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File content missing when i download from s3

I am using node.js aws sdk for s3 related methods. I have a method to download the file from s3 bucket.
I am downloading the file using the below code.
const downloadFileBase64 = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
const response = await s3
.getObject(params, (err) => {
if (err) {
return err;
}
})
.promise();
return {
data: response.Body.toString('base64'),
fileName: payload.fileName
};
} catch (error) {
return Boom.badRequest(error.message);
}
};
Once i get the base64 content i am sending it over an email using sendgrid.
Issue: When i download small files everything is working fine. But when i download large files, some part of the file is missing in multiple pages. I just copy pasted the base64 in few online websites and downloaded the file from there, it's the same issue in those websites also. With this i concluded that there is some issue while returning the response from s3 itself. When i go to s3 and check it in the folder, it's showing proper file.
If you see the above screenshot, its the pdf which is having some random grey background in few pages and some text is also missing from the pdf.
I tried to use another method which just download buffer excluding the base64 conversion as shown below.
const downloadFileBuffer = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
const response = await s3
.getObject(params, (err) => {
if (err) {
return err;
}
})
.promise();
return {
data: response.Body,
fileName: payload.fileName
};
} catch (error) {
return Boom.badRequest(error.message);
}
};
And once i get the file content in this above response, i am storing temporarily in a folder on server and then reading again and sending over email. But i am still having the same issue.
const fileContent = await docs.downloadFileBuffer({ payload: req.payload.action.dire });
await fs.writeFileSync(`${temp}testinggg.pdf`, fileContent?.data);
const fileData = await fs.readFileSync(`${temp}testinggg.pdf`, { encoding: 'base64' });
Any help on this issue is really appreciated.

After days of research and trying different ways, I found the issue. The issue was with .promise() used in s3.getObject(params, (err) => {}).promise();. Instead of that, I used callback using Promise as shown below. Now the file is properly showing the full content without missing any data.
const downloadFileBuffer = async (payload) => {
let params = { Bucket: s3BucketName, Key: `${payload.folderName}/${payload.fileName}` };
try {
return new Promise((resolve, reject) => {
s3.getObject(params, (err, response) => {
if (err) {
reject(err);
}
resolve({
data: response.Body,
fileName: payload.fileName
});
});
});
} catch (error) {
return Boom.badRequest(error.message);
}
};

How do I get uploaded image in next js and save it?

How do I get uploaded image in next.js API route and save it on public folder? I have front end ready. I'm uploading images to an endpoint using plain JavaScript.
here is the onSubmit function for uploading images. Suggest me if I'm doing it wrong here. The main question is how do I retrieve it?
const onSubmit=async(e)=>{
e.preventDefault();
const fd=new FormData()
fd.append('myfile',image.name)
let res=await fetch(`http://localhost:3000/api/upload`,{
method: 'POST',
headers: {
"Content-Type": "image/jpeg",
},
body: fd,
})
let response=await res.json();
one more bonus question, it's surely not a good idea to save the uploaded images on public folder. I have save it somewhere on the cloud.

This is the endpoint code I used for uploading image in nextjs, it requires some additional packages I will list them bellow also.
next-connect
multer
uuid
import nextConnect from "next-connect";
import multer from "multer";
import { v4 as uuidv4 } from "uuid";
let filename = uuidv4() + "-" + new Date().getTime();
const upload = multer({
storage: multer.diskStorage({
destination: "./public/uploads/profiles", // destination folder
filename: (req, file, cb) => cb(null, getFileName(file)),
}),
});
const getFileName = (file) => {
filename +=
"." +
file.originalname.substring(
file.originalname.lastIndexOf(".") + 1,
file.originalname.length
);
return filename;
};
const apiRoute = nextConnect({
onError(error, req, res) {
res
.status(501)
.json({ error: `Sorry something Happened! ${error.message}` });
},
onNoMatch(req, res) {
res.status(405).json({ error: `Method '${req.method}' Not Allowed` });
},
});
apiRoute.use(upload.array("file")); // attribute name you are sending the file by
apiRoute.post((req, res) => {
res.status(200).json({ data: `/uploads/profiles/${filename}` }); // response
});
export default apiRoute;
export const config = {
api: {
bodyParser: false, // Disallow body parsing, consume as stream
},
};

no Need to use any packages to handle file uploading you can use base64 to convert file to string and return it back to file by using "fs" module
why This way is beterr then using formData ?
because you duleing with normal post request where you can send any kind of data with it and use body parsere .
converting
const toBase64 = (file: File) => new Promise((resolve, reject) => {
const reader = new FileReader();
reader.readAsDataURL(file);
reader.onload = () => resolve(reader.result);
reader.onerror = error => reject(error);
}
send a post request to server
const base64: string = await toBase64(file) as string;
const fileData = { base64, fileName: file.name };
const result = await api.post("/foo", fileData, name: "Salih", massage: "Hello World"})
converting base64 to file in server
function base64ToFile(file: { base64: string, fileName: string }) {
const fileContents = file.base64.replace(/^data:image\/png;base64,/, "");
fs.mkdirSync("./public/uploads", { recursive: true });
const fileName = `./public/uploads/${Date.now().toString() + file.fileName}`
fs.writeFile(fileName, fileContents, 'base64', function (err) { console.log(err) });
}

