Merge pull request #2 from weather-blade/errors-middleware

create middleware for handling errors
weather-blade · Mar 9, 2024 · 767acf6 · 767acf6
2 parents e19b6c8 + 080c04e
commit 767acf6
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Showing 4 changed files with 93 additions and 30 deletions.
diff --git a/src/controllers/readings.controller.ts b/src/controllers/readings.controller.ts
@@ -5,6 +5,7 @@ import { ReadingsValidation } from '../validations/readings.validation.js';
 import { redisClient } from '../db/redis.js';
 import { UtilFns } from '../utils/functions.js';
 import { lttb } from '../utils/lttb.js';
+import { AppError } from '../exceptions/AppError.js';
 import type { Request, Response, NextFunction } from 'express';
 
 const WEEK_SECONDS = 604800;
@@ -26,13 +27,12 @@ export class ReadingsController {
 				});
 
 				if (reading === null) {
-					return res.status(404).send('404 Reading not Found');
+					throw new AppError(404, 'Reading not found');
 				}
 
 				res.json(reading);
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -44,7 +44,7 @@ export class ReadingsController {
 				const endTime = new Date(String(req.query.end));
 
 				if (isNaN(startTime.getTime()) || isNaN(endTime.getTime())) {
-					return res.status(400).send('400 Bad Request (use ISO 8601 time format)');
+					throw new AppError(400, 'Bad request (use ISO 8601 time format)');
 				}
 
 				const readings = await prisma.readings.findMany({
@@ -59,8 +59,7 @@ export class ReadingsController {
 
 				res.json(readings);
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -72,8 +71,7 @@ export class ReadingsController {
 			try {
 				const errors = validationResult(req);
 				if (!errors.isEmpty()) {
-					console.error(errors);
-					return res.status(400).json(errors);
+					throw new AppError(400, 'Bad request (wrong year / month format)', errors);
 				}
 
 				const year = parseInt(req.query.year as string);
@@ -82,7 +80,7 @@ export class ReadingsController {
 				const { firstDay, lastDay } = UtilFns.getFirstLastDay(year, month);
 
 				if (isNaN(firstDay.getTime()) || isNaN(lastDay.getTime())) {
-					return res.status(400).send('400 Bad Request (wrong year / month format)');
+					throw new AppError(400, 'Bad request (wrong year / month format)');
 				}
 
 				const cacheName = `month-full-${firstDay.getUTCFullYear()}-${firstDay.getUTCMonth()}`;
@@ -115,8 +113,7 @@ export class ReadingsController {
 					EX: WEEK_SECONDS, // expire after 7 days
 				});
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -128,8 +125,7 @@ export class ReadingsController {
 			try {
 				const errors = validationResult(req);
 				if (!errors.isEmpty()) {
-					console.error(errors);
-					return res.status(400).json(errors);
+					throw new AppError(400, 'Bad request (wrong year / month format)', errors);
 				}
 
 				const year = parseInt(req.query.year as string);
@@ -138,7 +134,7 @@ export class ReadingsController {
 				const { firstDay, lastDay } = UtilFns.getFirstLastDay(year, month);
 
 				if (isNaN(firstDay.getTime()) || isNaN(lastDay.getTime())) {
-					return res.status(400).send('400 Bad Request (wrong year / month format)');
+					throw new AppError(400, 'Bad request (wrong year / month format)');
 				}
 
 				const cacheName = `month-decimated-${firstDay.getUTCFullYear()}-${firstDay.getUTCMonth()}`;
@@ -210,8 +206,7 @@ export class ReadingsController {
 					EX: WEEK_SECONDS, // expire after 7 days
 				});
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -246,8 +241,7 @@ export class ReadingsController {
 					});
 				}
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -263,8 +257,7 @@ export class ReadingsController {
 				const errors = validationResult(req);
 
 				if (!errors.isEmpty()) {
-					console.log(errors);
-					return res.status(400).json(errors);
+					throw new AppError(400, 'Bad request', errors);
 				}
 
