chore: remove "version" property from "svrjs.core.json" and create SVR.JS Core documentation

.gitignore

@@ -1,6 +1,7 @@
 # Build output
 /dist/
 /out/
+/core/
 
 # Temporary files used by build script
 /generatedAssets/

README.md

@@ -81,7 +81,7 @@ After installing the packages, build SVR.JS with this command:
 ```bash
 npm run build 
 ```
-After running the command, you will get bundled SVR.JS script, around with built-in utilities and assets in the `dist` directory. You will also get a zip archive in `out` directory, that can be installed using SVR.JS installer
+After running the command, you will get bundled SVR.JS script, around with built-in utilities and assets in the `dist` directory. You will also get a zip archive in `out` directory, that can be installed using SVR.JS installer. Additionally, you will get the SVR.JS Core package contents in the `core` directory, which you can publish by running `npm publish` in the `core` directory.
 
 ## Installation (built from source)
 
@@ -118,6 +118,8 @@ You can read the [SVR.JS documentation](https://svrjs.org/docs) to get informati
 The file structure for SVR.JS source code looks like this:
  - .husky - Git hooks
  - assets - files to copy into dist folder and to the archive
+ - core - contains SVR.JS Core
+ - coreAssets - files to copy into core folder
  - dist - contains SVR.JS, assets, and SVR.JS utiltiies
  - generatedAssets - assets generated by the build script
  - out - contains SVR.JS zip archive

coreAssets/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018-2024 SVR.JS
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coreAssets/README.md

@@ -0,0 +1,64 @@
+# SVR.JS Core
+
+SVR.JS Core is a library for static file serving, built from SVR.JS source code.
+
+Example code (with Node.JS "http" module):
+```javascript
+var http = require("http");
+var fs = require("fs");
+var url = require("url");
+var svrjsCore = require("svrjs-core").init(); // Initialize SVR.JS Core
+var server = http.createServer(function (req,res) {
+  if(url.parse(req.url).pathname == "/useragent") {
+	  res.writeHead(200, "OK", {"content-type": "text-plain"}); // Output as plain text
+	  res.end("Your user agent: " + req.headers["user-agent"]); // Send user agent
+  } else {
+      svrjsCore(req,res); // Serve static content
+  }
+}).listen(8888);
+```
+
+Example code (with Express):
+```javascript
+var express = require("express");
+var svrjsCore = require("svrjs-core");
+
+var app = express();
+app.use(svrjsCore());
+
+app.listen(3000);
+```
+
+## Methods
+
+### *svrjsCore([config])*
+
+Parameters:
+
+- *config* - the SVR.JS Core configuration (optional, *Object*)
+
+Returns: the request handler for use in Node.JS HTTP server or Express, with three parameters (*req*, *res*, and optional *next*)
+
+The *config* object is almost the same format as SVR.JS configuration. You can read about SVR.JS configuration properties in [the SVR.JS documentation](https://svrjs.org/docs/config/configuration).
+
+However, only these SVR.JS configuration properties apply to SVR.JS Core:
+- *users*
+- *page404*
+- *enableCompression*
+- *customHeaders*
+- *enableDirectoryListing*
+- *enableDirectoryListingWithDefaultHead*
+- *serverAdministratorEmail*
+- *stackHidden*
+- *exposeServerVersion*
+- *dontCompress*
+- *enableIPSpoofing*
+- *enableETag*
+- *rewriteDirtyURLs*
+- *errorPages*
+- *disableTrailingSlashRedirects*
+- *allowDoubleSlashes*
+
+### *svrjsCore.init([config])*
+
+An alias to the *svrjsCore()* function

esbuild.config.js

@@ -7,6 +7,11 @@ const archiver = require("archiver");
 const chokidar = require("chokidar");
 const svrjsInfo = JSON.parse(fs.readFileSync(__dirname + "/svrjs.json"));
 const { version } = svrjsInfo;
+const svrjsCoreInfo = JSON.parse(
+  fs.readFileSync(__dirname + "/svrjs.core.json")
+);
+const { externalPackages } = svrjsCoreInfo;
+const corePackageJSON = svrjsCoreInfo.packageJSON;
 const isDev = process.env.NODE_ENV == "development";
 
 // Create the dist directory if it doesn't exist
@@ -19,7 +24,12 @@ if (!fs.existsSync(__dirname + "/dist/temp"))
   fs.mkdirSync(__dirname + "/dist/temp");
 