I suggest the popular and lightweight formidable library:
# install
yarn add formidable#v3 #types/formidable
// pages/api/file-upload.ts
import fs from "fs";
import path from "path";
import { File } from "formidable";
// Important for NextJS!
export const config = {
api: {
bodyParser: false,
},
};
export default async function handler(
req: NextApiRequest,
res: NextApiResponse<string>
) {
try {
// Parse request with formidable
const { fields, files } = await parseFormAsync(req);
// Files are always arrays (formidable v3+)
const myfile = (files["myfile"] as any as File[])[0];
// Save file in the public folder
saveFile(myfile, "./public/uploads");
// Return success
res.status(200).json("success!");
} catch (e) {
return res.status(500).json(e);
}
}
function saveFile(file: File, publicFolder: string): void {
const fileExt = path.extname(file.originalFilename || "");
fs.renameSync(file.filepath, `${publicFolder}/${file.newFilename}${fileExt}`);
}
// ./helpers/formidable.ts
import type { NextApiRequest } from "next";
import formidable from "formidable";
export type FormidableParseReturn = {
fields: formidable.Fields;
files: formidable.Files;
};
export async function parseFormAsync(
req: NextApiRequest,
formidableOptions?: formidable.Options
): Promise<FormidableParseReturn> {
const form = formidable(formidableOptions);
return await new Promise<FormidableParseReturn>((resolve, reject) => {
form.parse(req, async (err, fields, files) => {
if (err) {
reject(err);
}
resolve({ fields, files });
});
});
}
Bonus question
one more bonus question, it's surely not a good idea to save the uploaded images on public folder. I have save it somewhere on the cloud.
S3 and other cloud services
You can save on cloud services with Formidable.
See the official examples: https://github.com/node-formidable/formidable/blob/master/examples/store-files-on-s3.js
But you don't need to use cloud storage to protect private uploads. You can store them locally.
Working with private uploads locally
Saving:
Store the uploads in a non-public folder;
Ex. /private-uploads/{logged_user_id}/;
Reading:
Create an API page to fetch the file
Ex. https://.../uploads/{filename}
Fail if the file doesn't belong to the authenticated user;
Send the file as the response;
Security:
With the above folder scheme, hackers can use .. and similar on the filename to obtain unauthorized access;
Sanitize the filename having this in mind (ex. only allow alphanumeric characters);
Alternatively, use a database table to control ownership instead of a folder scheme;

PouchDB can't convert blob into url for image src

Hey guys I'm working with PouchDB and react. File uploading is working normally but when I try to convert blob into url I'm having this error in console.
"Failed to execute 'createObjectURL' on 'URL': Overload resolution
failed."
I checked the return and I'm able to retrieve all the data/images into the console and basically see the file types and so on. Anyway I heard that "createObjectURL" is deprecated or so but I followed up the tutorial provided in docs for the PouchDB. So I'm not sure now. Can someone give me any insights or help on this ? Thanks
Snippet below:
// uploading files
const uploadF = e => {
// saving chosen file
const file = e.target.files[0];
// generating random number and converting it to the string
const random_id = Math.floor(Math.random() * 10000);
const random_id_to_string = String(random_id);
console.log(file);
// insert data into local DB
db.post({
_id: random_id_to_string,
_attachments: {
fileName: {
content_type: file.type,
data: file
}
}
})
// insert data into remote db
redb.post({
_id: random_id_to_string,
_attachments: {
fileName: {
content_type: file.type,
data: file
}
}
})
// upload file to s3 bucket
S3FileUpload.uploadFile(e.target.files[0],config)
.then(data => {
console.log(data);
})
.catch(err => console.log(err))
}
// retrieve all data from db
const files = [];
db.allDocs({
include_docs: true,
attachments: true
}).then(function (result) {
return result;
})
.then(function(blob){
const url = URL.createObjectURL(blob);
console.log(url);
})
.catch(function (err) {
console.log(err);
});
return(
<section className="hero">
<nav>
<h2>Welcome</h2>
<button onClick={handleLogout}>Logout</button>
<input type="file" onChange={e => uploadF(e)} />
</nav>
</section>
);