 				const temperature_BMP = parseFloat(req.body.temperature_BMP);
@@ -306,8 +299,7 @@ export class ReadingsController {
 				redisClient.del(cacheNameFull);
 				redisClient.del(cacheNameDecimated);
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -324,8 +316,7 @@ export class ReadingsController {
 				const errors = validationResult(req);
 
 				if (!errors.isEmpty()) {
-					console.log(errors);
-					return res.status(400).json(errors);
+					throw new AppError(400, 'Bad request', errors);
 				}
 
 				const id = parseInt(req.params.id);
@@ -359,8 +350,7 @@ export class ReadingsController {
 
 				res.json(result);
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];
@@ -369,15 +359,29 @@ export class ReadingsController {
 
 	public static deleteReading = [
 		checkSchema(ReadingsValidation.readingId),
+
+		async (req: Request, res: Response, next: NextFunction) => {
+			try {
+				const errors = validationResult(req);
+
+				if (!errors.isEmpty()) {
+					throw new AppError(400, 'Bad request', errors);
+				}
+
+				next();
+			} catch (error) {
+				next(error);
+			}
+		},
+
 		checkSchema(ReadingsValidation.readingIdExists),
 
 		async (req: Request, res: Response, next: NextFunction) => {
 			try {
 				const errors = validationResult(req);
 
 				if (!errors.isEmpty()) {
-					console.log(errors);
-					return res.status(400).json(errors);
+					throw new AppError(404, 'Reading not found', errors);
 				}
 
 				const id = parseInt(req.params.id);
@@ -388,8 +392,7 @@ export class ReadingsController {
 
 				res.json(results);
 			} catch (error) {
-				console.error(error);
-				return res.status(500).send('500 Internal Server Error');
+				next(error);
 			}
 		},
 	];

diff --git a/src/exceptions/AppError.ts b/src/exceptions/AppError.ts
@@ -0,0 +1,10 @@
+export class AppError extends Error {
+	public statusCode: number;
+	public errors?: object;
+
+	constructor(statusCode: number, message: string, errors: object | undefined = undefined) {
+		super(message);
+		this.statusCode = statusCode;
+		this.errors = errors;
+	}
+}
diff --git a/src/exceptions/ErrorHandler.ts b/src/exceptions/ErrorHandler.ts
@@ -0,0 +1,47 @@
+import type { Response, Request, NextFunction } from 'express';
+import { AppError } from './AppError.js';
+
+type ErrorResponse = {
+	statusCode: number;
+	message: string;
+	errors?: object;
+};
+
+export class ErrorHandler {
+	public static handleError(
+		err: AppError | Error,
+		req: Request,
+		res: Response,
+		next: NextFunction
+	) {
+		console.log('Error', err);
+
+		if (err instanceof AppError) {
+			ErrorHandler.handleKnownError(err, req, res);
+		} else {
+			ErrorHandler.handleUnknownError(err, req, res);
+		}
+	}
+
+	private static handleKnownError(err: AppError, req: Request, res: Response) {
+		const { statusCode, message } = err;
+
+		const response: ErrorResponse = {
+			statusCode,
+			message,
+		};
+
+		if (err.errors) {
+			response.errors = err.errors;
+		}
+
+		return res.status(statusCode).json(response);
+	}
+
+	private static handleUnknownError(err: Error, req: Request, res: Response) {
+		res.status(500).json({
+			statusCode: 500,
+			message: 'Internal server error',
+		});
+	}
+}
diff --git a/src/index.ts b/src/index.ts
@@ -6,6 +6,7 @@ import compression from 'compression';
 import apiRouter from './routes/api.route.js';
 import { cors } from './middleware/cors.js';
 import { notFound } from './middleware/notFound.js';
+import { ErrorHandler } from './exceptions/ErrorHandler.js';
 
 dotenv.config();
 
@@ -22,6 +23,8 @@ app.use(cors);
 
 app.use('/api', apiRouter);
 
+app.use(ErrorHandler.handleError);
+
 app.use(notFound);
 
 const port = process.env.PORT || 8080;