 // Create the out directory if it doesn't exist and if not building for development
-if (!isDev && !fs.existsSync(__dirname + "/out")) fs.mkdirSync(__dirname + "/out");
+if (!isDev && !fs.existsSync(__dirname + "/out"))
+  fs.mkdirSync(__dirname + "/out");
+
+// Create the core directory if it doesn't exist and if not building for development
+if (!isDev && !fs.existsSync(__dirname + "/core"))
+  fs.mkdirSync(__dirname + "/core");
 
 function generateAssets() {
   // Variables from "svrjs.json" file
@@ -171,23 +181,25 @@ if (!isDev) {
     __dirname + "/package.json",
     __dirname + "/svrjs.json"
   ]);
-  watcher.on("change", () => {
-    try {
-      generateAssets();
-    } catch (err) {
-      console.error("There is a problem when regenerating assets!");
-      console.error("Stack:");
-      console.error(err.stack);
-    }
-  }).on("ready", () => {
-    try {
-      generateAssets();
-    } catch (err) {
-      console.error("There is a problem when regenerating assets!");
-      console.error("Stack:");
-      console.error(err.stack);
-    }
-  });
+  watcher
+    .on("change", () => {
+      try {
+        generateAssets();
+      } catch (err) {
+        console.error("There is a problem when regenerating assets!");
+        console.error("Stack:");
+        console.error(err.stack);
+      }
+    })
+    .on("ready", () => {
+      try {
+        generateAssets();
+      } catch (err) {
+        console.error("There is a problem when regenerating assets!");
+        console.error("Stack:");
+        console.error(err.stack);
+      }
+    });
 }
 
 if (!isDev) {
@@ -243,39 +255,93 @@ if (!isDev) {
           target: "es2017"
         })
         .then(() => {
-          const archiveName =
-            "svr.js." +
-            version.toLowerCase().replace(/[^0-9a-z]+/g, ".") +
-            ".zip";
-          const output = fs.createWriteStream(
-            __dirname + "/out/" + archiveName
+          const dependencies =
+            JSON.parse(fs.readFileSync(__dirname + "/package.json"))
+              .dependencies || {};
+          const coreDependencyNames = Object.keys(dependencies).filter(
+            (dependency) => externalPackages.indexOf(dependency) != -1
           );
-          const archive = archiver("zip", {
-            zlib: { level: 9 }
-          });
-          archive.pipe(output);
+          const packageJSON = Object.assign({}, corePackageJSON);
 
-          // Add everything in the "dist" directory except for "svr.js" and "svr.compressed"
-          archive.glob("**/*", {
-            cwd: __dirname + "/dist",
-            ignore: ["svr.js", "svr.compressed"],
-            dot: true
-          });
-
-          // Create a stream for the "svr.compressed" file
-          const compressedSVRJSFileStream = fs
-            .createReadStream(__dirname + "/dist/svr.js")
-            .pipe(
-              zlib.createGzip({
-                level: 9
-              })
-            );
-          archive.append(compressedSVRJSFileStream, { name: "svr.compressed" });
-          archive.append(
-            'const zlib = require("zlib");\nconst fs = require("fs");\nconsole.log("Deleting SVR.JS stub...");\nfs.unlinkSync("svr.js");\nconsole.log("Decompressing SVR.JS...");\nconst script = zlib.gunzipSync(fs.readFileSync("svr.compressed"));\nfs.unlinkSync("svr.compressed");\nfs.writeFileSync("svr.js",script);\nconsole.log("Restart SVR.JS to get server interface.");',
-            { name: "svr.js" }
+          // Add package.json properties
+          packageJSON.version = version;
+          packageJSON.main = "./svr.core.js";
+          packageJSON.dependencies = coreDependencyNames.reduce(
+            (previousDependencies, dependency) => {
+              previousDependencies[dependency] = dependencies[dependency];
+              return previousDependencies;
+            },
+            {}
           );
-          archive.finalize();
+
+          // Write package.json
+          fs.writeFileSync(
+            __dirname + "/core/package.json",
+            JSON.stringify(packageJSON, null, 2)
+          );
+
+          // Build SVR.JS Core
+          esbuild
+            .build({
+              entryPoints: ["src/core.js"],
+              bundle: true,
+              outfile: "core/svr.core.js",
+              platform: "node",
+              target: "es2017",
+              external: coreDependencyNames,
+              plugins: [
+                esbuildCopyPlugin.copy({
+                  resolveFrom: __dirname,
+                  assets: {
+                    from: ["./coreAssets/**/*"],
+                    to: ["./core"]
+                  },
+                  globbyOptions: {
+                    dot: true
+                  }
+                })
+              ]
+            })
+            .then(() => {
+              const archiveName =
+                "svr.js." +
+                version.toLowerCase().replace(/[^0-9a-z]+/g, ".") +
+                ".zip";
+              const output = fs.createWriteStream(
+                __dirname + "/out/" + archiveName
+              );
+              const archive = archiver("zip", {
+                zlib: { level: 9 }
+              });
+              archive.pipe(output);
+
+              // Add everything in the "dist" directory except for "svr.js" and "svr.compressed"
+              archive.glob("**/*", {
+                cwd: __dirname + "/dist",
+                ignore: ["svr.js", "svr.compressed"],
+                dot: true
+              });
+
+              // Create a stream for the "svr.compressed" file
+              const compressedSVRJSFileStream = fs
+                .createReadStream(__dirname + "/dist/svr.js")
+                .pipe(
+                  zlib.createGzip({
+                    level: 9
+                  })
+                );
+              archive.append(compressedSVRJSFileStream, {
+                name: "svr.compressed"
+              });
+              archive.append(
+                'const zlib = require("zlib");\nconst fs = require("fs");\nconsole.log("Deleting SVR.JS stub...");\nfs.unlinkSync("svr.js");\nconsole.log("Decompressing SVR.JS...");\nconst script = zlib.gunzipSync(fs.readFileSync("svr.compressed"));\nfs.unlinkSync("svr.compressed");\nfs.writeFileSync("svr.js",script);\nconsole.log("Restart SVR.JS to get server interface.");',
+                { name: "svr.js" }
+              );
+              archive.finalize();
+            })
+            .catch((err) => {
+              throw err;
+            });
         })
         .catch((err) => {
           throw err;

