node.js TypeError: path must be absolute or specify root to res.sendFile [failed to parse JSON]


[add] So my next problem is that when i try adding a new dependence (npm install --save socket.io). The JSON file is also valid. I get this error: Failed to parse json

npm ERR! Unexpected string
npm ERR! File: /Users/John/package.json
npm ERR! Failed to parse package.json data.
npm ERR! package.json must be actual JSON, not just JavaScript.
npm ERR! 
npm ERR! This is not a bug in npm.
npm ERR! Tell the package author to fix their package.json file. JSON.parse 

So I've been trying to figure out why this error has been returning. All of the files (HTML,JSON,JS) are inside the same folder on my desktop. I'm using node.js and socket.io

This is my JS file:

var app = require('express')();
var http = require('http').Server(app);

app.get('/', function(req, res){
  res.sendFile('index.html');
});

http.listen(3000,function(){
    console.log('listening on : 3000');
});

This is what is getting returned:

MacBook-Pro:~ John$ node /Users/John/Desktop/Chatapp/index.js 
listening on : 3000
TypeError: path must be absolute or specify root to res.sendFile
    at ServerResponse.sendFile (/Users/John/node_modules/express/lib/response.js:389:11)
    at /Users/John/Desktop/Chatapp/index.js:5:7
    at Layer.handle [as handle_request] (/Users/John/node_modules/express/lib/router/layer.js:76:5)
    at next (/Users/John/node_modules/express/lib/router/route.js:100:13)
    at Route.dispatch (/Users/John/node_modules/express/lib/router/route.js:81:3)
    at Layer.handle [as handle_request] (/Users/John/node_modules/express/lib/router/layer.js:76:5)
    at /Users/John/node_modules/express/lib/router/index.js:234:24
    at Function.proto.process_params (/Users/John/node_modules/express/lib/router/index.js:312:12)
    at /Users/John/node_modules/express/lib/router/index.js:228:12
    at Function.match_layer (/Users/John/node_modules/express/lib/router/index.js:295:3)
TypeError: path must be absolute or specify root to res.sendFile
    at ServerResponse.sendFile (/Users/John/node_modules/express/lib/response.js:389:11)
    at /Users/John/Desktop/Chatapp/index.js:5:7
    at Layer.handle [as handle_request] (/Users/John/node_modules/express/lib/router/layer.js:76:5)
    at next (/Users/John/node_modules/express/lib/router/route.js:100:13)
    at Route.dispatch (/Users/John/node_modules/express/lib/router/route.js:81:3)
    at Layer.handle [as handle_request] (/Users/John/node_modules/express/lib/router/layer.js:76:5)
    at /Users/John/node_modules/express/lib/router/index.js:234:24
    at Function.proto.process_params (/Users/John/node_modules/express/lib/router/index.js:312:12)
    at /Users/John/node_modules/express/lib/router/index.js:228:12
    at Function.match_layer (/Users/John/node_modules/express/lib/router/index.js:295:3)

The error is pretty clear, you need to specify an absolute (instead of relative) path and/or set root in the config object for res.sendFile(). Examples:

// assuming index.html is in the same directory as this script

res.sendFile(__dirname + '/index.html');

or specify a root (which is used as the base path for the first argument to res.sendFile():

res.sendFile('index.html', { root: __dirname });

Specifying the root path is more useful when you're passing a user-generated file path which could potentially contain malformed/malicious parts like .. (e.g. ../../../../../../etc/passwd). Setting the root path prevents such malicious paths from being used to access files outside of that base path.


Try adding root path.

app.get('/', function(req, res) {
    res.sendFile('index.html', { root: __dirname });
});

in .mjs files we for now don't have __dirname

hence

res.sendFile('index.html', { root: '.' })

If you trust the path, path.resolve is an option:

var path = require('path');

// All other routes should redirect to the index.html
  app.route('/*')
    .get(function(req, res) {
      res.sendFile(path.resolve(app.get('appPath') + '/index.html'));
    });

The error is pretty straightforward. Most likely the reason is that your index.html file is not in the root directory.

Or if it is in the root directory then the relative referencing is not working.

So you need to tell the server exact location of your file. This could be done by using dirname method in NodeJs. Just replace your code with this one:

 app.get('/', function(req, res){
  res.sendFile(__dirname + '/index.html');
});

Make sure that your add the slash "/" symbol before your homepage. Otherwise your path will become: rootDirectoryindex.html

Whereas you want it to be: rootDirectory/index.html


I solve this by using path variable. The sample code will look like below.

var path = require("path");

app.get('/', (req, res) => {
    res.sendFile(path.join(__dirname + '/index.html'));
})

If you are working on Root Directory then you can use this approach

res.sendFile(__dirname + '/FOLDER_IN_ROOT_DIRECTORY/index.html');

but if you are using Routes which is inside a folder lets say /Routes/someRoute.js then you will need to do something like this

const path = require("path");
...
route.get("/some_route", (req, res) => {
   res.sendFile(path.resolve('FOLDER_IN_ROOT_DIRECTORY/index.html')
});


In Typescript with relative path to the icon:

import path from 'path';

route.get('/favicon.ico', (_req, res) => res.sendFile(path.join(__dirname, '../static/myicon.png')));

It will redirects to index.html on localhost:8080 call.

app.get('/',function(req,res){
    res.sendFile('index.html', { root: __dirname });
});

This can be resolved in another way:

app.get("/", function(req, res){

    res.send(`${process.env.PWD}/index.html`)

});

process.env.PWD will prepend the working directory when the process was started.


You might consider using double slashes on your directory e.g

app.get('/',(req,res)=>{
    res.sendFile('C:\\Users\\DOREEN\\Desktop\\Fitness Finder' + '/index.html')
})


I did this and now my app is working properly,

res.sendFile('your drive://your_subfolders//file.html');

I used the code below and tried to show the sitemap.xml file

router.get('/sitemap.xml', function (req, res) {
    res.sendFile('sitemap.xml', { root: '.' });
});