git.squeep.com Git - squeep-api-dingus/blob - lib/dingus.js

   1 /* eslint-disable security/detect-object-injection */
   2 'use strict';
   3
   4 /**
   5  * A very minimal API server framework.
   6  * Just a self-contained router and some request glue.
   7  */
   8
   9 require('./patches');
  10 const { promises: fsPromises } = require('fs');
  11 const path = require('path');
  12 const querystring = require('querystring');
  13 const common = require('./common');
  14 const ContentNegotiation = require('./content-negotiation');
  15 const Enum = require('./enum');
  16 const { DingusError, ResponseError } = require('./errors');
  17 const { extensionToMime } = require('./mime-helper');
  18 const Router = require('./router');
  19 const Template = require('./template');
  20
  21 // For logging.
  22 const _fileScope = common.fileScope(__filename);
  23
  24 const defaultOptions = {
  25   ignoreTrailingSlash: false,
  26   proxyPrefix: '',
  27   strictAccept: true,
  28   selfBaseUrl: '',
  29   staticMetadata: true,
  30   staticPath: undefined, // no reasonable default
  31   trustProxy: true,
  32   querystring,
  33 };
  34
  35 class Dingus {
  36   /**
  37    * @param {Object} logger object which implements logging methods
  38    * @param {Object} options
  39    * @param {Boolean} options.ignoreTrailingSlash
  40    * @param {string} options.proxyPrefix leading part of url path to strip
  41    * @param {Boolean} options.strictAccept whether to error on unsupported Accept type
  42    * @param {string} options.selfBaseUrl for constructing links
  43    * @param {Boolean} options.staticMetadata serve static headers with static files
  44    * @param {Boolean} options.trustProxy trust some header data to be provided by proxy
  45    * @param {Object} options.querystring alternate qs parser to use
  46    */
  47   constructor(logger = common.nullLogger, options = {}) {
  48     common.setOptions(this, defaultOptions, options);
  49
  50     this.router = new Router(options);
  51
  52     if (!this.proxyPrefix) {
  53       this._stripPrefix = (p) => p;
  54     }
  55
  56     this.responseTypes = [
  57       Enum.ContentType.TextHTML,
  58       Enum.ContentType.TextPlain,
  59       Enum.ContentType.ApplicationJson,
  60     ];
  61
  62     this.logger = logger;
  63     common.ensureLoggerLevels(this.logger);
  64   }
  65
  66
  67   /**
  68    * Resolve relative and empty paths in url
  69    * @param {string} p path
  70    */
  71   _normalizePath(p) {
  72     const pathNorm = path.normalize(p); // This isn't perfectly correct, but it's easy...
  73     return this._stripPrefix(pathNorm);
  74   }
  75
  76
  77   /**
  78    * Remove a leading portion of url path
  79    * N.B. This method gets obliterated if there is no prefix defined at construction
  80    * @param {string} p path
  81    */
  82   _stripPrefix(p) {
  83     if (p.startsWith(this.proxyPrefix)) {
  84       return p.slice(this.proxyPrefix.length);
  85     }
  86     return p;
  87   }
  88
  89
  90   /**
  91    * Returns the path part, and querystring object, from a request url.
  92    * @param {string} url
  93    */
  94   _splitUrl(url) {
  95     const [ p, qs ] = common.splitFirst(url, '?');
  96     return {
  97       pathPart: this._normalizePath(p),
  98       queryParams: this.querystring.parse(qs),
  99     };
 100   }
 101
 102
 103   /**
 104    * Insert a new path handler
 105    * @param {string} method
 106    * @param {string} urlPath
 107    * @param {fn} handler
 108    */
 109   on(method, urlPath, handler, ...handlerArgs) {
 110     this.router.on(method, urlPath, handler, handlerArgs);
 111   }
 112
 113
 114   /**
 115    * Common header tagging for all requests.
 116    * Add our own identifier, and persist any external transit identifiers.