package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "build": "npm run clean && NODE_ENV=production node esbuild.config.js",
     "cz": "cz",
-    "clean": "rimraf dist && rimraf out && rimraf generatedAssets",
+    "clean": "rimraf dist && rimraf out && rimraf generatedAssets && rimraf core",
     "dev": "npm run clean && concurrently \"NODE_ENV=development node esbuild.config.js\" \"wait-on dist/svr.js && nodemon dist/svr.js --stdout-notty --no-save-config\"",
     "lint": "eslint --no-error-on-unmatched-pattern src/**/*.js src/*.js tests/**/*.test.js tests/**/*.js tests/*.test.js tests/*.js",
     "lint:fix": "npm run lint -- --fix",

src/core.js

@@ -0,0 +1,672 @@
+const fs = require("fs");
+const net = require("net");
+const defaultPageCSS = require("./res/defaultPageCSS.js");
+const generateErrorStack = require("./utils/generateErrorStack.js");
+const serverHTTPErrorDescs = require("./res/httpErrorDescriptions.js");
+const fixNodeMojibakeURL = require("./utils/urlMojibakeFixer.js");
+const ipMatch = require("./utils/ipMatch.js");
+const matchHostname = require("./utils/matchHostname.js");
+const generateServerStringCore = require("./utils/generateServerStringCore.js");
+const parseURL = require("./utils/urlParser.js");
+const deepClone = require("./utils/deepClone.js");
+const statusCodes = require("./res/statusCodes.js");
+
+const middleware = [
+  require("./middleware/urlSanitizer.js"),
+  require("./middleware/redirectTrailingSlashes.js"),
+  require("./middleware/defaultHandlerChecks.js"),
+  require("./middleware/staticFileServingAndDirectoryListings.js")
+];
+let coreConfig = {};
+
+function requestHandler(req, res, next) {
+  // SVR.JS log facilities (stubs in SVR.JS core)
+  const logFacilities = {
+    climessage: () => {},
+    reqmessage: () => {},
+    resmessage: () => {},
+    errmessage: () => {},
+    locerrmessage: () => {},
+    locwarnmessage: () => {},
+    locmessage: () => {}
+  };
+
+  // SVR.JS configuration object (modified)
+  const config = deepClone(coreConfig);
+
+  config.generateServerString = () =>
+    generateServerStringCore(config.exposeServerVersion);
+
+  // Determine the webroot from the current working directory if it is not configured
+  if (config.wwwroot === undefined) config.wwwroot = process.cwd();
+
+  // getCustomHeaders() in SVR.JS 3.x
+  config.getCustomHeaders = () => {
+    let ph = Object.assign({}, config.customHeaders);
+    if (config.customHeadersVHost) {
+      let vhostP = null;
+      config.customHeadersVHost.every((vhost) => {
+        if (
+          matchHostname(vhost.host, req.headers.host) &&
+          ipMatch(vhost.ip, req.socket ? req.socket.localAddress : undefined)
+        ) {
+          vhostP = vhost;
+          return false;
+        } else {
+          return true;
+        }
+      });
+      if (vhostP && vhostP.headers) ph = { ...ph, ...vhostP.headers };
+    }
+    Object.keys(ph).forEach((phk) => {
+      if (typeof ph[phk] == "string")
+        ph[phk] = ph[phk].replace(/\{path\}/g, req.url);
+    });
+    return ph;
+  };
+
+  // Make HTTP/1.x API-based scripts compatible with HTTP/2.0 API
+  if (config.enableHTTP2 == true && req.httpVersion == "2.0") {
+    // Set HTTP/1.x methods (to prevent process warnings)
+    res.writeHeadNodeApi = res.writeHead;
+    res.setHeaderNodeApi = res.setHeader;
+
+    res.writeHead = (a, b, c) => {
+      let table = c;
+      if (typeof b == "object") table = b;
+      if (table == undefined) table = this.tHeaders;
+      if (table == undefined) table = {};
+      table = Object.assign({}, table);
+      Object.keys(table).forEach((key) => {
+        const al = key.toLowerCase();
+        if (
+          al == "transfer-encoding" ||
+          al == "connection" ||
+          al == "keep-alive" ||
+          al == "upgrade"
+        )
+          delete table[key];
+      });
+      if (res.stream && res.stream.destroyed) {
+        return false;
+      } else {
+        return res.writeHeadNodeApi(a, table);
+      }
+    };
+    res.setHeader = (headerName, headerValue) => {
+      const al = headerName.toLowerCase();
+      if (
+        al != "transfer-encoding" &&
+        al != "connection" &&
+        al != "keep-alive" &&
+        al != "upgrade"
+      )
+        return res.setHeaderNodeApi(headerName, headerValue);
+      return false;
+    };
+
+    // Set HTTP/1.x headers
+    if (!req.headers.host) req.headers.host = req.headers[":authority"];
+    if (!req.url) req.url = req.headers[":path"];
+    if (!req.protocol) req.protocol = req.headers[":scheme"];
+    if (!req.method) req.method = req.headers[":method"];
+    if (
+      req.headers[":path"] == undefined ||
