Issue 95 - Feature: Set up environment configuration system

backend/.env

@@ -4,4 +4,8 @@ JWT_SECRET=your_jwt_secret_key_change_in_production
 JWT_EXPIRES_IN=7d
 NODE_ENV=development
 # comma separated list of allowed origins for *production*
-ALLOWED_ORIGINS=https://scheduleapp.com,https://www.scheduleapp.com 
+ALLOWED_ORIGINS=https://scheduleapp.com,https://www.scheduleapp.com
+# Email Configuration
+EMAIL_SERVICE=gmail
+[email protected]
+EMAIL_PASS=your-password

backend/.env.example

@@ -3,6 +3,10 @@ PORT=8123
 MONGODB_URI=mongodb://localhost:27017/scheduleapp
 JWT_SECRET=your_jwt_secret_key_change_in_production
 JWT_EXPIRES_IN=7d
-NODE_ENV=development
+NODE_ENV=development # development, production, test 
 # comma-separated list of allowed origins for cors in production
-ALLOWED_ORIGINS=https://your-app.com,https://www.your-app.com 
+ALLOWED_ORIGINS=https://your-app.com,https://www.your-app.com
+# Email Configuration
+EMAIL_SERVICE=gmail
+[email protected]
+EMAIL_PASS=example_password

backend/src/config/db.ts

@@ -1,18 +1,15 @@
 import mongoose from 'mongoose';
-import dotenv from 'dotenv';
-
-// load environment variables
-dotenv.config();
+import { config } from './env.config';
 
 // connection function
 const connectDB = async (): Promise<void> => {
   try {
-    const conn = await mongoose.connect(process.env.MONGODB_URI as string);
+    const conn = await mongoose.connect(config.mongodb.uri);
     console.log(`mongodb connected: ${conn.connection.host}`);
   } catch (error: any) {
     console.error(`error: ${error.message}`);
     process.exit(1);
   }
 };
 
-export default connectDB; 
+export default connectDB;

backend/src/config/env.config.ts

@@ -0,0 +1,99 @@
+import dotenv from 'dotenv';
+import path from 'path';
+
+// Load .env file from backend/.env
+dotenv.config({ path: path.resolve(__dirname, "../../.env") });
+
+/*
+ * Config interface for env variables
+ */
+interface Config {
+  port: number;
+  nodeEnv: string;
+  mongodb: {
+    uri: string;
+  };
+  jwt: {
+    secret: string;
+    expiresIn: string;
+  };
+  cors: {
+    allowedOrigins: string[];
+  };
+  email: {
+    service: string;
+    user: string;
+    pass: string;
+  };
+}
+
+/**
+ * Validates that all required env variables are present
+ * Throws an error if any are missing
+ */
+function validateConfig(): Config {
+  // List of required environment variables
+  const requiredEnvVars = [
+    "PORT",
+    "MONGODB_URI",
+    "JWT_SECRET",
+    "JWT_EXPIRES_IN",
+    "NODE_ENV",
+    "EMAIL_SERVICE",
+    "EMAIL_USER",
+    "EMAIL_PASS",
+  ];
+
+  // Check for missing required variables
+  const missingVars = requiredEnvVars.filter(
+    (varName) => !process.env[varName]
+  );
+
+  // Throw error if atleast one env variable is missing
+  if (missingVars.length > 0) {
+    throw new Error(
+      `Missing required environment variables: ${missingVars.join(", ")}\n`
+    );
+  }
+
+  // Parse and validate PORT
+  const port = parseInt(process.env.PORT!, 10);
+  if (isNaN(port) || port < 0 || port > 65535) {
+    throw new Error(
+      `Invalid PORT value: ${process.env.PORT}. Must be a number between 0 and 65535.`
+    );
+  }
+
+  // Build the configuration object
+  const config: Config = {
+    port,
+    nodeEnv: process.env.NODE_ENV!.trim(),
+    mongodb: {
+      uri: process.env.MONGODB_URI!.trim(),
+    },
+    jwt: {
+      secret: process.env.JWT_SECRET!.trim(),
+      expiresIn: process.env.JWT_EXPIRES_IN!.trim(),
+    },
+    cors: {
+      allowedOrigins: process.env.ALLOWED_ORIGINS
+        ? process.env.ALLOWED_ORIGINS.split(",").map((origin) => origin.trim())
+        : [],
+    },
+    email: {
+      service: process.env.EMAIL_SERVICE!.trim(),
+      user: process.env.EMAIL_USER!.trim(),
+      pass: process.env.EMAIL_PASS!.trim(),
+    },
+  };
+
+  return config;
+}
+
+// Validate and export configuration
+export const config = validateConfig();
+
+// Export helper functions for environment checks
+export const isDevelopment = (): boolean => config.nodeEnv === "development";
+export const isProduction = (): boolean => config.nodeEnv === "production";
+export const isTest = (): boolean => config.nodeEnv === "test";

backend/src/index.ts

@@ -1,38 +1,36 @@
 import express from 'express';
 import cors from 'cors';
-import dotenv from 'dotenv';
 import connectDB from './config/db';
 import routes from './routes';
 import { notFound, errorHandler } from './middleware/errorMiddleware';
-
-// load environment variables
-dotenv.config();
+import { config, isProduction } from './config/env.config';
 
 // create express app
 const app = express();
-const port = process.env.PORT || 5000;
 
 // connect to mongodb
 connectDB();
 