 117    * @param {http.ClientRequest} req
 118    * @param {http.ServerResponse} res
 119    * @param {object} ctx
 120    */
 121   static tagContext(req, res, ctx) {
 122     const requestId = common.requestId();
 123     ctx.requestId = requestId;
 124     res.setHeader(Enum.Header.RequestId, requestId);
 125     [Enum.Header.XRequestId, Enum.Header.XCorrelationId].forEach((h) => {
 126       const v = req.getHeader(h);
 127       if (v) {
 128         ctx[h.replace(/-/g, '')] = v;
 129         res.setHeader(h, v);
 130       }
 131     });
 132     return requestId;
 133   }
 134
 135
 136   /**
 137    *
 138    * @param {http.ClientRequest} req
 139    */
 140   _getAddress(req) {
 141     // TODO: RFC7239 Forwarded support
 142     const address = (this.trustProxy && req && req.getHeader(Enum.Header.XForwardedFor)) ||
 143       (this.trustProxy && req && req.getHeader(Enum.Header.XRealIP)) ||
 144       (req && req.connection && req.connection.remoteAddress) ||
 145       '';
 146     return address.split(/\s*,\s*/u)[0];
 147   }
 148
 149
 150   /**
 151    *
 152    * @param {http.ClientRequest} req
 153    */
 154   _getProtocol(req) {
 155     // TODO: RFC7239 Forwarded support
 156     const protocol = (this.trustProxy && req && req.getHeader(Enum.Header.XForwardedProto)) ||
 157       ((req && req.connection && req.connection.encrypted) ? 'https' : 'http');
 158     return protocol.split(/\s*,\s*/u)[0];
 159   }
 160
 161
 162   /**
 163    *
 164    * @param {http.ClientRequest} req
 165    * @param {http.ServerResponse} res
 166    * @param {object} ctx
 167    */
 168   clientAddressContext(req, res, ctx) {
 169     ctx.clientAddress = this._getAddress(req);
 170     ctx.clientProtocol = this._getProtocol(req);
 171   }
 172
 173
 174   /**
 175    * Called before every request handler.
 176    * @param {http.ClientRequest} req
 177    * @param {http.ServerResponse} res
 178    * @param {object} ctx
 179    */
 180   async preHandler(req, res, ctx) {
 181     Dingus.tagContext(req, res, ctx);
 182     this.clientAddressContext(req, res, ctx);
 183   }
 184
 185
 186   /**
 187    * Helper for collecting chunks as array of buffers.
 188    * @param {Buffer[]} chunks
 189    * @param {string|Buffer} chunk
 190    * @param {string} encoding
 191    */
 192   static pushBufChunk(chunks, chunk, encoding = 'utf8') {
 193     if (chunk) {
 194       if (typeof chunk === 'string') {
 195         chunk = Buffer.from(chunk, encoding);
 196       }
 197       chunks.push(chunk);
 198     }
 199   }
 200
 201
 202   /**
 203    * Sets ctx.responseBody and calls handler upon res.end().
 204    * @param {http.ClientRequest} req
 205    * @param {http.ServerResponse} res
 206    * @param {object} ctx
 207    * @param {*} handler fn(req, res, ctx)
 208    */
 209   static setEndBodyHandler(req, res, ctx, handler) {
 210     const origWrite = res.write.bind(res);
 211     const origEnd = res.end.bind(res);
 212     const chunks = [];
 213     res.write = function (chunk, encoding, ...rest) {
 214       Dingus.pushBufChunk(chunks, chunk, encoding);
 215       return origWrite(chunk, encoding, ...rest);
 216     };
 217     res.end = function (data, encoding, ...rest) {
 218       Dingus.pushBufChunk(chunks, data, encoding);
 219       ctx.responseBody = Buffer.concat(chunks);
 220       handler(req, res, ctx);
 221       return origEnd(data, encoding, ...rest);
 222     };
 223   }
 224
 225
 226   /**
 227    * Intercept writes for head requests, do not send to client,
 228    * but send length, and make body available in context.
