refactor(core,express,fastify): HTTP adapter error mapping

Author: maxbronnikov10

packages/core/adapters/http-adapter.ts

@@ -143,6 +143,10 @@ export abstract class AbstractHttpAdapter<
     return path;
   }
 
+  public mapException(error: unknown): unknown {
+    return error;
+  }
+
   abstract close();
   abstract initHttpServer(options: NestApplicationOptions);
   abstract useStaticAssets(...args: any[]);

packages/core/router/routes-resolver.ts

@@ -162,7 +162,7 @@ export class RoutesResolver implements Resolver {
       res: TResponse,
       next: Function,
     ) => {
-      throw this.mapExternalException(err);
+      throw this.container.getHttpAdapterRef().mapException(err);
     };
     const handler = this.routerExceptionsFilter.create(
       {},
@@ -178,18 +178,6 @@ export class RoutesResolver implements Resolver {
       );
   }
 
-  public mapExternalException(err: any) {
-    switch (true) {
-      // SyntaxError is thrown by Express body-parser when given invalid JSON (#422, #430)
-      // URIError is thrown by Express when given a path parameter with an invalid percentage
-      // encoding, e.g. '%FF' (#8915)
-      case err instanceof SyntaxError || err instanceof URIError:
-        return new BadRequestException(err.message);
-      default:
-        return err;
-    }
-  }
-
   private getModulePathMetadata(metatype: Type<unknown>): string | undefined {
     const modulesContainer = this.container.getModules();
     const modulePath = Reflect.getMetadata(

packages/core/test/router/routes-resolver.spec.ts

@@ -1,9 +1,4 @@
-import {
-  BadRequestException,
-  Module,
-  Post,
-  VersioningType,
-} from '@nestjs/common';
+import { Module, Post, VersioningType } from '@nestjs/common';
 import { MODULE_PATH } from '@nestjs/common/constants';
 import { expect } from 'chai';
 import * as sinon from 'sinon';
@@ -318,32 +313,6 @@ describe('RoutesResolver', () => {
     });
   });
 
-  describe('mapExternalExceptions', () => {
-    describe('when exception prototype is', () => {
-      describe('SyntaxError', () => {
-        it('should map to BadRequestException', () => {
-          const err = new SyntaxError();
-          const outputErr = routesResolver.mapExternalException(err);
-          expect(outputErr).to.be.instanceof(BadRequestException);
-        });
-      });
-      describe('URIError', () => {
-        it('should map to BadRequestException', () => {
-          const err = new URIError();
-          const outputErr = routesResolver.mapExternalException(err);
-          expect(outputErr).to.be.instanceof(BadRequestException);
-        });
-      });
-      describe('other', () => {
-        it('should behave as an identity', () => {
-          const err = new Error();
-          const outputErr = routesResolver.mapExternalException(err);
-          expect(outputErr).to.be.eql(err);
-        });
-      });
-    });
-  });
-
   describe('registerNotFoundHandler', () => {
     it('should register not found handler', () => {
       routesResolver.registerNotFoundHandler();

packages/platform-express/adapters/express-adapter.ts

@@ -1,4 +1,5 @@
 import {
+  BadRequestException,
   HttpStatus,
   InternalServerErrorException,
   Logger,
@@ -448,6 +449,18 @@ export class ExpressAdapter extends AbstractHttpAdapter<
     throw new Error('Unsupported versioning options');
   }
 
+  public mapException(error: unknown): unknown {
+    switch (true) {
+      // SyntaxError is thrown by Express body-parser when given invalid JSON (#422, #430)
+      // URIError is thrown by Express when given a path parameter with an invalid percentage
+      // encoding, e.g. '%FF' (#8915)
+      case error instanceof SyntaxError || error instanceof URIError:
+        return new BadRequestException(error.message);
+      default:
+        return error;
+    }
+  }
+
   private trackOpenConnections() {
     this.httpServer.on('connection', (socket: Duplex) => {
       this.openConnections.add(socket);

packages/platform-express/test/adapters/express-adapter.spec.ts

@@ -1,9 +1,16 @@
+import { BadRequestException } from '@nestjs/common';
 import { ExpressAdapter } from '@nestjs/platform-express';
 import { expect } from 'chai';
 import * as express from 'express';
 import * as sinon from 'sinon';
 
