feat(server): introduce user friendly server errors (#7111)

packages/backend/server/src/fundamentals/nestjs/exception.ts

@@ -1,25 +1,87 @@
-import { ArgumentsHost, Catch, HttpException } from '@nestjs/common';
+import { ArgumentsHost, Catch, Logger } from '@nestjs/common';
 import { BaseExceptionFilter } from '@nestjs/core';
 import { GqlContextType } from '@nestjs/graphql';
+import { ThrottlerException } from '@nestjs/throttler';
 import { Response } from 'express';
+import { of } from 'rxjs';
+
+import {
+  InternalServerError,
+  TooManyRequest,
+  UserFriendlyError,
+} from '../error';
+import { metrics } from '../metrics';
+
+export function mapAnyError(error: any): UserFriendlyError {
+  if (error instanceof UserFriendlyError) {
+    return error;
+  } else if (error instanceof ThrottlerException) {
+    return new TooManyRequest();
+  } else {
+    const e = new InternalServerError();
+    e.cause = error;
+    return e;
+  }
+}
 
 @Catch()
 export class GlobalExceptionFilter extends BaseExceptionFilter {
+  logger = new Logger('GlobalExceptionFilter');
   override catch(exception: Error, host: ArgumentsHost) {
+    const error = mapAnyError(exception);
     // with useGlobalFilters, the context is always HTTP
-
     if (host.getType<GqlContextType>() === 'graphql') {
       // let Graphql LoggerPlugin handle it
       // see '../graphql/logger-plugin.ts'
-      throw exception;
+      throw error;
     } else {
-      if (exception instanceof HttpException) {
-        const res = host.switchToHttp().getResponse<Response>();
-        res.status(exception.getStatus()).send(exception.getResponse());
-        return;
-      } else {
-        super.catch(exception, host);
-      }
+      error.log('HTTP');
+      metrics.controllers.counter('error').add(1, { status: error.status });
+      const res = host.switchToHttp().getResponse<Response>();
+      res.status(error.status).send(error.json());
+      return;
     }
   }
 }
+
+export const GatewayErrorWrapper = (event: string): MethodDecorator => {
+  // @ts-expect-error allow
+  return (
+    _target,
+    _key,
+    desc: TypedPropertyDescriptor<(...args: any[]) => any>
+  ) => {
+    const originalMethod = desc.value;
+    if (!originalMethod) {
+      return desc;
+    }
+
+    desc.value = async function (...args: any[]) {
+      try {
+        return await originalMethod.apply(this, args);
+      } catch (error) {
+        const mappedError = mapAnyError(error);
+        mappedError.log('Websocket');
+        metrics.socketio
+          .counter('error')
+          .add(1, { event, status: mappedError.status });
+
+        return {
+          error: mappedError.json(),
+        };
+      }
+    };
+
+    return desc;
+  };
+};
+
+export function mapSseError(originalError: any) {
+  const error = mapAnyError(originalError);
+  error.log('Sse');
+  metrics.sse.counter('error').add(1, { status: error.status });
+  return of({
+    type: 'error' as const,
+    data: error.json(),
+  });
+}