 229    * N.B. If persisted, ctx.responseBody will be a raw buffer, be aware when logging.
 230    * @param {http.ClientRequest} req
 231    * @param {http.ServerResponse} res
 232    * @param {object} ctx
 233    * @param {Boolean} persistResponseBody
 234    */
 235   static setHeadHandler(req, res, ctx, persistResponseBody = false) {
 236     if (req.method === 'HEAD') {
 237       const origEnd = res.end.bind(res);
 238       const chunks = [];
 239       res.write = function (chunk, encoding) {
 240         Dingus.pushBufChunk(chunks, chunk, encoding);
 241         // No call to original res.write.
 242       };
 243       res.end = function (data, encoding, ...rest) {
 244         Dingus.pushBufChunk(chunks, data, encoding);
 245         const responseBody = Buffer.concat(chunks);
 246         res.setHeader(Enum.Header.ContentLength, Buffer.byteLength(responseBody));
 247         if (persistResponseBody) {
 248           ctx.responseBody = responseBody;
 249         }
 250         return origEnd(undefined, encoding, ...rest);
 251       };
 252     }
 253   }
 254
 255
 256   /**
 257    * Dispatch the handler for a request
 258    * @param {http.ClientRequest} req
 259    * @param {http.ServerResponse} res
 260    * @param {object} ctx
 261    */
 262   async dispatch(req, res, ctx = {}) {
 263     const _scope = _fileScope('dispatch');
 264
 265     const { pathPart, queryParams } = this._splitUrl(req.url);
 266     ctx.queryParams = queryParams;
 267
 268     let handler, handlerArgs = [];
 269     try {
 270       ({ handler, handlerArgs } = this.router.lookup(req.method, pathPart, ctx));
 271     } catch (e) {
 272       if (e instanceof DingusError) {
 273         switch (e.message) {
 274           case 'NoPath':
 275             handler = this.handlerNotFound.bind(this);
 276             break;
 277           case 'NoMethod':
 278             handler = this.handlerMethodNotAllowed.bind(this);
 279             break;
 280           default:
 281             this.logger.error(_scope, 'unknown dingus error', { error: e });
 282             handler = this.handlerInternalServerError.bind(this);
 283         }
 284       } else if (e instanceof URIError) {
 285         handler = this.handlerBadRequest.bind(this);
 286       } else {
 287         this.logger.error(_scope, 'lookup failure', { error: e });
 288         handler = this.handlerInternalServerError.bind(this);
 289       }
 290     }
 291
 292     try {
 293       await this.preHandler(req, res, ctx);
 294       return await handler(req, res, ctx, ...handlerArgs);
 295     } catch (e) {
 296       ctx.error = e;
 297       this.sendErrorResponse(e, req, res, ctx);
 298     }
 299   }
 300
 301
 302   /**
 303    * Return normalized type, without any parameters.
 304    * @param {http.ClientRequest} req
 305    * @returns {string}
 306    */
 307   static getRequestContentType(req) {
 308     const contentType = req.getHeader(Enum.Header.ContentType);
 309     return (contentType || '').split(';')[0].trim().toLowerCase();
 310   }
 311
 312
 313   /**
 314    * Parse rawBody from ctx as contentType into parsedBody.
