Merge pull request #1 from harrylowkey/feat/grpc-exception-filter

feat: grpc exception filter

libs/constants/grpc_status_code_mapping.constant.ts

@@ -0,0 +1,30 @@
+import { HttpStatus } from '@nestjs/common';
+import { status } from '@grpc/grpc-js';
+
+export const HTTP_STATUS_CODE: Record<number, number> = {
+    // standard gRPC error mapping
+    // https://cloud.google.com/apis/design/errors#handling_errors
+    [HttpStatus.BAD_REQUEST]: status.INVALID_ARGUMENT,
+    [HttpStatus.UNAUTHORIZED]: status.UNAUTHENTICATED,
+    [HttpStatus.FORBIDDEN]: status.PERMISSION_DENIED,
+    [HttpStatus.NOT_FOUND]: status.NOT_FOUND,
+    [HttpStatus.CONFLICT]: status.ALREADY_EXISTS,
+    [HttpStatus.GONE]: status.ABORTED,
+    [HttpStatus.TOO_MANY_REQUESTS]: status.RESOURCE_EXHAUSTED,
+    499: status.CANCELLED,
+    [HttpStatus.INTERNAL_SERVER_ERROR]: status.INTERNAL,
+    [HttpStatus.NOT_IMPLEMENTED]: status.UNIMPLEMENTED,
+    [HttpStatus.BAD_GATEWAY]: status.UNKNOWN,
+    [HttpStatus.SERVICE_UNAVAILABLE]: status.UNAVAILABLE,
+    [HttpStatus.GATEWAY_TIMEOUT]: status.DEADLINE_EXCEEDED,
+
+    // additional built-in http exceptions
+    // https://docs.nestjs.com/exception-filters#built-in-http-exceptions
+    [HttpStatus.HTTP_VERSION_NOT_SUPPORTED]: status.UNAVAILABLE,
+    [HttpStatus.PAYLOAD_TOO_LARGE]: status.OUT_OF_RANGE,
+    [HttpStatus.UNSUPPORTED_MEDIA_TYPE]: status.CANCELLED,
+    [HttpStatus.UNPROCESSABLE_ENTITY]: status.CANCELLED,
+    [HttpStatus.I_AM_A_TEAPOT]: status.UNKNOWN,
+    [HttpStatus.METHOD_NOT_ALLOWED]: status.CANCELLED,
+    [HttpStatus.PRECONDITION_FAILED]: status.FAILED_PRECONDITION
+};

libs/enums/grpc-status.enum.ts

@@ -0,0 +1,19 @@
+export enum GrpcStatusEnum {
+    OK = 0,
+    CANCELLED = 1,
+    UNKNOWN = 2,
+    INVALID_ARGUMENT = 3,
+    DEADLINE_EXCEEDED = 4,
+    NOT_FOUND = 5,
+    ALREADY_EXISTS = 6,
+    PERMISSION_DENIED = 7,
+    RESOURCE_EXHAUSTED = 8,
+    FAILED_PRECONDITION = 9,
+    ABORTED = 10,
+    OUT_OF_RANGE = 11,
+    UNIMPLEMENTED = 12,
+    INTERNAL = 13,
+    UNAVAILABLE = 14,
+    DATA_LOSS = 15,
+    UNAUTHENTICATED = 16
+}

libs/filters/base-exception.filter.ts

@@ -1,15 +1,24 @@
 import { ArgumentsHost } from '@nestjs/common';
 import { throwError } from 'rxjs';
+import { status } from '@grpc/grpc-js';
+import { HTTP_STATUS_CODE } from '../constants/grpc_status_code_mapping.constant';
 
 export abstract class BaseExceptionFilter {
     protected isMicroservice: boolean = false;
+    protected isGrpc: boolean = false;
 
     protected getLanguage(host: ArgumentsHost) {
         return host.switchToHttp().getRequest().i18nLang;
     }
 
     protected responseError(host: ArgumentsHost, code, message, errors = null) {
-        if (this.isMicroservice) {
+        if (this.isGrpc) {
+            return throwError(() => ({
+                message: message,
+                details: errors.message[0],
+                code: HTTP_STATUS_CODE[code] ?? status.UNKNOWN
+            }));
+        } else if (this.isMicroservice) {
             return throwError(() =>
                 JSON.stringify({
                     message: message,

libs/filters/grpc-exception.filter.ts

@@ -0,0 +1,10 @@
+import { Catch } from '@nestjs/common';
+import { HttpExceptionFilter } from './http-exception.filter';
+
+@Catch()
+export class GrpcExceptionFilter extends HttpExceptionFilter {
+    constructor() {
+        super();
+        this.isGrpc = true;
+    }
+}

libs/filters/http-exception.filter.ts

@@ -17,6 +17,7 @@ import { trans } from '@hodfords/nestjs-cls-translation';
 @Catch()
 export class HttpExceptionFilter extends BaseExceptionFilter implements ExceptionFilter {
     protected isMicroservice: boolean = false;
+    protected isGrpc: boolean = false;
 
     catch(exception, host: ArgumentsHost) {
         let language = this.getLanguage(host);
@@ -28,7 +29,7 @@ export class HttpExceptionFilter extends BaseExceptionFilter implements Exceptio
             };
             return this.catchBadRequestWithArgs(host, 'error.field_malformed', language, args);
         } else if (exception instanceof ValidateException) {
-            return new ValidatorExceptionFilter(this.isMicroservice).catch(exception, host);
+            return new ValidatorExceptionFilter(this.isMicroservice, this.isGrpc).catch(exception, host);
         } else if (exception instanceof PayloadTooLargeException) {
             return this.catchPayloadTooLargeException(host, 'error.multer.file_too_large', language);
         } else if (exception.type === 'entity.too.large') {

libs/filters/validator-exception.filter.ts

@@ -7,9 +7,10 @@ import { trans } from '@hodfords/nestjs-cls-translation';
 
 @Catch()
 export class ValidatorExceptionFilter extends BaseExceptionFilter implements ExceptionFilter {
-    constructor(isMicroservice: boolean) {
+    constructor(isMicroservice: boolean, isGrpc: boolean) {
         super();
         this.isMicroservice = isMicroservice;
+        this.isGrpc = isGrpc;
     }
 
     catch(exception: ValidateException, host: ArgumentsHost) {

libs/index.ts

@@ -5,7 +5,9 @@ export * from './filters/base-exception.filter';
 export * from './filters/http-exception.filter';
 export * from './filters/microservice-exception.filter';
 export * from './filters/validator-exception.filter';
+export * from './filters/grpc-exception.filter';
 export * from './interfaces/validation-error.interface';
 export * from './types/validation-error-exception.type';
 export * from './types/validation-error-exception-detail.type';
 export * from './types/validation-error-exception-message.type';
+export * from './enums/grpc-status.enum';