I'm making a function that permits me to upload a picture to imgur in my express api (nodejs), i'm encoutering an error when calling a function returning a promise:
TypeError: res.status is not a function at uploadpicture.then
This is my code: Where error is raised:
router.post('/upload', (req, res, next)=> {
var busboy = new Busboy({headers: req.headers});
busboy.on('file', function(fieldname, file, filename, encoding, mimetype) {
if(fieldname == 'image') {
// the buffer
file.fileRead = [];
file.on('data', function(data) {
// add to the buffer as data comes in
this.fileRead.push(data);
});
file.on('end', function() {
// create a new stream with our buffered data
var finalBuffer = Buffer.concat(this.fileRead);
upload = uploadpicture(finalBuffer).then((res)=>{ //success request
console.log(res);
res.status(200).json({success: true, message: "Successfully uploaded !", url: res.data.link});
},(err)=>{ //error
res.status(500).json({success: false, message: "Error happenned while uploading !"});
}).catch((error)=>{
console.log(error);
res.status(500).json({success: false, message: "Error happenned while uploading !"});
});
})
}
});
busboy.on('finish', function() {
//busboy finished
});
req.pipe(busboy);
});
And the function :
function uploadpicture(stream){ //get picture stream
return new Promise((resolve, reject)=>{
var options = {
uri: 'https://api.imgur.com/3/image',
method: 'POST',
headers: {
//'Authorization': 'Client-ID ' + config.client_id_imgur // put client id here
},
formData: {
image: stream,
type: 'file'
},
auth: {
bearer: config.access_token_imgur,
}
};
request(options)
.then((parsedBody)=> {
resolve(parsedBody);
})
.catch((err)=> {
console.log(err);
reject(err.toString())
});
});
}
The code works perfectly, but i don't know why suddendly this error happened, i tried to :
change arrow functions to function(){} Add next to the route parameters
Nothing worked, Thanks for your help
Conclusion # The "response. json is not a function" error occurs when we call the json() method on an object that is not the Response object that resolves from the promise the fetch() method returns, or call the json() method on the return value from calling an axios method.
The res. status() function set the HTTP status for the response. It is a chainable alias of Node's response.
The "Cannot set headers after they are sent to the client" error occurs when the server in an express. js application sends more than one response for a single request, e.g. calling res. json() twice. To solve the error, make sure to only send a single response for each request.
The accepted answer directly addresses the OP's problem, but I post another solution since you can also encounter this error in other places.
When you have:
api.use((error: ErrorRequestHandler, request: ExpressRequest, response: ExpressResponse) => {
response.status(500).end() // response.status is not a function
})
Because the error handling route must accept 4 arguments for express to identify it as an error middleware.
api.use((error: ErrorRequestHandler, request: ExpressRequest, response: ExpressResponse, next: NextFunction) => {
response.status(500).end()
})
Just adding the next function (or whatever argument you're missing) will fix it.
https://github.com/visionmedia/supertest/issues/416#issuecomment-514508137
At this point:
upload = uploadpicture(finalBuffer).then((res)=>{ //success request
the res
is the result of promise uploadpicture
function (that is the parsedBody
), not the res
from the express route. So indeed, it has no status
function. Try change the then
callback name like:
upload = uploadpicture(finalBuffer).then((otherName)=>{ //success request
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