 315    * @param {string} contentType
 316    * @param {object} ctx
 317    */
 318   parseBody(contentType, ctx) {
 319     const _scope = _fileScope('parseBody');
 320
 321     switch (contentType) {
 322       case Enum.ContentType.ApplicationForm:
 323         ctx.parsedBody = this.querystring.parse(ctx.rawBody);
 324         break;
 325
 326       case Enum.ContentType.ApplicationJson:
 327         try {
 328           ctx.parsedBody = JSON.parse(ctx.rawBody);
 329         } catch (e) {
 330           this.logger.debug(_scope, 'JSON parse failed', { requestId: ctx.requestId, error: e });
 331           throw new ResponseError(Enum.ErrorResponse.BadRequest, e.message);
 332         }
 333         break;
 334
 335       default:
 336         this.logger.debug(_scope, 'unhandled content-type', { requestId: ctx.requestId, contentType });
 337         throw new ResponseError(Enum.ErrorResponse.UnsupportedMediaType);
 338     }
 339   }
 340
 341
 342   /**
 343    * Return all body data from a request.
 344    * @param {http.ClientRequest} req
 345    * @param {Number=} maximumBodySize
 346    */
 347   async bodyData(req, maximumBodySize) {
 348     const _scope = _fileScope('bodyData');
 349     return new Promise((resolve, reject) => {
 350       const body = [];
 351       let length = 0;
 352       req.on('data', (chunk) => {
 353         body.push(chunk);
 354         length += Buffer.byteLength(chunk);
 355         if (maximumBodySize && length > maximumBodySize) {
 356           this.logger.debug(_scope, 'body data exceeded limit', { length, maximumBodySize });
 357           reject(new ResponseError(Enum.ErrorResponse.RequestEntityTooLarge));
 358         }
 359       });
 360       req.on('end', () => resolve(Buffer.concat(body).toString()));
 361       req.on('error', (e) => {
 362         this.logger.error(_scope, 'failed', { error: e });
 363         reject(e);
 364       });
 365     });
 366   }
 367
 368
 369   /**
 370    * Read and parse request body data.
 371    * @param {http.ClientRequest} req
 372    * @param {http.ServerResponse} res
 373    * @param {object} ctx
 374    */
 375   async ingestBody(req, res, ctx) {
 376     ctx.rawBody = await this.bodyData(req);
 377     const contentType = Dingus.getRequestContentType(req);
 378     this.parseBody(contentType, ctx);
 379   }
 380
 381
 382   /**
 383    * Return the best matching response type.
 384    * @param {string[]} responseTypes
 385    * @param {http.ClientRequest} req
 386    */
 387   static getResponseContentType(responseTypes, req) {
 388     const acceptHeader = req.getHeader(Enum.Header.Accept);
 389     return ContentNegotiation.accept(responseTypes, acceptHeader);
 390   }
 391
 392
 393   /**
 394    * Returns a list of the most-preferred content encodings for the response.
 395    * @param {string[]} responseEncodings
 396    * @param {http.ClientRequest} req
 397    */
 398   static getResponseEncoding(responseEncodings, req) {
 399     const acceptEncodingHeader = req.getHeader(Enum.Header.AcceptEncoding);
 400     return ContentNegotiation.preferred(responseEncodings, acceptEncodingHeader);
 401   }
 402
 403
 404   /**
 405    * Set the best content type for the response.
 406    * @param {string[]} responseTypes default first
 407    * @param {http.ClientRequest} req
 408    * @param {http.ServerResponse} res
 409    * @param {object} ctx
 410    */
 411   setResponseType(responseTypes, req, res, ctx) {
 412     const _scope = _fileScope('setResponseType');
 413     ctx.responseType = Dingus.getResponseContentType(responseTypes, req);
 414     if (!ctx.responseType) {
 415       if (this.strictAccept) {
 416         this.logger.debug(_scope, 'unhandled strict accept', { requestId: req.requestId });
 417         throw new ResponseError(Enum.ErrorResponse.NotAcceptable);
 418       } else {
 419         ctx.responseType = responseTypes[0];
 420       }
 421     }
 422     res.setHeader(Enum.Header.ContentType, ctx.responseType);
 423   }
 424
 425
 426   /**
 427    * Inserts an encoding
 428    * @param {http.ServerResponse} res
 429    * @param {string} encoding
 430    */
 431   static addEncodingHeader(res, encoding) {
 432     const existingEncodings = res.getHeader(Enum.Header.ContentEncoding);
 433     if (existingEncodings) {
 434       encoding = `${encoding}, ${existingEncodings}`;
 435     }
 436     res.setHeader(Enum.Header.ContentEncoding, encoding);
 437   }
 438
 439
 440   /**
 441    * Attempt to fetch both data and metadata for a file.
