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    * @param {http.ClientRequest} req
 230    * @param {http.ServerResponse} res
 231    * @param {object} ctx
 232    */
 233   static setHeadHandler(req, res, ctx) {
 234     if (req.method === 'HEAD') {
 235       const origEnd = res.end.bind(res);
 236       const chunks = [];
 237       res.write = function (chunk, encoding) {
 238         Dingus.pushBufChunk(chunks, chunk, encoding);
 239         // No call to original res.write.
 240       };
 241       res.end = function (data, encoding, ...rest) {
 242         Dingus.pushBufChunk(chunks, data, encoding);
 243         ctx.responseBody = Buffer.concat(chunks);
 244         res.setHeader(Enum.Header.ContentLength, Buffer.byteLength(ctx.responseBody));
 245         return origEnd(undefined, encoding, ...rest);
 246       };
 247     }
 248   }
 249
 250
 251   /**
 252    * Dispatch the handler for a request
 253    * @param {http.ClientRequest} req
 254    * @param {http.ServerResponse} res
 255    * @param {object} ctx
 256    */
 257   async dispatch(req, res, ctx = {}) {
 258     const _scope = _fileScope('dispatch');
 259
 260     const { pathPart, queryParams } = this._splitUrl(req.url);
 261     ctx.queryParams = queryParams;
 262
 263     let handler, handlerArgs = [];
 264     try {
 265       ({ handler, handlerArgs } = this.router.lookup(req.method, pathPart, ctx));
 266     } catch (e) {
 267       if (e instanceof DingusError) {
 268         switch (e.message) {
 269           case 'NoPath':
 270             handler = this.handlerNotFound.bind(this);
 271             break;
 272           case 'NoMethod':
 273             handler = this.handlerMethodNotAllowed.bind(this);
 274             break;
 275           default:
 276             this.logger.error(_scope, 'unknown dingus error', { error: e });
 277             handler = this.handlerInternalServerError.bind(this);
 278         }
 279       } else if (e instanceof URIError) {
 280         handler = this.handlerBadRequest.bind(this);
 281       } else {
 282         this.logger.error(_scope, 'lookup failure', { error: e });
 283         handler = this.handlerInternalServerError.bind(this);
 284       }
 285     }
 286
 287     try {
 288       await this.preHandler(req, res, ctx);
 289       return await handler(req, res, ctx, ...handlerArgs);
 290     } catch (e) {
 291       ctx.error = e;
 292       this.sendErrorResponse(e, req, res, ctx);
 293     }
 294   }
 295
 296
 297   /**
 298    * Return normalized type, without any parameters.
 299    * @param {http.ClientRequest} req
 300    * @returns {string}
 301    */
 302   static getRequestContentType(req) {
 303     const contentType = req.getHeader(Enum.Header.ContentType);
 304     return (contentType || '').split(';')[0].trim().toLowerCase();
 305   }
 306
 307
 308   /**
 309    * Parse rawBody from ctx as contentType into parsedBody.
 310    * @param {string} contentType
 311    * @param {object} ctx
 312    */
 313   parseBody(contentType, ctx) {
 314     const _scope = _fileScope('parseBody');
 315
 316     switch (contentType) {
 317       case Enum.ContentType.ApplicationForm:
 318         ctx.parsedBody = this.querystring.parse(ctx.rawBody);
 319         break;
 320
 321       case Enum.ContentType.ApplicationJson:
 322         try {
 323           ctx.parsedBody = JSON.parse(ctx.rawBody);
 324         } catch (e) {
 325           this.logger.debug(_scope, 'JSON parse failed', { requestId: ctx.requestId, error: e });
 326           throw new ResponseError(Enum.ErrorResponse.BadRequest, e.message);
 327         }
 328         break;
 329
 330       default:
 331         this.logger.debug(_scope, 'unhandled content-type', { requestId: ctx.requestId, contentType });
 332         throw new ResponseError(Enum.ErrorResponse.UnsupportedMediaType);
 333     }
 334   }
 335
 336
 337   /**
 338    * Return all body data from a request.
 339    * @param {http.ClientRequest} req
 340    * @param {Number=} maximumBodySize
 341    */
 342   async bodyData(req, maximumBodySize) {
 343     const _scope = _fileScope('bodyData');
 344     return new Promise((resolve, reject) => {
 345       const body = [];
 346       let length = 0;
 347       req.on('data', (chunk) => {
 348         body.push(chunk);
 349         length += Buffer.byteLength(chunk);
 350         if (maximumBodySize && length > maximumBodySize) {
 351           this.logger.debug(_scope, 'body data exceeded limit', { length, maximumBodySize });
 352           reject(new ResponseError(Enum.ErrorResponse.RequestEntityTooLarge));
 353         }
 354       });
 355       req.on('end', () => resolve(Buffer.concat(body).toString()));
 356       req.on('error', (e) => {
 357         this.logger.error(_scope, 'failed', { error: e });
 358         reject(e);
 359       });
 360     });
 361   }
 362
 363
 364   /**
 365    * Read and parse request body data.
