Add exception filters for error handling

Author: RICHARD-Quentin

src/_common/filters/all-exception.filter.ts

@@ -0,0 +1,17 @@
+import { ArgumentsHost, Catch, ExceptionFilter, Logger } from '@nestjs/common';
+import { Response } from 'express';
+@Catch()
+export class AllExceptionFilter implements ExceptionFilter {
+  catch(exception: unknown, host: ArgumentsHost) {
+    Logger.debug(exception['message'], 'MongooseValidationFilter');
+
+    const ctx = host.switchToHttp();
+    const response = ctx.getResponse<Response>();
+    const status = 500;
+
+    return response.status(status).json({
+      statusCode: status,
+      message: exception['message'] || exception['name'] || 'Internal server error',
+    });
+  }
+}

src/_common/filters/identities-validation.filter.ts

@@ -0,0 +1,20 @@
+import { ArgumentsHost, Catch, ExceptionFilter, Logger } from '@nestjs/common';
+import { ValidationException } from '~/_common/errors/ValidationException';
+import { Response } from 'express';
+
+@Catch(ValidationException)
+export class IdentitiesValidationFilter implements ExceptionFilter {
+  catch(exception: ValidationException, host: ArgumentsHost) {
+    const ctx = host.switchToHttp();
+    const response = ctx.getResponse<Response>();
+    const status = exception.getStatus();
+
+    Logger.debug(exception['message'], 'IdentitiesValidationFilter');
+
+    return response.status(status).json({
+      statusCode: status,
+      message: exception.message,
+      validations: exception.getValidations(),
+    });
+  }
+}

src/_common/filters/mongoose-validation.filter.ts

@@ -1,24 +1,15 @@
-import {
-  ArgumentsHost,
-  Catch,
-  ExceptionFilter,
-  HttpException,
-  HttpStatus,
-  Logger,
-} from '@nestjs/common';
+import { ArgumentsHost, Catch, ExceptionFilter, HttpException, HttpStatus, Logger } from '@nestjs/common';
 import { Request, Response } from 'express';
 import { Error } from 'mongoose';
 import { ValidationError } from 'class-validator';
 
 @Catch(Error.ValidationError, Error.CastError, ValidationError)
 export class MongooseValidationFilter implements ExceptionFilter {
-  public catch(
-    exception: Error.ValidationError | Error.CastError | ValidationError,
-    host: ArgumentsHost,
-  ) {
+  public catch(exception: Error.ValidationError | Error.CastError | ValidationError, host: ArgumentsHost) {
     const ctx = host.switchToHttp();
     const request = ctx.getRequest<Request>();
     const response = ctx.getResponse<Response>();
+
     Logger.debug(exception['message'], 'MongooseValidationFilter');
     const debug = {};
     if (process.env.NODE_ENV !== 'production' && request.query['debug']) {
@@ -47,8 +38,7 @@ export class MongooseValidationFilter implements ExceptionFilter {
         if (err.errors[key]['constraints']) {
           Object.keys(err.errors[key]['constraints']).forEach((ckey) => {
             const property = err.errors[key]['property'];
-            validations[`${key}.${property}`] =
-              err.errors[key]['constraints'][ckey];
+            validations[`${key}.${property}`] = err.errors[key]['constraints'][ckey];
           });
           continue;
         }

src/main.ts

@@ -1,13 +1,15 @@
 import { NestFactory } from '@nestjs/core';
 import { AppModule } from './app.module';
 import configInstance from './config';
-import { LogLevel, Logger } from '@nestjs/common';
+import { All, LogLevel, Logger } from '@nestjs/common';
 import { NestExpressApplication } from '@nestjs/platform-express';
 import { utilities as nestWinstonModuleUtilities, WinstonModule } from 'nest-winston';
 import { createLogger } from 'winston';
 import * as winston from 'winston';
 import 'winston-mongodb';
-import { appendFile } from 'fs';
+import { AllExceptionFilter } from './_common/filters/all-exception.filter';
+import { IdentitiesValidationFilter } from './_common/filters/identities-validation.filter';
+import { MongooseValidationFilter } from './_common/filters/mongoose-validation.filter';
 
 declare const module: any;
 (async (): Promise<void> => {
@@ -61,9 +63,12 @@ declare const module: any;
     (await import('./swagger')).default(app);
   }
 
+  app.useGlobalFilters(new AllExceptionFilter(), new MongooseValidationFilter(), new IdentitiesValidationFilter());
+
   await app.listen(3000, async (): Promise<void> => {
     Logger.log(`Application is running on port: ${process.env.PORT || 3000}`);
   });
+
   if (module.hot) {
     module.hot.accept();
     module.hot.dispose((): Promise<void> => app.close());