 442    * @param {string} filePath
 443    */
 444   async _readFileInfo(filePath) {
 445     const _scope = _fileScope('_readFileInfo');
 446     let result;
 447     try {
 448       // eslint-disable-next-line security/detect-non-literal-fs-filename
 449       const stat = fsPromises.stat(filePath);
 450       // eslint-disable-next-line security/detect-non-literal-fs-filename
 451       const data = fsPromises.readFile(filePath);
 452       result = await Promise.all([stat, data]);
 453     } catch (e) {
 454       if (['ENOENT', 'EACCES', 'EISDIR', 'ENAMETOOLONG', 'EINVAL'].includes(e.code)) {
 455         return [null, null];
 456       }
 457       this.logger.error(_scope, 'fs error', { error: e, filePath });
 458       throw e;
 459     }
 460     return result;
 461   }
 462
 463
 464   /**
 465    * Potentially add additional headers from static file meta-file.
 466    * @param {http.ServerResponse} res
 467    * @param {string} directory
 468    * @param {string} fileName - already normalized and filtered
 469    */
 470   async _serveFileMetaHeaders(res, directory, fileName) {
 471     const _scope = _fileScope('_serveFileMetaHeaders');
 472     this.logger.debug(_scope, 'called', { directory, fileName });
 473
 474     const metaPrefix = '.';
 475     const metaSuffix = '.meta';
 476     const metaFileName = `${metaPrefix}${fileName}${metaSuffix}`;
 477     const metaFilePath = path.join(directory, metaFileName);
 478
 479     const [stat, data] = await this._readFileInfo(metaFilePath);
 480     if (!stat) {
 481       return;
 482     }
 483
 484     const lineBreakRE = /\r\n|\n|\r/;
 485     const lines = data.toString().split(lineBreakRE);
 486     common.unfoldHeaderLines(lines);
 487
 488     const headerParseRE = /^(?<name>[^:]+): +(?<value>.*)$/;
 489     lines.forEach((line) => {
 490       if (line) {
 491         const result = headerParseRE.exec(line);
 492         const { groups: header } = result;
 493         res.setHeader(header.name, header.value);
 494       }
 495     });
 496   }
 497
 498
 499   /**
 500    * Serve a file from a directory, with rudimentary cache awareness.
 501    * This will also serve pre-encoded variations if available and requested.
 502    * @param {http.ClientRequest} req
 503    * @param {http.ServerResponse} res
 504    * @param {object} ctx
 505    * @param {string} directory
 506    * @param {string} fileName
 507    */
 508   async serveFile(req, res, ctx, directory, fileName) {
 509     const _scope = _fileScope('serveFile');
 510     this.logger.debug(_scope, 'called', { req: common.requestLogData(req), ctx });
 511
 512     // Require a directory field.
 513     if (!directory) {
 514       this.logger.debug(_scope, 'rejected unset directory', { fileName });
 515       return this.handlerNotFound(req, res, ctx);
 516     }
 517
 518     // Normalize the supplied path, as encoded path-navigation may have been (maliciously) present.
 519     fileName = path.normalize(fileName);
 520
 521     // We will not deal with any subdirs, nor any dot-files.
 522     // (Note that we could not deal with subdirs even if we wanted, due to simple router matching scheme.)
 523     if (fileName.indexOf(path.sep) >= 0
 524     ||  fileName.charAt(0) === '.') {
 525       this.logger.debug(_scope, 'rejected filename', { fileName });
 526       return this.handlerNotFound(req, res, ctx);
 527     }
 528
 529     const filePath = path.join(directory, fileName);
 530
 531     // File must exist, before any alternate static encodings will be considered.