+      req.headers[":method"] == undefined
+    ) {
+      let err = new Error(
+        'Either ":path" or ":method" pseudoheader is missing.'
+      );
+      if (Buffer.alloc) err.rawPacket = Buffer.alloc(0);
+      if (req.socket && req.socket.server)
+        req.socket.server.emit("clientError", err, req.socket);
+    }
+  }
+
+  req.url = fixNodeMojibakeURL(req.url);
+
+  req.isProxy = false;
+
+  if (req.socket == null) return;
+
+  // Set up X-Forwarded-For
+  let reqip = req.socket.remoteAddress;
+  let reqport = req.socket.remotePort;
+  let oldip = "";
+  let oldport = "";
+  let isForwardedValid = true;
+  if (config.enableIPSpoofing) {
+    if (req.headers["x-forwarded-for"] != undefined) {
+      let preparedReqIP = req.headers["x-forwarded-for"]
+        .split(",")[0]
+        .replace(/ /g, "");
+      let preparedReqIPvalid = net.isIP(preparedReqIP);
+      if (preparedReqIPvalid) {
+        if (
+          preparedReqIPvalid == 4 &&
+          req.socket.remoteAddress &&
+          req.socket.remoteAddress.indexOf(":") > -1
+        )
+          preparedReqIP = "::ffff:" + preparedReqIP;
+        reqip = preparedReqIP;
+        reqport = null;
+        try {
+          oldport = req.socket.remotePort;
+          oldip = req.socket.remoteAddress;
+          req.socket.realRemotePort = reqport;
+          req.socket.realRemoteAddress = reqip;
+          req.socket.originalRemotePort = oldport;
+          req.socket.originalRemoteAddress = oldip;
+          res.socket.realRemotePort = reqport;
+          res.socket.realRemoteAddress = reqip;
+          res.socket.originalRemotePort = oldport;
+          res.socket.originalRemoteAddress = oldip;
+          // eslint-disable-next-line no-unused-vars
+        } catch (err) {
+          // Address setting failed
+        }
+      } else {
+        isForwardedValid = false;
+      }
+    }
+  }
+
+  // Process the Host header
+  if (typeof req.headers.host == "string") {
+    req.headers.host = req.headers.host.toLowerCase();
+    if (!req.headers.host.match(/^\.+$/))
+      req.headers.host = req.headers.host.replace(/\.$/, "");
+  }
+
+  // Header and footer placeholders
+  res.head = "";
+  res.foot = "";
+
+  res.responseEnd = (body) => {
+    // If body is Buffer, then it is converted to String anyway.
+    res.write(res.head + body + res.foot);
+    res.end();
+  };
+
+  const defaultServerError = (errorCode, extName, stack, ch) => {
+    // Determine error file
+    const getErrorFileName = (list, callback, _i) => {
+      const medCallback = (p) => {
+        if (p) callback(p);
+        else {
+          if (errorCode == 404) {
+            fs.access(config.page404, fs.constants.F_OK, (err) => {
+              if (err) {
+                fs.access(
+                  config.wwwroot + "/." + errorCode.toString(),
+                  fs.constants.F_OK,
+                  (err) => {
+                    try {
+                      if (err) {
+                        callback(errorCode.toString() + ".html");
+                      } else {
+                        callback(config.wwwroot + "/." + errorCode.toString());
+                      }
+                    } catch (err2) {
+                      res.error(500, err2);
+                    }
+                  }
+                );
+              } else {
+                try {
+                  callback(config.page404);
+                } catch (err2) {
+                  res.error(500, err2);
+                }
+              }
+            });
+          } else {
+            fs.access(
+              config.wwwroot + "/." + errorCode.toString(),
+              fs.constants.F_OK,
+              (err) => {
+                try {
+                  if (err) {
+                    callback(errorCode.toString() + ".html");
+                  } else {
+                    callback(config.wwwroot + "/." + errorCode.toString());
+                  }
+                } catch (err2) {
+                  res.error(500, err2);
+                }
+              }
+            );
+          }
+        }
+      };
+
+      if (!_i) _i = 0;
+      if (_i >= list.length) {
+        medCallback(false);
+        return;
+      }
+
+      if (
+        list[_i].scode != errorCode ||
+        !(
+          matchHostname(list[_i].host, req.headers.host) &&
+          ipMatch(list[_i].ip, req.socket ? req.socket.localAddress : undefined)
+        )
+      ) {
+        getErrorFileName(list, callback, _i + 1);
+        return;
+      } else {
+        fs.access(list[_i].path, fs.constants.F_OK, (err) => {
+          if (err) {
+            getErrorFileName(list, callback, _i + 1);