 // cors configiuration
-const isProduction = process.env.NODE_ENV === 'production';
 const corsOptions = {
   // in development, allow all localhost and 127.0.0.1 requests
   // in production, this would be replaced with specific allowed origins
-  origin: isProduction 
-    ? process.env.ALLOWED_ORIGINS?.split(',') || [] 
-    : (origin: string | undefined, callback: (err: Error | null, allow?: boolean) => void) => {
-      // allow requests with no origin (like mobile apps, curl, postman)
-      if (!origin) return callback(null, true);
-
-      // allow all localhost and 127.0.0.1 requests in development
+  origin: isProduction()
+    ? config.cors.allowedOrigins
+    : (
+        origin: string | undefined,
+        callback: (err: Error | null, allow?: boolean) => void
+      ) => {
+        // allow requests with no origin (like mobile apps, curl, postman)
+        if (!origin) return callback(null, true);
+
+        // allow all localhost and 127.0.0.1 requests in development
       if (origin.includes('localhost') || origin.includes('127.0.0.1')) {
-        return callback(null, true);
-      }
-      
+          return callback(null, true);
+        }
+
       callback(new Error('Not allowed by CORS'));
-    },
+      },
   credentials: true,
   methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
   allowedHeaders: ['Content-Type', 'Authorization']
@@ -62,7 +60,16 @@ app.use(notFound);
 app.use(errorHandler);
 
 // start server
-app.listen(port, () => {
-  console.log(`server running on port ${port} (http://localhost:${port})`);
-  console.log(`CORS enabled for: ${isProduction ? process.env.ALLOWED_ORIGINS || 'specific origins' : 'all localhost origins'}`);
-}); 
+app.listen(config.port, () => {
+  console.log(
+    `server running on port ${config.port} (http://localhost:${config.port})`
+  );
+  console.log(`Environment: ${config.nodeEnv}`);
+  console.log(
+    `CORS enabled for: ${
+      isProduction()
+        ? config.cors.allowedOrigins.join(", ") || "specific origins"
+        : "all localhost origins"
+    }`
+  );
+});

backend/src/middleware/errorMiddleware.ts

@@ -1,4 +1,5 @@
 import { Request, Response, NextFunction } from 'express';
+import { isProduction } from "../config/env.config";
 
 // not found error handler
 export const notFound = (req: Request, res: Response, next: NextFunction) => {
@@ -10,9 +11,9 @@ export const notFound = (req: Request, res: Response, next: NextFunction) => {
 // general error handler
 export const errorHandler = (err: Error, req: Request, res: Response, next: NextFunction) => {
   const statusCode = res.statusCode === 200 ? 500 : res.statusCode;
-  
+
   res.status(statusCode).json({
     message: err.message,
-    stack: process.env.NODE_ENV === 'production' ? null : err.stack,
+    stack: isProduction() ? null : err.stack,
   });
-}; 
+};

backend/src/routes/index.ts

@@ -1,7 +1,7 @@
 import express from 'express';
 import mongoose from 'mongoose';
-import dotenv from 'dotenv';
 import { Router } from 'express';
+import { config } from "../config/env.config";
 
 // importing status routes
 import statusRoutes from './statusRoutes';
@@ -10,7 +10,7 @@ const router = Router();
 
 // api root route - returns general api info
 router.get('/', (req, res) => {
-  res.status(200).json({ 
+  res.status(200).json({
     message: 'api is running',
     version: '1.0.0',
     endpoints: {
@@ -31,7 +31,7 @@ router.get('/health', (req, res) => {
 // mongodb status check
 router.get('/db-status', (req, res) => {
   console.log('mongodb status check endpoint hit');
-  
+
   try {
     const state = mongoose.connection.readyState;
     /*
@@ -40,7 +40,7 @@ router.get('/db-status', (req, res) => {
       2 = connecting
       3 = disconnecting
     */
-    
+
     let status: {
       connected: boolean;
       state: string;
@@ -50,7 +50,7 @@ router.get('/db-status', (req, res) => {
       connected: false,
       state: 'unknown',
     };
-    
+
     switch(state) {
       case 0:
         status.state = 'disconnected';
@@ -72,7 +72,7 @@ router.get('/db-status', (req, res) => {
         status.error = 'Disconnecting from MongoDB';
         break;
     }
-    
+
     res.status(200).json(status);
   } catch (error: any) {
     res.status(500).json({
@@ -84,23 +84,25 @@ router.get('/db-status', (req, res) => {
 
 // env variables check
 router.get('/env-check', (req, res) => {
-  console.log('environment variables check endpoint hit');
-
-  // required env variables
-  const requiredVars = [
-    'PORT',
-    'MONGODB_URI',
-    'JWT_SECRET',
-    'JWT_EXPIRES_IN'
-  ];
-
-  const missingVars = requiredVars.filter(varName => !process.env[varName]);
-
+  // Config is already validated at startup
   res.status(200).json({
-    valid: missingVars.length === 0,
-    missing: missingVars.length > 0 ? missingVars : undefined,
-    total: requiredVars.length,
-    present: requiredVars.length - missingVars.length
+    valid: true,
+    message: "All environment variables are valid",
+    config: {
+      port: config.port,
+      nodeEnv: config.nodeEnv,
+      mongodb: {
+        // finds "//username:password@" and replaces with "//<credentials>@"
+        uri: config.mongodb.uri.replace(/\/\/.*@/, "//<credentials>@"),
+      }, // Hide credentials
+      jwt: { expiresIn: config.jwt.expiresIn },
+      cors: { allowedOrigins: config.cors.allowedOrigins },
+      email: {
+        service: config.email.service,
+        user: config.email.user,
+        pass: "***hidden***",
+      },
+    },
   });
 });
 
@@ -112,4 +114,4 @@ router.get('/test', (req, res) => {
 // mounting status routes
 router.use('/status', statusRoutes);
 
-export default router; 
+export default router;