 describe('ExpressAdapter', () => {
+  let expressAdapter: ExpressAdapter;
+
+  beforeEach(() => {
+    expressAdapter = new ExpressAdapter();
+  });
+
   afterEach(() => sinon.restore());
 
   describe('registerParserMiddleware', () => {
@@ -43,4 +50,24 @@ describe('ExpressAdapter', () => {
       expect(useSpy.called).to.be.false;
     });
   });
+
+  describe('mapException', () => {
+    it('should map URIError with status code to BadRequestException', () => {
+      const error = new URIError();
+      const result = expressAdapter.mapException(error) as BadRequestException;
+      expect(result).to.be.instanceOf(BadRequestException);
+    });
+
+    it('should map SyntaxError with status code to BadRequestException', () => {
+      const error = new SyntaxError();
+      const result = expressAdapter.mapException(error) as BadRequestException;
+      expect(result).to.be.instanceOf(BadRequestException);
+    });
+
+    it('should return error if it is not handler Error', () => {
+      const error = new Error('Test error');
+      const result = expressAdapter.mapException(error);
+      expect(result).to.equal(error);
+    });
+  });
 });

packages/platform-fastify/adapters/fastify-adapter.ts

@@ -1,6 +1,8 @@
 /* eslint-disable @typescript-eslint/no-floating-promises */
 import { FastifyCorsOptions } from '@fastify/cors';
 import {
+  BadRequestException,
+  HttpException,
   HttpStatus,
   Logger,
   RawBodyRequest,
@@ -18,6 +20,7 @@ import { LegacyRouteConverter } from '@nestjs/core/router/legacy-route-converter
 import {
   FastifyBaseLogger,
   FastifyBodyParser,
+  FastifyError,
   FastifyInstance,
   FastifyListenOptions,
   FastifyPluginAsync,
@@ -670,6 +673,25 @@ export class FastifyAdapter<
     return 'fastify';
   }
 
+  public mapException(error: unknown): unknown {
+    if (this.isHttpFastifyError(error)) {
+      return new HttpException(error.message, error.statusCode);
+    }
+
+    return error;
+  }
+
+  private isHttpFastifyError(
+    error: unknown,
+  ): error is FastifyError & { statusCode: number } {
+    // condition based on this code - https://github.com/fastify/fastify-error/blob/d669b150a82968322f9f7be992b2f6b463272de3/index.js#L22
+    return (
+      error instanceof Error &&
+      error.name === 'FastifyError' &&
+      (error as FastifyError).statusCode !== undefined
+    );
+  }
+
   protected registerWithPrefix(
     factory:
       | FastifyPluginCallback<any>

packages/platform-fastify/test/adapters/fastify-adapter.spec.ts

@@ -0,0 +1,48 @@
+import { FastifyAdapter } from '../../adapters/fastify-adapter';
+import { expect } from 'chai';
+import { createError } from '@fastify/error';
+import { HttpException } from '@nestjs/common';
+
+describe('FastifyAdapter', () => {
+  let fastifyAdapter: FastifyAdapter;
+
+  beforeEach(() => {
+    fastifyAdapter = new FastifyAdapter();
+  });
+
+  describe('mapException', () => {
+    it('should map FastifyError with status code to HttpException', () => {
+      const FastifyErrorCls = createError(
+        'FST_ERR_CTP_INVALID_MEDIA_TYPE',
+        'Unsupported Media Type: %s',
+        415,
+      );
+      const error = new FastifyErrorCls();
+
+      const result = fastifyAdapter.mapException(error) as HttpException;
+
+      expect(result).to.be.instanceOf(HttpException);
+      expect(result.message).to.equal(error.message);
+      expect(result.getStatus()).to.equal(415);
+    });
+
+    it('should return FastifyError without user status code to Internal Server Error HttpException', () => {
+      const FastifyErrorCls = createError(
+        'FST_WITHOUT_STATUS_CODE',
+        'Error without status code',
+      );
+      const error = new FastifyErrorCls();
+
+      const result = fastifyAdapter.mapException(error) as HttpException;
+      expect(result).to.be.instanceOf(HttpException);
+      expect(result.message).to.equal(error.message);
+      expect(result.getStatus()).to.equal(500);
+    });
+
+    it('should return error if it is not FastifyError', () => {
+      const error = new Error('Test error');
+      const result = fastifyAdapter.mapException(error);
+      expect(result).to.equal(error);
+    });
+  });
+});