 532     let [stat, data] = await this._readFileInfo(filePath);
 533     if (!stat) {
 534       return this.handlerNotFound(req, res, ctx);
 535     }
 536
 537     // If encodings were requested, check for static versions to serve.
 538     // Update stat and data if matching version is found.
 539     ctx.availableEncodings = Dingus.getResponseEncoding(Object.values(Enum.EncodingType), req);
 540     if (ctx.availableEncodings.length === 0) {
 541       // Identity encoding was specifically denied, and nothing else available.
 542       this.logger.debug(_scope, 'no suitable encodings', { ctx });
 543       return this.handlerMethodNotAllowed(req, res, ctx);
 544     }
 545     for (const encoding of ctx.availableEncodings) {
 546       if (encoding === Enum.EncodingType.Identity) {
 547         break;
 548       }
 549       const suffix = Enum.EncodingTypeSuffix[encoding];
 550       if (suffix) {
 551         const encodedFilePath = `${filePath}${suffix}`;
 552         const [ encodedStat, encodedData ] = await this._readFileInfo(encodedFilePath);
 553         if (encodedStat) {
 554           ([ stat, data ] = [ encodedStat, encodedData ]);
 555           ctx.selectedEncoding = encoding;
 556           Dingus.addEncodingHeader(res, encoding);
 557           res.setHeader(Enum.Header.Vary, Enum.Header.AcceptEncoding);
 558           this.logger.debug(_scope, 'serving encoded version', { ctx, encodedFilePath });
 559         }
 560         break;
 561       }
 562     }
 563
 564     const lastModifiedDate = new Date(stat.mtimeMs);
 565     res.setHeader(Enum.Header.LastModified, lastModifiedDate.toGMTString());
 566
 567     const eTag = common.generateETag(filePath, stat, data);
 568     res.setHeader(Enum.Header.ETag, eTag);
 569
 570     if (common.isClientCached(req, stat.mtimeMs, eTag)) {
 571       this.logger.debug(_scope, 'client cached file', { filePath });
 572       res.statusCode = 304; // Not Modified
 573       res.end();
 574       return;
 575     }
 576
 577     // Set the type based on extension of un-encoded filename.
 578     const ext = path.extname(filePath).slice(1); // Drop the dot
 579     const contentType = extensionToMime(ext);
 580     res.setHeader(Enum.Header.ContentType, contentType);
 581
 582     // We presume static files are relatively cacheable.
 583     res.setHeader(Enum.Header.CacheControl, 'public');
 584
 585     if (this.staticMetadata) {
 586       await this._serveFileMetaHeaders(res, directory, fileName);
 587     }
 588
 589     this.logger.debug(_scope, 'serving file', { filePath, contentType });
 590     res.end(data);
 591   }
 592
 593
 594   /**
 595    * Return a content-type appropriate rendering of an errorResponse object.
 596    * @param {string} type content-type of response
 597    * @param {object} err either an Error object, or an error response
 598    * @param {number} err.statusCode
 599    * @param {string} err.errorMessage
 600    * @param {string|string[]} err.details
 601    */
 602   // eslint-disable-next-line class-methods-use-this
 603   renderError(contentType, err) {
 604     switch (contentType) {
 605       case Enum.ContentType.ApplicationJson:
 606         return JSON.stringify(err);
 607
 608       case Enum.ContentType.TextHTML:
 609         return Template.errorHTML(err);
 610
 611       case Enum.ContentType.TextPlain:
 612       default:
 613         return [err.errorMessage, err.details].join('\r\n');
 614     }
 615   }
 616
 617
 618   /**
 619    * Send an error response.  Terminal.
 620    * Logs any non-error-response errors as such.