+          } else {
+            medCallback(list[_i].path);
+          }
+        });
+      }
+    };
+
+    getErrorFileName(config.errorPages, (errorFile) => {
+      // Generate error stack if not provided
+      if (Object.prototype.toString.call(stack) === "[object Error]")
+        stack = generateErrorStack(stack);
+      if (stack === undefined)
+        stack = generateErrorStack(new Error("Unknown error"));
+
+      // Hide the error stack if specified
+      if (config.stackHidden) stack = "[error stack hidden]";
+
+      // Validate the error code and handle unknown codes
+      if (serverHTTPErrorDescs[errorCode] === undefined) {
+        res.error(501, extName, stack);
+      } else {
+        // Process custom headers if provided
+        let cheaders = { ...config.getCustomHeaders(), ...ch };
+
+        cheaders["Content-Type"] = "text/html; charset=utf-8";
+
+        // Set default Allow header for 405 error if not provided
+        if (errorCode == 405 && !cheaders["Allow"])
+          cheaders["Allow"] = "GET, POST, HEAD, OPTIONS";
+
+        // Read the error file and replace placeholders with error information
+        fs.readFile(errorFile, (err, data) => {
+          try {
+            if (err) throw err;
+            res.writeHead(errorCode, statusCodes[errorCode], cheaders);
+            res.responseEnd(
+              data
+                .toString()
+                .replace(
+                  /{errorMessage}/g,
+                  errorCode.toString() +
+                    " " +
+                    statusCodes[errorCode]
+                      .replace(/&/g, "&")
+                      .replace(/</g, "&lt;")
+                      .replace(/>/g, "&gt;")
+                )
+                .replace(/{errorDesc}/g, serverHTTPErrorDescs[errorCode])
+                .replace(
+                  /{stack}/g,
+                  stack
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                    .replace(/\r\n/g, "<br/>")
+                    .replace(/\n/g, "<br/>")
+                    .replace(/\r/g, "<br/>")
+                    .replace(/ {2}/g, "&nbsp;&nbsp;")
+                )
+                .replace(
+                  /{path}/g,
+                  req.url
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                )
+                .replace(
+                  /{server}/g,
+                  "" +
+                    (
+                      config.generateServerString() +
+                      (!config.exposeModsInErrorPages || extName == undefined
+                        ? ""
+                        : " " + extName)
+                    )
+                      .replace(/&/g, "&amp;")
+                      .replace(/</g, "&lt;")
+                      .replace(/>/g, "&gt;") +
+                    (req.headers.host == undefined || req.isProxy
+                      ? ""
+                      : " on " +
+                        String(req.headers.host)
+                          .replace(/&/g, "&amp;")
+                          .replace(/</g, "&lt;")
+                          .replace(/>/g, "&gt;"))
+                )
+                .replace(
+                  /{contact}/g,
+                  config.serverAdministratorEmail
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                    .replace(/\./g, "[dot]")
+                    .replace(/@/g, "[at]")
+                )
+            ); // Replace placeholders in error response
+          } catch (err) {
+            let additionalError = 500;
+            // Handle additional error cases
+            if (err.code == "ENOENT") {
+              additionalError = 404;
+            } else if (err.code == "ENOTDIR") {
+              additionalError = 404; // Assume that file doesn't exist
+            } else if (err.code == "EACCES") {
+              additionalError = 403;
+            } else if (err.code == "ENAMETOOLONG") {
+              additionalError = 414;
+            } else if (err.code == "EMFILE") {
+              additionalError = 503;
+            } else if (err.code == "ELOOP") {
+              additionalError = 508;
+            }
+
+            res.writeHead(errorCode, statusCodes[errorCode], cheaders);
+            res.write(
+              `<!DOCTYPE html><html><head><title>{errorMessage}</title><meta name="viewport" content="width=device-width, initial-scale=1.0" /><style>${defaultPageCSS}</style></head><body><h1>{errorMessage}</h1><p>{errorDesc}</p>${
+                additionalError == 404
+                  ? ""
+                  : "<p>Additionally, a {additionalError} error occurred while loading an error page.</p>"
+              }<p><i>{server}</i></p></body></html>`
