Use an in-memory repository to save shortened url (#5)

Author: selimyanat

.github/workflows/ci.yml

@@ -37,9 +37,7 @@ jobs:
 
       - name: Create .env file
         run: |
-          echo "MACHINE_ID=1" > .env
-          echo "PORT=3000" >> .env
-          echo "SHORTENED_BASE_URL=http://localhost:3000" >> .env
+          cp .env-dev .env
         working-directory: api  # Ensure it is created inside `api/`
 
       - name: Run Tests (API)

api/.env-dev

@@ -0,0 +1,5 @@
+CACHE_PERSISTENCE= memory
+MACHINE_ID=1
+PORT = 3000
+# Perhpas we should only use a domain name here instead of a full URL (with the port as it is error prone)
+SHORTENED_BASE_URL = http://localhost:3000

api/eslint.config.mjs

@@ -0,0 +1,34 @@
+import js from '@eslint/js';
+import tseslint from '@typescript-eslint/eslint-plugin';
+import tsParser from '@typescript-eslint/parser';
+import prettier from 'eslint-plugin-prettier'; // ✅ Explicitly import the plugin
+import prettierConfig from 'eslint-config-prettier';
+
+export default [
+  js.configs.recommended,
+  {
+    files: ['src/**/*.ts', 'test/**/*.ts'],
+    languageOptions: {
+      parser: tsParser,
+      parserOptions: {
+        project: './tsconfig.json',
+        tsconfigRootDir: import.meta.dirname,
+        sourceType: 'module',
+      },
+    },
+    plugins: {
+      '@typescript-eslint': tseslint,
+      prettier, // ✅ Register Prettier plugin
+    },
+    rules: {
+      ...tseslint.configs.recommended.rules,
+      ...prettierConfig.rules, // ✅ Apply Prettier rules
+      'prettier/prettier': 'error', // ✅ Ensure Prettier rules are enforced
+      '@typescript-eslint/interface-name-prefix': 'off',
+      '@typescript-eslint/explicit-function-return-type': 'off',
+      '@typescript-eslint/explicit-module-boundary-types': 'off',
+      '@typescript-eslint/no-explicit-any': 'off',
+    },
+    ignores: ['**/*.config.js', '**/node_modules/**'],
+  },
+];

api/src/infrastructure/infrastructure.module.ts

@@ -1,10 +1,17 @@
-import { Module } from '@nestjs/common';
-import { ConfigModule } from '@nestjs/config';
-import { InMemoryUrlRepository } from '../infrastructure/repository/in-memory-url.repository';
+import { Module, DynamicModule } from '@nestjs/common';
+import { ConfigModule, ConfigService } from '@nestjs/config';
+import { ShortenUrlRepository } from '../shorten-url/shorten-url.repository';
+import { RepositoryProvider } from './repository/repository.provider';
 
 @Module({
-  imports: [ConfigModule.forRoot()], // Load environment variables
-  controllers: [],
-  providers: [InMemoryUrlRepository],
+  imports: [ConfigModule], // ✅ Ensure ConfigModule is loaded
 })
-export class InfrastructureModule {}
+export class InfrastructureModule {
+  static register(): DynamicModule {
+    return {
+      module: InfrastructureModule,
+      providers: [RepositoryProvider],
+      exports: [ShortenUrlRepository], // ✅ Export repository so other modules can use it
+    };
+  }
+}

api/src/infrastructure/repository/redis-url.repository.ts

@@ -0,0 +1,17 @@
+import { ShortenUrlRepository } from '../../shorten-url/shorten-url.repository';
+import { Injectable } from '@nestjs/common';
+
+@Injectable()
+export class RedisUrlRepository implements ShortenUrlRepository {
+  private urls: Map<string, string> = new Map();
+
+  create(url: string, shortenedUrl: string): Promise<void> {
+    this.urls.set(url, shortenedUrl);
+    return Promise.resolve(undefined);
+  }
+
+  findURL(url: string): Promise<string | null> {
+    const shortenedUrl = this.urls.get(url);
+    return Promise.resolve(shortenedUrl);
+  }
+}

api/src/infrastructure/repository/repository.provider.ts

@@ -0,0 +1,26 @@
+import { ConfigService } from '@nestjs/config';
+import { Provider } from '@nestjs/common';
+import { InMemoryUrlRepository } from './in-memory-url.repository';
+import { ShortenUrlRepository } from '../../shorten-url/shorten-url.repository';
+
+/**
+ * Factory provider to select the appropriate repository implementation based on configuration.
+ */
+export const RepositoryProvider: Provider = {
+  // TODO: Use a constant for the key
+  //provide: 'ShortenUrlRepository',
+  provide: ShortenUrlRepository,
+  useFactory: (configService: ConfigService) => {
+    const persistenceType = configService.get<string>(
+      'CACHE_PERSISTENCE',
+      'memory',
+    );
+
+    if (persistenceType === 'redis') {
+      throw new Error('Redis persistence is not yet implemented');
+    }
+
+    return new InMemoryUrlRepository();
+  },
+  inject: [ConfigService], // ✅ Ensure ConfigService is available
+};

api/src/shorten-url/shorten-url.module.ts

@@ -3,14 +3,20 @@ import { ConfigModule } from '@nestjs/config';
 import { ShortenUrlController } from './shorten-url.controller';
 import { ShortenUrlUsecase } from './shorten-url.usecase';
 import { ShortenUrlIdGeneratorService } from './shorten-url.id-generator.service';
-import { InMemoryUrlRepository } from '../infrastructure/repository/in-memory-url.repository';
 import { InfrastructureModule } from '../infrastructure/infrastructure.module';
+import { ShortenUrlRepository } from './shorten-url.repository';
 
 @Module({
-  imports: [ConfigModule.forRoot(), InfrastructureModule], // Load environment variables
+  imports: [
+    ConfigModule, // ✅ Ensure ConfigModule is available
+    InfrastructureModule.register(), // ✅ Register InfrastructureModule dynamically
+  ],
   controllers: [ShortenUrlController],
   providers: [
-    { provide: 'ShortenUrlRepository', useClass: InMemoryUrlRepository },
+    {
+      provide: 'ShortenUrlRepository',
+      useExisting: ShortenUrlRepository, // ✅ Use injected provider
+    },
     ShortenUrlIdGeneratorService,
     ShortenUrlUsecase,
   ],

api/src/shorten-url/shorten-url.repository.ts

@@ -1,5 +1,5 @@
-export interface ShortenUrlRepository {
-  findURL(url: string): Promise<string | null>;
+export abstract class ShortenUrlRepository {
+  abstract findURL(url: string): Promise<string | null>;
 
-  create(url: string, shortenedUrl: string): Promise<void>;
+  abstract create(url: string, shortenedUrl: string): Promise<void>;
 }