 366    * @param {http.ClientRequest} req
 367    * @param {http.ServerResponse} res
 368    * @param {object} ctx
 369    */
 370   async ingestBody(req, res, ctx) {
 371     ctx.rawBody = await this.bodyData(req);
 372     const contentType = Dingus.getRequestContentType(req);
 373     this.parseBody(contentType, ctx);
 374   }
 375
 376
 377   /**
 378    * Return the best matching response type.
 379    * @param {string[]} responseTypes
 380    * @param {http.ClientRequest} req
 381    */
 382   static getResponseContentType(responseTypes, req) {
 383     const acceptHeader = req.getHeader(Enum.Header.Accept);
 384     return ContentNegotiation.accept(responseTypes, acceptHeader);
 385   }
 386
 387
 388   /**
 389    * Returns a list of the most-preferred content encodings for the response.
 390    * @param {string[]} responseEncodings
 391    * @param {http.ClientRequest} req
 392    */
 393   static getResponseEncoding(responseEncodings, req) {
 394     const acceptEncodingHeader = req.getHeader(Enum.Header.AcceptEncoding);
 395     return ContentNegotiation.preferred(responseEncodings, acceptEncodingHeader);
 396   }
 397
 398
 399   /**
 400    * Set the best content type for the response.
 401    * @param {string[]} responseTypes default first
 402    * @param {http.ClientRequest} req
 403    * @param {http.ServerResponse} res
 404    * @param {object} ctx
 405    */
 406   setResponseType(responseTypes, req, res, ctx) {
 407     const _scope = _fileScope('setResponseType');
 408     ctx.responseType = Dingus.getResponseContentType(responseTypes, req);
 409     if (!ctx.responseType) {
 410       if (this.strictAccept) {
 411         this.logger.debug(_scope, 'unhandled strict accept', { requestId: req.requestId });
 412         throw new ResponseError(Enum.ErrorResponse.NotAcceptable);
 413       } else {
 414         ctx.responseType = responseTypes[0];
 415       }
 416     }
 417     res.setHeader(Enum.Header.ContentType, ctx.responseType);
 418   }
 419
 420
 421   /**
 422    * Inserts an encoding
 423    * @param {http.ServerResponse} res
 424    * @param {string} encoding
 425    */
 426   static addEncodingHeader(res, encoding) {
 427     const existingEncodings = res.getHeader(Enum.Header.ContentEncoding);
 428     if (existingEncodings) {
 429       encoding = `${encoding}, ${existingEncodings}`;
 430     }
 431     res.setHeader(Enum.Header.ContentEncoding, encoding);
 432   }
 433
 434
 435   /**
 436    * Attempt to fetch both data and metadata for a file.
 437    * @param {string} filePath
 438    */
 439   async _readFileInfo(filePath) {
 440     const _scope = _fileScope('_readFileInfo');
 441     let result;
 442     try {
 443       // eslint-disable-next-line security/detect-non-literal-fs-filename
 444       const stat = fsPromises.stat(filePath);
 445       // eslint-disable-next-line security/detect-non-literal-fs-filename
 446       const data = fsPromises.readFile(filePath);
 447       result = await Promise.all([stat, data]);
 448     } catch (e) {
 449       if (['ENOENT', 'EACCES', 'EISDIR', 'ENAMETOOLONG', 'EINVAL'].includes(e.code)) {
 450         return [null, null];
 451       }
 452       this.logger.error(_scope, 'fs error', { error: e, filePath });
 453       throw e;
 454     }
 455     return result;
 456   }
 457
 458
 459   /**
 460    * Potentially add additional headers from static file meta-file.
 461    * @param {http.ServerResponse} res
 462    * @param {string} directory
 463    * @param {string} fileName - already normalized and filtered
 464    */
 465   async _serveFileMetaHeaders(res, directory, fileName) {
 466     const _scope = _fileScope('_serveFileMetaHeaders');
 467     this.logger.debug(_scope, 'called', { directory, fileName });
 468
 469     const metaPrefix = '.';
 470     const metaSuffix = '.meta';
 471     const metaFileName = `${metaPrefix}${fileName}${metaSuffix}`;
 472     const metaFilePath = path.join(directory, metaFileName);
 473
 474     const [stat, data] = await this._readFileInfo(metaFilePath);
 475     if (!stat) {
 476       return;
 477     }
 478
 479     const lineBreakRE = /\r\n|\n|\r/;
 480     const lines = data.toString().split(lineBreakRE);
 481     common.unfoldHeaderLines(lines);
 482
 483     const headerParseRE = /^(?<name>[^:]+): +(?<value>.*)$/;
 484     lines.forEach((line) => {
 485       if (line) {
 486         const result = headerParseRE.exec(line);
 487         const { groups: header } = result;
 488         res.setHeader(header.name, header.value);
 489       }
 490     });
 491   }
 492
 493
 494   /**
 495    * Serve a file from a directory, with rudimentary cache awareness.
