fix: UniqueConflict handling

src/util/unique-conflict.decorator.ts

@@ -1,31 +1,38 @@
-import {applyDecorators, ArgumentsHost, Catch, ConflictException, UseFilters} from '@nestjs/common';
+import {applyDecorators, ArgumentsHost, Catch, ExceptionFilter, HttpStatus, UseFilters} from '@nestjs/common';
 import {ApiConflictResponse} from '@nestjs/swagger';
 import {mongo} from 'mongoose';
-import {BaseExceptionFilter} from '@nestjs/core';
 
 // TODO move everything to @mean-stream/nestx
 
 /**
  * Converts a MongoServerError with code 11000 into a ConflictException with a configurable message.
  */
 @Catch(mongo.MongoServerError)
-class ConflictExceptionFilter extends BaseExceptionFilter {
+class ConflictExceptionFilter implements ExceptionFilter {
   constructor(
     private description: Partial<Record<string, string>>,
   ) {
-    super();
   }
 
   catch(exception: mongo.MongoServerError, host: ArgumentsHost): any {
+    const ctx = host.switchToHttp();
+    const response = ctx.getResponse();
     if (exception.code !== 11000) {
-      return super.catch(exception, host);
+      response.status(500).json({
+        statusCode: 500,
+        message: exception.message,
+      });
+      return;
     }
 
     const keyPattern = exception.keyPattern; // e.g. { username: 1 }
     const values = exception.keyValue; // e.g. { username: 'test' }
     const indexKey = Object.keys(keyPattern).join('_');
-    const http = new ConflictException(this.description[indexKey] ?? `Unique constraint violation on '${indexKey}' with value ${JSON.stringify(values)}.`);
-    return super.catch(http, host);
+    const message = this.description[indexKey] ?? `Unique constraint violation on '${indexKey}' with value ${JSON.stringify(values)}.`;
+    response.status(HttpStatus.CONFLICT).json({
+      statusCode: HttpStatus.CONFLICT,
+      message,
+    });
   }
 }