feat: create centralized path utilities for improved path resolution and environment awareness

ReleaseNotes.json

@@ -29,6 +29,9 @@
             "Removed all `.js` extensions from backend imports (handlers, middleware, routes, services)",
             "Added `tsup.config.ts` with optimized ESM output configuration",
             "Updated build script from `tsc` to `tsup` in package.json",
+            "Created centralized path utilities in `src/backend/utils/paths.ts`",
+            "Replaced duplicated `__dirname` logic with `resolveFromRoot()` function",
+            "Path resolution now environment-aware (dev vs production)",
             "Maintained development mode with nodemon for hot-reload support"
           ]
         },

src/backend/index.ts

@@ -3,8 +3,6 @@ import cors from 'cors';
 import helmet from 'helmet';
 import compression from 'compression';
 import path from 'path';
-import { fileURLToPath } from 'url';
-import { dirname } from 'path';
 import { setTimeout } from 'timers';
 import apiRoutes from './routes/api';
 import apiKeyAuth from './middleware/auth';
@@ -13,9 +11,7 @@ import config from './services/config';
 import logger from './services/logger';
 import { generateRuntimeConfig } from './services/runtimeConfig';
 import { healthCheckHandler } from './handlers/healthHandler';
-
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
+import { paths } from './utils/paths';
 
 const app = express();
 
@@ -72,7 +68,7 @@ const basePath = config.basePath.endsWith('/')
   : config.basePath;
 
 // Serve static frontend files
-const frontendPath = path.join(__dirname, '../frontend');
+const frontendPath = paths.frontendDir;
 
 // Generate runtime configuration (env.js) at startup
 generateRuntimeConfig(frontendPath, basePath);

src/backend/routes/api.ts

@@ -1,8 +1,7 @@
 import { Router, Request, Response } from 'express';
 import Joi from 'joi';
 import { readFileSync } from 'fs';
-import { fileURLToPath } from 'url';
-import { dirname, join } from 'path';
+import paths from '../utils/paths';
 import geoIPService from '../services/geoip';
 import logger from '../services/logger';
 import config from '../services/config';
@@ -13,9 +12,6 @@ import {
   ErrorResponse,
 } from '../types/index';
 
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
-
 const router = Router();
 
 // Validation schemas
@@ -276,10 +272,8 @@ router.get('/version', (_req: Request, res: Response): void => {
 // Get release notes
 router.get('/release-notes', (_req: Request, res: Response): void => {
   try {
-    const releaseNotesPath = join(__dirname, '../../../ReleaseNotes.json');
-    const releaseNotesContent = readFileSync(releaseNotesPath, 'utf-8');
+    const releaseNotesContent = readFileSync(paths.releaseNotesFile, 'utf-8');
     const releaseNotes = JSON.parse(releaseNotesContent);
-
     logger.debug('Release notes retrieved successfully');
     res.json(releaseNotes);
   } catch (error) {
@@ -294,10 +288,8 @@ router.get('/release-notes', (_req: Request, res: Response): void => {
 // Get overview
 router.get('/overview', (_req: Request, res: Response): void => {
   try {
-    const overviewPath = join(__dirname, '../../../Overview.json');
-    const overviewContent = readFileSync(overviewPath, 'utf-8');
+    const overviewContent = readFileSync(paths.overviewFile, 'utf-8');
     const overview = JSON.parse(overviewContent);
-
     logger.debug('Overview retrieved successfully');
     res.json(overview);
   } catch (error) {

src/backend/services/config.ts

@@ -1,14 +1,8 @@
 import { Config, LogLevel, LOG_LEVELS } from '../types/index';
-import path from 'path';
 import { config as dotenvConfig } from 'dotenv';
-import { fileURLToPath } from 'url';
-import { dirname } from 'path';
+import { paths } from '../utils/paths';
 
-const __filename = fileURLToPath(import.meta.url);
-const __dirname = dirname(__filename);
-
-// Load .env file from root directory
-dotenvConfig({ path: path.join(__dirname, '../../../.env') });
+dotenvConfig({ path: paths.envFile });
 
 // Parse log level from environment variable
 const parseLogLevel = (level?: string): LogLevel => {

src/backend/utils/paths.ts

@@ -0,0 +1,48 @@
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+const isProduction = process.env.NODE_ENV === 'production';
+
+const findProjectRoot = (): string => {
+  // In production (Docker), process.cwd() is /app (project root)
+  if (isProduction) {
+    return process.cwd();
+  }
+
+  if (import.meta.url) {
+    const __filename = fileURLToPath(import.meta.url);
+    const __dirname = path.dirname(__filename);
+    const rootPath = path.resolve(__dirname, '../../..');
+    return rootPath;
+  }
+
+  throw new Error(
+    'import.meta.url is required in development to resolve project root'
+  );
+};
+
+const projectRootPath = findProjectRoot();
+console.log('[paths] Project root resolved:', projectRootPath);
+
+const resolveFilePath = (...relativePath: string[]): string => {
+  return path.join(projectRootPath, ...relativePath);
+};
+
+const envPath = resolveFilePath('.env');
+const releaseNotesPath = resolveFilePath('ReleaseNotes.json');
+const overviewPath = resolveFilePath('Overview.json');
+const frontendPrefix = isProduction ? 'dist' : 'src';
+const frontendPath = resolveFilePath(frontendPrefix, 'frontend');
+
+const paths = {
+  projectRoot: projectRootPath,
+  envFile: envPath,
+  releaseNotesFile: releaseNotesPath,
+  overviewFile: overviewPath,
+  frontendDir: frontendPath,
+};
+
+console.log('[paths] App paths resolved:', paths);
+
+export { paths };
+export default paths;