 496    * This will also serve pre-encoded variations if available and requested.
 497    * @param {http.ClientRequest} req
 498    * @param {http.ServerResponse} res
 499    * @param {object} ctx
 500    * @param {string} directory
 501    * @param {string} fileName
 502    */
 503   async serveFile(req, res, ctx, directory, fileName) {
 504     const _scope = _fileScope('serveFile');
 505     this.logger.debug(_scope, 'called', { req: common.requestLogData(req), ctx });
 506
 507     // Require a directory field.
 508     if (!directory) {
 509       this.logger.debug(_scope, 'rejected unset directory', { fileName });
 510       return this.handlerNotFound(req, res, ctx);
 511     }
 512
 513     // Normalize the supplied path, as encoded path-navigation may have been (maliciously) present.
 514     fileName = path.normalize(fileName);
 515
 516     // We will not deal with any subdirs, nor any dot-files.
 517     // (Note that we could not deal with subdirs even if we wanted, due to simple router matching scheme.)
 518     if (fileName.indexOf(path.sep) >= 0
 519     ||  fileName.charAt(0) === '.') {
 520       this.logger.debug(_scope, 'rejected filename', { fileName });
 521       return this.handlerNotFound(req, res, ctx);
 522     }
 523
 524     const filePath = path.join(directory, fileName);
 525
 526     // File must exist, before any alternate static encodings will be considered.
 527     let [stat, data] = await this._readFileInfo(filePath);
 528     if (!stat) {
 529       return this.handlerNotFound(req, res, ctx);
 530     }
 531
 532     // If encodings were requested, check for static versions to serve.
 533     // Update stat and data if matching version is found.
 534     ctx.availableEncodings = Dingus.getResponseEncoding(Object.values(Enum.EncodingType), req);
 535     if (ctx.availableEncodings.length === 0) {
 536       // Identity encoding was specifically denied, and nothing else available.
 537       this.logger.debug(_scope, 'no suitable encodings', { ctx });
 538       return this.handlerMethodNotAllowed(req, res, ctx);
 539     }
 540     for (const encoding of ctx.availableEncodings) {
 541       if (encoding === Enum.EncodingType.Identity) {
 542         break;
 543       }
 544       const suffix = Enum.EncodingTypeSuffix[encoding];
 545       if (suffix) {
 546         const encodedFilePath = `${filePath}${suffix}`;
 547         const [ encodedStat, encodedData ] = await this._readFileInfo(encodedFilePath);
 548         if (encodedStat) {
 549           ([ stat, data ] = [ encodedStat, encodedData ]);
 550           ctx.selectedEncoding = encoding;
 551           Dingus.addEncodingHeader(res, encoding);
 552           res.setHeader(Enum.Header.Vary, Enum.Header.AcceptEncoding);
 553           this.logger.debug(_scope, 'serving encoded version', { ctx, encodedFilePath });
 554         }
 555         break;
 556       }
 557     }
 558
 559     const lastModifiedDate = new Date(stat.mtimeMs);
 560     res.setHeader(Enum.Header.LastModified, lastModifiedDate.toGMTString());
 561
 562     const eTag = common.generateETag(filePath, stat, data);
 563     res.setHeader(Enum.Header.ETag, eTag);
 564
 565     if (common.isClientCached(req, stat.mtimeMs, eTag)) {
 566       this.logger.debug(_scope, 'client cached file', { filePath });
 567       res.statusCode = 304; // Not Modified
 568       res.end();
 569       return;
 570     }
 571
 572     // Set the type based on extension of un-encoded filename.
 573     const ext = path.extname(filePath).slice(1); // Drop the dot
 574     const contentType = extensionToMime(ext);
 575     res.setHeader(Enum.Header.ContentType, contentType);
 576
 577     // We presume static files are relatively cacheable.
 578     res.setHeader(Enum.Header.CacheControl, 'public');
 579
 580     if (this.staticMetadata) {
 581       await this._serveFileMetaHeaders(res, directory, fileName);
 582     }
 583
 584     this.logger.debug(_scope, 'serving file', { filePath, contentType });
 585     res.end(data);
 586   }
 587
 588
 589   /**
 590    * Return a content-type appropriate rendering of an errorResponse object.