+                .replace(
+                  /{errorMessage}/g,
+                  errorCode.toString() +
+                    " " +
+                    statusCodes[errorCode]
+                      .replace(/&/g, "&amp;")
+                      .replace(/</g, "&lt;")
+                      .replace(/>/g, "&gt;")
+                )
+                .replace(/{errorDesc}/g, serverHTTPErrorDescs[errorCode])
+                .replace(
+                  /{stack}/g,
+                  stack
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                    .replace(/\r\n/g, "<br/>")
+                    .replace(/\n/g, "<br/>")
+                    .replace(/\r/g, "<br/>")
+                    .replace(/ {2}/g, "&nbsp;&nbsp;")
+                )
+                .replace(
+                  /{path}/g,
+                  req.url
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                )
+                .replace(
+                  /{server}/g,
+                  "" +
+                    (
+                      config.generateServerString() +
+                      (!config.exposeModsInErrorPages || extName == undefined
+                        ? ""
+                        : " " + extName)
+                    )
+                      .replace(/&/g, "&amp;")
+                      .replace(/</g, "&lt;")
+                      .replace(/>/g, "&gt;") +
+                    (req.headers.host == undefined || req.isProxy
+                      ? ""
+                      : " on " +
+                        String(req.headers.host)
+                          .replace(/&/g, "&amp;")
+                          .replace(/</g, "&lt;")
+                          .replace(/>/g, "&gt;"))
+                )
+                .replace(
+                  /{contact}/g,
+                  config.serverAdministratorEmail
+                    .replace(/&/g, "&amp;")
+                    .replace(/</g, "&lt;")
+                    .replace(/>/g, "&gt;")
+                    .replace(/\./g, "[dot]")
+                    .replace(/@/g, "[at]")
+                )
+                .replace(/{additionalError}/g, additionalError.toString())
+            ); // Replace placeholders in error response
+            res.end();
+          }
+        });
+      }
+    });
+  };
+
+  // Server error calling method
+  res.error = (errorCode, extName, stack, ch) => {
+    if (typeof errorCode !== "number") {
+      throw new TypeError("HTTP error code parameter needs to be an integer.");
+    }
+
+    // Handle optional parameters
+    if (extName && typeof extName === "object") {
+      ch = stack;
+      stack = extName;
+      extName = undefined;
+    } else if (
+      typeof extName !== "string" &&
+      extName !== null &&
+      extName !== undefined
+    ) {
+      throw new TypeError("Extension name parameter needs to be a string.");
+    }
+
+    if (
+      stack &&
+      typeof stack === "object" &&
+      Object.prototype.toString.call(stack) !== "[object Error]"
+    ) {
+      ch = stack;
+      stack = undefined;
+    } else if (
+      typeof stack !== "object" &&
+      typeof stack !== "string" &&
+      stack
+    ) {
+      throw new TypeError(
+        "Error stack parameter needs to be either a string or an instance of Error object."
+      );
+    }
+
+    if (next) {
+      // Invoke next() handler, like when it is used in Express
+      if (errorCode == 500) {
+        next(new Error("Internal SVR.JS core error"));
+      } else {
+        next();
+      }
+    } else {
+      // Invoke default server error handler
+      defaultServerError(errorCode, extName, stack, ch);
+    }
+  };
+
+  // Function to perform HTTP redirection to a specified destination URL
+  res.redirect = (destination, isTemporary, keepMethod, customHeaders) => {
+    // If keepMethod is a object, then save it to customHeaders
+    if (typeof keepMethod == "object") customHeaders = keepMethod;
+
+    // If isTemporary is a object, then save it to customHeaders
+    if (typeof isTemporary == "object") customHeaders = isTemporary;
+
+    // If customHeaders are not provided, get the default custom headers
+    if (customHeaders === undefined) customHeaders = config.getCustomHeaders();
+
+    // Set the "Location" header to the destination URL
+    customHeaders["Location"] = destination;
+
+    // Determine the status code for redirection based on the isTemporary and keepMethod flags
+    const statusCode = keepMethod
+      ? isTemporary
+        ? 307
+        : 308
+      : isTemporary
+        ? 302
+        : 301;
+
+    // Write the response header with the appropriate status code and message
