I am using the HTTP module of nodejs to create three routes('/','/about' and the last one treats any other route that is not defined as error route). When I access the root route first and try to access other route nodejs throw an error but when I access the error route or the about the route and try accessing another route it works fine.
Below are the code I wrote and the error nodejs throw
Error
PS C:\Users\Maxwell\Desktop\node> node app.js
node:events:368
^
Error [ERR_STREAM_WRITE_AFTER_END]: write after end
at new NodeError (node:internal/errors:371:5)
at ServerResponse.end (node:_http_outgoing:846:15)
at Server.<anonymous> (C:\Users\Maxwell\Desktop\node\app.js:10:9)
at Server.emit (node:events:390:28)
at parserOnIncoming (node:_http_server:951:12)
at HTTPParser.parserOnHeadersComplete (node:_http_common:128:17)
Emitted 'error' event on ServerResponse instance at:
at emitErrorNt (node:_http_outgoing:726:9)
at processTicksAndRejections (node:internal/process/task_queues:84:21) {
code: 'ERR_STREAM_WRITE_AFTER_END'
}
PS C:\Users\Maxwell\Desktop\node> node app.js
node:events:368
throw er; // Unhandled 'error' event
^
Error [ERR_STREAM_WRITE_AFTER_END]: write after end
at new NodeError (node:internal/errors:371:5)
at ServerResponse.end (node:_http_outgoing:846:15)
at Server.<anonymous> (C:\Users\Maxwell\Desktop\node\app.js:10:9)
at Server.emit (node:events:390:28)
at parserOnIncoming (node:_http_server:951:12)
at HTTPParser.parserOnHeadersComplete (node:_http_common:128:17)
Emitted 'error' event on ServerResponse instance at:
at emitErrorNt (node:_http_outgoing:726:9)
at processTicksAndRejections (node:internal/process/task_queues:84:21) {
code: 'ERR_STREAM_WRITE_AFTER_END'
}
Code
const http = require('http');
const server = http.createServer((req,res)=>{
if(req.url==='/'){
res.end('Welcome Home Dev, You are loved');
}
if(req.url==='/about'){
res.end('This is the about page')
}
res.end(
`<h1>OOOp</h1>
<p>It seen like this page does not exit</p>
<a href='/'>back to homepage</a>
`
);
});
server.listen(5000);
Change to an if/else so you're only processing one branch of the if per request:
const server = http.createServer((req,res)=>{
if(req.url === '/'){
res.end('Welcome Home Dev, You are loved');
} else if (req.url === '/about') {
res.end('This is the about page')
} else {
res.end(
`<h1>OOOp</h1>
<p>It seen like this page does not exit</p>
<a href='/'>back to homepage</a>`);
}
});
Or, alternately, you could add a return after each res.send() to stop further execution in your request handler after you send a response. Remember, that just because you call res.send() your function still continues to execute so you need to manage control flow so the other code that sends a response doesn't execute once you've already sent a response.