 591    * @param {string} type content-type of response
 592    * @param {object} err either an Error object, or an error response
 593    * @param {number} err.statusCode
 594    * @param {string} err.errorMessage
 595    * @param {string|string[]} err.details
 596    */
 597   // eslint-disable-next-line class-methods-use-this
 598   renderError(contentType, err) {
 599     switch (contentType) {
 600       case Enum.ContentType.ApplicationJson:
 601         return JSON.stringify(err);
 602
 603       case Enum.ContentType.TextHTML:
 604         return Template.errorHTML(err);
 605
 606       case Enum.ContentType.TextPlain:
 607       default:
 608         return [err.errorMessage, err.details].join('\r\n');
 609     }
 610   }
 611
 612
 613   /**
 614    * Send an error response.  Terminal.
 615    * Logs any non-error-response errors as such.
 616    * @param {object} err either an Error object, or an error response
 617    * @param {http.ClientRequest} req
 618    * @param {http.ServerResponse} res
 619    * @param {object} ctx
 620    */
 621   sendErrorResponse(err, req, res, ctx) {
 622     const _scope = _fileScope('sendErrorResponse');
 623     let body;
 624
 625     // Default to a content type if one is not yet present
 626     if (!res.hasHeader(Enum.Header.ContentType)) {
 627       res.setHeader(Enum.Header.ContentType, Enum.ContentType.TextPlain);
 628     }
 629
 630     if (err && err.statusCode) {
 631       res.statusCode = err.statusCode;
 632       body = this.renderError(res.getHeader(Enum.Header.ContentType), err);
 633       this.logger.debug(_scope, 'handler error', { err, ...common.handlerLogData(req, res, ctx) });
 634     } else {
 635       res.statusCode = 500;
 636       body = this.renderError(res.getHeader(Enum.Header.ContentType), Enum.ErrorResponse.InternalServerError);
 637       this.logger.error(_scope, 'handler exception', { err, ...common.handlerLogData(req, res, ctx) });
 638     }
 639     res.end(body);
 640   }
 641
 642
 643   /**
 644    * @param {http.ClientRequest} req
 645    * @param {http.ServerResponse} res
 646    * @param {object} ctx
 647    * @param {String} file - override ctx.params.file
 648    */
 649   async handlerGetStaticFile(req, res, ctx, file) {
 650     Dingus.setHeadHandler(req, res, ctx);
 651
 652     // Set a default response type to handle any errors; will be re-set to serve actual static content type.
 653     this.setResponseType(this.responseTypes, req, res, ctx);
 654
 655     await this.serveFile(req, res, ctx, this.staticPath, file || ctx.params.file);
 656   }
 657
 658
 659   /**
 660    * @param {http.ClientRequest} req
 661    * @param {http.ServerResponse} res
 662    * @param {Object} ctx
 663    * @param {String} newPath
 664    * @param {Number} statusCode
 665   */
 666   async handlerRedirect(req, res, ctx, newPath, statusCode = 307) {
 667     this.setResponseType(this.responseTypes, req, res, ctx);
 668     res.setHeader(Enum.Header.Location, newPath);
 669     res.statusCode = statusCode;
 670     res.end();
 671   }
 672
 673
 674   /**
 675    * @param {http.ClientRequest} req
 676    * @param {http.ServerResponse} res
 677    * @param {object} ctx
 678    */
 679   async handlerMethodNotAllowed(req, res, ctx) {
 680     this.setResponseType(this.responseTypes, req, res, ctx);
 681     throw new ResponseError(Enum.ErrorResponse.MethodNotAllowed);
 682   }
 683
 684
 685   /**
 686    * @param {http.ClientRequest} req
 687    * @param {http.ServerResponse} res
 688    * @param {object} ctx
 689    */
 690   async handlerNotFound(req, res, ctx) {
 691     this.setResponseType(this.responseTypes, req, res, ctx);
 692     throw new ResponseError(Enum.ErrorResponse.NotFound);
 693   }
 694
 695
 696   /**
 697    * @param {http.ClientRequest} req
 698    * @param {http.ServerResponse} res
 699    * @param {object} ctx
 700    */
 701   async handlerBadRequest(req, res, ctx) {
 702     this.setResponseType(this.responseTypes, req, res, ctx);
 703     throw new ResponseError(Enum.ErrorResponse.BadRequest);
 704   }
 705
 706
 707   /**
 708    * @param {http.ClientRequest} req
 709    * @param {http.ServerResponse} res
 710    * @param {object} ctx
 711    */
 712   async handlerInternalServerError(req, res, ctx) {
 713     this.setResponseType(this.responseTypes, req, res, ctx);
 714     throw new ResponseError(Enum.ErrorResponse.InternalServerError);
 715   }
 716
 717 }
 718
 719 module.exports = Dingus;