adding routes and service logic to url-shortener

package-lock.json

@@ -13,7 +13,8 @@
         "@nestjs/core": "^10.0.0",
         "@nestjs/platform-express": "^10.0.0",
         "reflect-metadata": "^0.1.13",
-        "rxjs": "^7.8.1"
+        "rxjs": "^7.8.1",
+        "shortid": "^2.2.16"
       },
       "devDependencies": {
         "@nestjs/cli": "^10.0.0",
@@ -22,6 +23,7 @@
         "@types/express": "^4.17.17",
         "@types/jest": "^29.5.2",
         "@types/node": "^20.3.1",
+        "@types/shortid": "^0.0.32",
         "@types/supertest": "^2.0.12",
         "@typescript-eslint/eslint-plugin": "^5.59.11",
         "@typescript-eslint/parser": "^5.59.11",
@@ -2122,6 +2124,12 @@
         "@types/node": "*"
       }
     },
+    "node_modules/@types/shortid": {
+      "version": "0.0.32",
+      "resolved": "https://registry.npmjs.org/@types/shortid/-/shortid-0.0.32.tgz",
+      "integrity": "sha512-LwWF89yy6Ol8abraYbVedIKzMlgJCTx8zm40yx9t0ZPOJaVR0OmSO4zRRAKfyOJtCwZrEBmhueZX8OiNbQydYw==",
+      "dev": true
+    },
     "node_modules/@types/stack-utils": {
       "version": "2.0.3",
       "resolved": "https://registry.npmjs.org/@types/stack-utils/-/stack-utils-2.0.3.tgz",
@@ -6266,6 +6274,11 @@
       "integrity": "sha512-nnbWWOkoWyUsTjKrhgD0dcz22mdkSnpYqbEjIm2nhwhuxlSkpywJmBo8h0ZqJdkp73mb90SssHkN4rsRaBAfAA==",
       "dev": true
     },
+    "node_modules/nanoid": {
+      "version": "2.1.11",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-2.1.11.tgz",
+      "integrity": "sha512-s/snB+WGm6uwi0WjsZdaVcuf3KJXlfGl2LcxgwkEwJF0D/BWzVWAZW/XY4bFaiR7s0Jk3FPvlnepg1H1b1UwlA=="
+    },
     "node_modules/natural-compare": {
       "version": "1.4.0",
       "resolved": "https://registry.npmjs.org/natural-compare/-/natural-compare-1.4.0.tgz",
@@ -7425,6 +7438,15 @@
         "url": "https://github.com/sponsors/isaacs"
       }
     },
+    "node_modules/shortid": {
+      "version": "2.2.16",
+      "resolved": "https://registry.npmjs.org/shortid/-/shortid-2.2.16.tgz",
+      "integrity": "sha512-Ugt+GIZqvGXCIItnsL+lvFJOiN7RYqlGy7QE41O3YC1xbNSeDGIRO7xg2JJXIAj1cAGnOeC1r7/T9pgrtQbv4g==",
+      "deprecated": "Package no longer supported. Contact Support at https://www.npmjs.com/support for more info.",
+      "dependencies": {
+        "nanoid": "^2.1.0"
+      }
+    },
     "node_modules/side-channel": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/side-channel/-/side-channel-1.0.4.tgz",

package.json

@@ -24,7 +24,8 @@
     "@nestjs/core": "^10.0.0",
     "@nestjs/platform-express": "^10.0.0",
     "reflect-metadata": "^0.1.13",
-    "rxjs": "^7.8.1"
+    "rxjs": "^7.8.1",
+    "shortid": "^2.2.16"
   },
   "devDependencies": {
     "@nestjs/cli": "^10.0.0",
@@ -33,6 +34,7 @@
     "@types/express": "^4.17.17",
     "@types/jest": "^29.5.2",
     "@types/node": "^20.3.1",
+    "@types/shortid": "^0.0.32",
     "@types/supertest": "^2.0.12",
     "@typescript-eslint/eslint-plugin": "^5.59.11",
     "@typescript-eslint/parser": "^5.59.11",

src/app.controller.ts

@@ -1,12 +1,7 @@
 import { Controller, Get } from '@nestjs/common';
-import { AppService } from './app.service';
 
 @Controller()
 export class AppController {
-  constructor(private readonly appService: AppService) {}
+  constructor() {}
 
-  @Get()
-  getHello(): string {
-    return this.appService.getHello();
-  }
 }

src/app.module.ts

@@ -1,11 +1,9 @@
 import { Module } from '@nestjs/common';
 import { AppController } from './app.controller';
-import { AppService } from './app.service';
 import { UrlShortenerModule } from './url-shortener/url-shortener.module';
 
 @Module({
   imports: [UrlShortenerModule],
   controllers: [AppController],
-  providers: [AppService],
 })
 export class AppModule {}

src/app.service.ts

@@ -1,8 +0,0 @@
-import { Injectable } from '@nestjs/common';
-
-@Injectable()
-export class AppService {
-  getHello(): string {
-    return 'Hello World!';
-  }
-}

src/url-shortener/url-shortener.controller.ts

@@ -1,6 +1,27 @@
-import { Controller } from '@nestjs/common';
+import { Controller, Post, Body, Get, Param, Redirect, HttpException, HttpStatus } from '@nestjs/common';
+import { UrlShortenerService } from './url-shortener.service';
 
 @Controller('url-shortener')
 export class UrlShortenerController {
+  constructor(private readonly urlShortenerService: UrlShortenerService) {}
 
+  @Post('shorten')
+  shortenUrl(@Body('url') url: string): { shortUrl: string } {
+    // example route http://localhost:3000/url-shortener/shorten POST body { url: 'https://www.google.com' }
+    if (!url) {
+      throw new HttpException('URL is required', HttpStatus.BAD_REQUEST);
+    }
+    const shortUrl = this.urlShortenerService.generateShortUrl(url);
+    return { shortUrl };
+  }
+
+  @Get(':shortUrl')
+  @Redirect()
+  async resolveShortUrl(@Param('shortUrl') shortUrl: string) {
+    const originalUrl = this.urlShortenerService.getOriginalUrl(shortUrl);
+    if (!originalUrl) {
+      throw new HttpException('URL not found!', HttpStatus.NOT_FOUND);
+    }
+    return { url: originalUrl };
+  }
 }

src/url-shortener/url-shortener.service.ts

@@ -1,4 +1,20 @@
 import { Injectable } from '@nestjs/common';
+import * as shortid from 'shortid';
 
 @Injectable()
-export class UrlShortenerService {}
+export class UrlShortenerService {
+  private urlMap = new Map<string, string>();
+
+  generateShortUrl(originalUrl: string): string {
+    if(!originalUrl) {
+      throw new Error('URL is required');
+    }
+    let shortUrl = shortid.generate();
+    this.urlMap.set(shortUrl, originalUrl);
+    return shortUrl
+  }
+
+  getOriginalUrl(shortUrl: string): string | undefined {
+    return this.urlMap.get(shortUrl);
+  }
+}