 621    * @param {object} err either an Error object, or an error response
 622    * @param {http.ClientRequest} req
 623    * @param {http.ServerResponse} res
 624    * @param {object} ctx
 625    */
 626   sendErrorResponse(err, req, res, ctx) {
 627     const _scope = _fileScope('sendErrorResponse');
 628     let body;
 629
 630     // Default to a content type if one is not yet present
 631     if (!res.hasHeader(Enum.Header.ContentType)) {
 632       res.setHeader(Enum.Header.ContentType, Enum.ContentType.TextPlain);
 633     }
 634
 635     if (err && err.statusCode) {
 636       res.statusCode = err.statusCode;
 637       body = this.renderError(res.getHeader(Enum.Header.ContentType), err);
 638       this.logger.debug(_scope, 'handler error', { err, ...common.handlerLogData(req, res, ctx) });
 639     } else {
 640       res.statusCode = 500;
 641       body = this.renderError(res.getHeader(Enum.Header.ContentType), Enum.ErrorResponse.InternalServerError);
 642       this.logger.error(_scope, 'handler exception', { err, ...common.handlerLogData(req, res, ctx) });
 643     }
 644     res.end(body);
 645   }
 646
 647
 648   /**
 649    * @param {http.ClientRequest} req
 650    * @param {http.ServerResponse} res
 651    * @param {object} ctx
 652    * @param {String} file - override ctx.params.file
 653    */
 654   async handlerGetStaticFile(req, res, ctx, file) {
 655     Dingus.setHeadHandler(req, res, ctx);
 656
 657     // Set a default response type to handle any errors; will be re-set to serve actual static content type.
 658     this.setResponseType(this.responseTypes, req, res, ctx);
 659
 660     await this.serveFile(req, res, ctx, this.staticPath, file || ctx.params.file);
 661   }
 662
 663
 664   /**
 665    * @param {http.ClientRequest} req
 666    * @param {http.ServerResponse} res
 667    * @param {Object} ctx
 668    * @param {String} newPath
 669    * @param {Number} statusCode
 670   */
 671   async handlerRedirect(req, res, ctx, newPath, statusCode = 307) {
 672     this.setResponseType(this.responseTypes, req, res, ctx);
 673     res.setHeader(Enum.Header.Location, newPath);
 674     res.statusCode = statusCode;
 675     res.end();
 676   }
 677
 678
 679   /**
 680    * @param {http.ClientRequest} req
 681    * @param {http.ServerResponse} res
 682    * @param {object} ctx
 683    */
 684   async handlerMethodNotAllowed(req, res, ctx) {
 685     this.setResponseType(this.responseTypes, req, res, ctx);
 686     throw new ResponseError(Enum.ErrorResponse.MethodNotAllowed);
 687   }
 688
 689
 690   /**
 691    * @param {http.ClientRequest} req
 692    * @param {http.ServerResponse} res
 693    * @param {object} ctx
 694    */
 695   async handlerNotFound(req, res, ctx) {
 696     this.setResponseType(this.responseTypes, req, res, ctx);
 697     throw new ResponseError(Enum.ErrorResponse.NotFound);
 698   }
 699
 700
 701   /**
 702    * @param {http.ClientRequest} req
 703    * @param {http.ServerResponse} res
 704    * @param {object} ctx
 705    */
 706   async handlerBadRequest(req, res, ctx) {
 707     this.setResponseType(this.responseTypes, req, res, ctx);
 708     throw new ResponseError(Enum.ErrorResponse.BadRequest);
 709   }
 710
 711
 712   /**
 713    * @param {http.ClientRequest} req
 714    * @param {http.ServerResponse} res
 715    * @param {object} ctx
 716    */
 717   async handlerInternalServerError(req, res, ctx) {
 718     this.setResponseType(this.responseTypes, req, res, ctx);
 719     throw new ResponseError(Enum.ErrorResponse.InternalServerError);
 720   }
 721
 722 }
 723
 724 module.exports = Dingus;