+    res.writeHead(statusCode, statusCodes[statusCode], customHeaders);
+
+    // End the response
+    res.end();
+
+    // Return from the function
+    return;
+  };
+
+  try {
+    res.head = fs.existsSync(`${config.wwwroot}/.head`)
+      ? fs.readFileSync(`${config.wwwroot}/.head`).toString()
+      : fs.existsSync(`${config.wwwroot}/head.html`)
+        ? fs.readFileSync(`${config.wwwroot}/head.html`).toString()
+        : ""; // header
+    res.foot = fs.existsSync(`${config.wwwroot}/.foot`)
+      ? fs.readFileSync(`${config.wwwroot}/.foot`).toString()
+      : fs.existsSync(`${config.wwwroot}/foot.html`)
+        ? fs.readFileSync(`${config.wwwroot}/foot.html`).toString()
+        : ""; // footer
+  } catch (err) {
+    res.error(500, err);
+  }
+
+  // Authenticated user variable
+  req.authUser = null;
+
+  if (req.url == "*") {
+    // Handle "*" URL
+    if (req.method == "OPTIONS") {
+      // Respond with list of methods
+      let hdss = config.getCustomHeaders();
+      hdss["Allow"] = "GET, POST, HEAD, OPTIONS";
+      res.writeHead(204, statusCodes[204], hdss);
+      res.end();
+      return;
+    } else {
+      // SVR.JS doesn't understand that request, so throw an 400 error
+      res.error(400);
+      return;
+    }
+  }
+
+  if (req.headers["expect"] && req.headers["expect"] != "100-continue") {
+    // Expectations not met.
+    res.error(417);
+    return;
+  }
+
+  if (req.method == "CONNECT") {
+    // CONNECT requests should be handled in "connect" event.
+    res.error(501);
+    return;
+  }
+
+  if (!isForwardedValid) {
+    res.error(400);
+    return;
+  }
+
+  try {
+    req.parsedURL = parseURL(
+      req.url,
+      "http" +
+        (req.socket.encrypted ? "s" : "") +
+        "://" +
+        (req.headers.host
+          ? req.headers.host
+          : config.domain
+            ? config.domain
+            : "unknown.invalid")
+    );
+
+    // req.originalParsedURL fallback
+    req.originalParsedURL = req.parsedURL;
+  } catch (err) {
+    res.error(400, err);
+    return;
+  }
+
+  let index = 0;
+
+  // Call the next middleware function
+  const nextMiddleware = () => {
+    let currentMiddleware = middleware[index++];
+    while (
+      req.isProxy &&
+      currentMiddleware &&
+      currentMiddleware.proxySafe !== false &&
+      !(currentMiddleware.proxySafe || currentMiddleware.proxy)
+    ) {
+      currentMiddleware = middleware[index++];
+    }
+    if (currentMiddleware) {
+      try {
+        currentMiddleware(req, res, logFacilities, config, nextMiddleware);
+      } catch (err) {
+        res.error(500, err);
+      }
+    } else {
+      res.error(404);
+    }
+  };
+
+  // Handle middleware
+  nextMiddleware();
+}
+
+function init(config) {
+  if (config) coreConfig = config;
+
+  if (coreConfig.users === undefined) coreConfig.users = [];
+  if (coreConfig.page404 === undefined) coreConfig.page404 = "404.html";
+  if (coreConfig.enableCompression === undefined)
+    coreConfig.enableCompression = true;
+  if (coreConfig.customHeaders === undefined) coreConfig.customHeaders = {};
+  if (coreConfig.enableDirectoryListing === undefined)
+    coreConfig.enableDirectoryListing = true;
+  if (coreConfig.enableDirectoryListingWithDefaultHead === undefined)
+    coreConfig.enableDirectoryListingWithDefaultHead = false;
+  if (coreConfig.serverAdministratorEmail === undefined)
+    coreConfig.serverAdministratorEmail = "[no contact information]";
+  if (coreConfig.stackHidden === undefined) coreConfig.stackHidden = false;
+  if (coreConfig.exposeServerVersion === undefined)
+    coreConfig.exposeServerVersion = true;
+  if (coreConfig.dontCompress === undefined)
+    coreConfig.dontCompress = [
+      "/.*\\.ipxe$/",
+      "/.*\\.(?:jpe?g|png|bmp|tiff|jfif|gif|webp)$/",
+      "/.*\\.(?:[id]mg|iso|flp)$/",
+      "/.*\\.(?:zip|rar|bz2|[gb7x]z|lzma|tar)$/",
+      "/.*\\.(?:mp[34]|mov|wm[av]|avi|webm|og[gv]|mk[va])$/"
+    ];
+  if (coreConfig.enableIPSpoofing === undefined)
+    coreConfig.enableIPSpoofing = false;
+  if (coreConfig.enableETag === undefined) coreConfig.enableETag = true;
+  if (coreConfig.rewriteDirtyURLs === undefined)
+    coreConfig.rewriteDirtyURLs = false;
+  if (coreConfig.errorPages === undefined) coreConfig.errorPages = [];
+  if (coreConfig.disableTrailingSlashRedirects === undefined)
+    coreConfig.disableTrailingSlashRedirects = false;
+  if (coreConfig.allowDoubleSlashes === undefined)
+    coreConfig.allowDoubleSlashes = false;
+
+  // You wouldn't use SVR.JS mods in SVR.JS Core
+  coreConfig.exposeModsInErrorPages = false;
+
+  return requestHandler;
+}
+
+module.exports = init;
+module.exports.init = init;

