy: User;
-    purchasedProduct: PurchaseItem;
+  purchasedProduct: PurchaseItem;
-    purchasedUnits: number;
+  purchasedUnits: number;
-    status: PurchaseStatus
+  status: PurchaseStatus;
 }

src/main.ts

@@ -1,6 +1,8 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
+import dotenv from 'dotenv'
 
+dotenv.config();
 async function bootstrap() {
   const app = await NestFactory.create(AppModule);
   await app.listen(process.env.PORT ?? 3000);

src/purchase.service.ts

@@ -1,31 +1,37 @@
-import { Injectable, Logger } from "@nestjs/common";
+import { Injectable, Logger } from '@nestjs/common';
-import { Purchase } from "./dto/purchase";
+import { Purchase } from './dto/purchase';
-import { User } from "./dto/user";
+import { User } from './dto/user';
-import { PurchaseItem } from "./dto/purchase-item";
+import { PurchaseItem } from './dto/purchase-item';
-import { PurchaseStatus } from "./dto/purchase-status";
+import { PurchaseStatus } from './dto/purchase-status';
 
 @Injectable()
 export class PurchaseService {
-    private readonly purchases: Purchase[] = [];
+  private readonly purchases: Purchase[] = [];
-    private readonly logger = new Logger(PurchaseService.name);
+  private readonly logger = new Logger(PurchaseService.name);
 
-    constructor() {}
+  constructor() {}
 
-    public recordPurchaseStart(user: User, purchasedItem: PurchaseItem, units: number): Purchase {
+  public recordPurchaseStart(
-        this.logger.debug(`Recording purchase for user ID: ${user.id}`)
+    user: User,
-        const purchase: Purchase = {
+    purchasedItem: PurchaseItem,
-            id: this.purchases.length,
+    units: number,
-            purchasedBy: user,
+  ): Purchase {
-            purchasedProduct: purchasedItem,
+    this.logger.debug(`Recording purchase for user ID: ${user.id}`);
-            purchasedUnits: units,
+    const purchase: Purchase = {
-            status: PurchaseStatus.CREATED
+      id: this.purchases.length,
-        }
+      purchasedBy: user,
-        this.purchases.push(purchase)
+      purchasedProduct: purchasedItem,
-        return purchase;
+      purchasedUnits: units,
-    }
+      status: PurchaseStatus.CREATED,
+    };
+    this.purchases.push(purchase);
+    return purchase;
+  }
 
-    public findPurchasesByUser(userId: number): Purchase[] {
+  public findPurchasesByUser(userId: number): Purchase[] {
-        this.logger.debug(`Searching purchases for user ID: ${userId}`)
+    this.logger.debug(`Searching purchases for user ID: ${userId}`);
-        return this.purchases.filter(purchase => purchase.purchasedBy.id = userId);
+    return this.purchases.filter(
-    }
+      (purchase) => (purchase.purchasedBy.id = userId),
+    );
+  }
 }

src/stripe.service.ts

@@ -0,0 +1,28 @@
+import { Injectable } from '@nestjs/common';
+import { Purchase } from './dto/purchase';
+import Stripe from 'stripe';
+
+@Injectable()
+export class StripeService {
+  private readonly stripe: Stripe;
+
+  constructor() {
+    const stripePrivateKey = process.env.STRIPE_PRIVATE_KEY!;
+    this.stripe = new Stripe(stripePrivateKey);
+  }
+
+  public createStripeSession(purchase: Purchase): Promise<Stripe.Response<Stripe.Checkout.Session>> {
+    return this.stripe.checkout.sessions.create({
+      line_items: [
+        {
+          price: purchase.purchasedProduct,
+          quantity: purchase.purchasedUnits,
+        },
+      ],
+      mode: 'payment',
+      success_url: 'https://localhost:5173/buy/complete',
+      cancel_url: 'https://localhost:5173/buy/cancel',
+      payment_method_types: ['card'],
+    });
+  }
+}

src/user.service.ts

@@ -4,12 +4,12 @@ import { User } from './dto/user';
 @Injectable()
 export class UserService {
   private readonly users: User[] = [];
-  private readonly logger = new Logger(UserService.name)
+  private readonly logger = new Logger(UserService.name);
 
   constructor() {}
 
   public getUserByName(name: string): User {
-    this.logger.debug(`Get user by name: ${name}`)
+    this.logger.debug(`Get user by name: ${name}`);
     const user = this.users.find((u) => u.name === name);
     if (!user) {
       throw new NotFoundException();
@@ -18,7 +18,7 @@ export class UserService {
   }
 
   public getUserById(userId: number): User {
-    this.logger.debug(`Get user by id: ${userId}`)
+    this.logger.debug(`Get user by id: ${userId}`);
     const user = this.users.find((u) => u.id === userId);
     if (!user) {
       throw new NotFoundException();
@@ -34,7 +34,7 @@ export class UserService {
       if (!(e instanceof NotFoundException)) throw e;
     }
 
-    this.logger.debug(`Creating user with name: ${name}`)
+    this.logger.debug(`Creating user with name: ${name}`);
     const user: User = {
       id: this.users.length,
       name,