src/handlers/requestHandler.js

@@ -706,6 +706,9 @@ function requestHandler(req, res) {
             ? config.domain
             : "unknown.invalid")
     );
+
+    // req.originalParsedURL fallback
+    req.originalParsedURL = req.parsedURL;
   } catch (err) {
     res.error(400, err);
     return;
@@ -714,7 +717,7 @@ function requestHandler(req, res) {
   let index = 0;
 
   // Call the next middleware function
-  const next = () => {
+  const nextMiddleware = () => {
     let currentMiddleware = middleware[index++];
     while (
       req.isProxy &&
@@ -726,7 +729,7 @@ function requestHandler(req, res) {
     }
     if (currentMiddleware) {
       try {
-        currentMiddleware(req, res, logFacilities, config, next);
+        currentMiddleware(req, res, logFacilities, config, nextMiddleware);
       } catch (err) {
         res.error(500, err);
       }
@@ -736,7 +739,7 @@ function requestHandler(req, res) {
   };
 
   // Handle middleware
-  next();
+  nextMiddleware();
 }
 
 module.exports = (serverconsoleO, middlewareO) => {

src/index.js

@@ -854,7 +854,7 @@ if (!disableMods) {
 }
 
 // Middleware
-let middleware = [
+const middleware = [
   require("./middleware/urlSanitizer.js"),
   require("./middleware/redirects.js"),
   require("./middleware/blocklist.js"),

src/middleware/staticFileServingAndDirectoryListings.js

@@ -980,7 +980,32 @@ module.exports = (req, res, logFacilities, config, next) => {
     } else if (dirImagesMissing) {
       fs.stat(readFrom, (e, s) => {
         if (e || !s.isFile()) {
-          properDirectoryListingAndStaticFileServe();
+          if (err.code == "ENOENT") {
+            res.error(404);
+            logFacilities.errmessage("Resource not found.");
+            return;
+          } else if (err.code == "ENOTDIR") {
+            res.error(404); // Assume that file doesn't exist.
+            logFacilities.errmessage("Resource not found.");
+            return;
+          } else if (err.code == "EACCES") {
+            res.error(403);
+            logFacilities.errmessage("Access denied.");
+            return;
+          } else if (err.code == "ENAMETOOLONG") {
+            res.error(414);
+            return;
+          } else if (err.code == "EMFILE") {
+            res.error(503);
+            return;
+          } else if (err.code == "ELOOP") {
+            res.error(508); // The symbolic link loop is detected during file system operations.
+            logFacilities.errmessage("Symbolic link loop detected.");
+            return;
+          } else {
+            res.error(500, err);
+            return;
+          }
         } else {
           stats = s;
           properDirectoryListingAndStaticFileServe();

src/utils/generateServerStringCore.js

@@ -0,0 +1,22 @@
+const svrjsCoreInfo = require("../../svrjs.core.json");
+const { name } = svrjsCoreInfo;
+const svrjsInfo = require("../../svrjs.json");
+const { version } = svrjsInfo;
+const getOS = require("./getOS.js");
+
+function generateServerString(exposeServerVersion) {
+  return exposeServerVersion
+    ? `${name.replace(/ /g, "-")}/${version} (${getOS()}; ${
+        process.isBun
+          ? "Bun/v" + process.versions.bun + "; like Node.JS/" + process.version
+          : process.versions && process.versions.deno
+            ? "Deno/v" +
+              process.versions.deno +
+              "; like Node.JS/" +
+              process.version
+            : "Node.JS/" + process.version
+      })`
+    : name.replace(/ /g, "-");
+}
+
+module.exports = generateServerString;

svrjs.core.json

@@ -0,0 +1,25 @@
+{
+  "name": "SVR.JS Core",
+  "externalPackages": ["mime-types"],
+  "packageJSON": {
+    "name": "svrjs-core",
+    "description": "A library for static file serving, built from SVR.JS source code.",
+    "repository": {
+      "type": "git",
+      "url": "https://git.svrjs.org/svrjs/svrjs.git"
+    },
+    "keywords": [
+      "static",
+      "web",
+      "server",
+      "files",
+      "mime",
+      "middleware"
+    ],
+    "homepage": "https://svrjs.org",
+    "license": "MIT",
+    "engines": {
+      "node": ">=10.0.0"
+    }
+  }
+}