AWS S3 file upload with Node.js: Unsupported body payload error

I am trying to get my node.js backend to upload a file to AWS S3, which it got in a post request from my front-end. This is what my function looks like:
async function uploadFile(file){
var uploadParams = {Bucket: '<bucket-name>', Key: file.name, Body: file};
s3.upload (uploadParams, function (err, data) {
if (err) {
console.log("Error", err);
} if (data) {
console.log("Upload Success", data.Location);
}
});
}
When I try uploading the file this way, I get an Unsupported Body Payload Error...
I used fileStream.createReadStream() in the past to upload files saves in a directory on the server, but creating a fileStream did not work for me, since there is no path parameter to pass here.
EDIT:
The file object is created in the angular frontend of my web application. This it the relevant html code where the file is uploaded by a user:
<div class="form-group">
<label for="file">Choose File</label>
<input type="file" id="file"(change)="handleFileInput($event.target.files)">
</div>
If the event occurs, the handleFileInput(files: FileList) method in the corresponding component is called:
handleFileInput(files: FileList) {
// should result in array in case multiple files are uploaded
this.fileToUpload = files.item(0);
// actually upload the file
this.uploadFileToActivity();
// used to check whether we really received the file
console.log(this.fileToUpload);
console.log(typeof this.fileToUpload)
}
uploadFileToActivity() {
this.fileUploadService.postFile(this.fileToUpload).subscribe(data => {
// do something, if upload success
}, error => {
console.log(error);
});
}
the postFile(fileToUpload: File) method of the file-upload service is used to make the post request:
postFile(fileToUpload: File): Observable<Boolean> {
console.log(fileToUpload.name);
const endpoint = '/api/fileupload/single';
const formData: FormData = new FormData();
formData.append('fileKey', fileToUpload, fileToUpload.name);
return this.httpClient
.post(endpoint, formData/*, { headers: yourHeadersConfig }*/)
.pipe(
map(() => { return true; }),
catchError((e) => this.handleError(e)),
);
}
Here is the the server-side code that receives the file and then calls the uploadFile(file) function:
app.post('/api/fileupload/single', async (req, res) => {
try {
if(!req.files) {
res.send({
status: false,
message: 'No file uploaded'
});
} else {
let file = req.files.fileKey;
uploadFile(file);
//send response
res.send({
status: true,
message: 'File is uploaded',
data: {
name: file.name,
mimetype: file.mimetype,
size: file.size
}
});
}
} catch (err) {
res.status(500).send(err);
}
});
Thank you very much for your help in solving this!
Best regards, Samuel

Best way is stream the file. Assuming you are. reading it from disk. You could do this
const fs = require("fs");
const aws = require("aws-sdk");
const s3Client = new aws.S3();
const Bucket = 'somebucket';
const stream = fs.createReadStream("file.pdf");
const Key = stream.path;
const response = await s3Client.upload({Bucket, Key, Body: stream}).promise();
console.log(response);

Uploading multiple large json files in one go React-native to NodeJS

I am trying to upload multiple large size JSON files from React-native to node js.
The files are being uploaded unless the file in larger in size, in which case, it does not upload in one try.
I suspect that:
Since the upload code is in a for loop the code is starting the upload but not waiting for the file to upload and starting to upload the next file
Is there any way to ensure that each file gets uploaded in one go?
syncFunction() {
var RNFS = require('react-native-fs');
var path = RNFS.DocumentDirectoryPath + '/toBeSynced';
RNFS.readDir(path)
.then((success) => {
for (let i = 0; i < success.length; i++) {
var fileName = success[i].name
var filePath = success[i].path
var uploadUrl = 'http://192.168.1.15:3333/SurveyJsonFiles/GetFiles/'
if (Platform.OS === 'android') {
filePath = filePath.replace("file://", "")
} else if (Platform.OS === 'ios') {
filePath = filePath
}
const data = new FormData();
data.append("files", {
uri: filePath,
type: 'multipart/form-data',
name: fileName,
});
const config = {
method: 'POST',
headers: {
'Accept': 'application/json',
},
body: data,
};
fetch(uploadUrl, config)
.then((checkStatusAndGetJSONResponse) => {
console.log(checkStatusAndGetJSONResponse);
this.moveFile(filePath, fileName)
}).catch((err) => {
console.log(err)
});
}
})
.catch((err) => {
console.log(err.message);
});
}
The JSON files will more than 50Mb depending on data, since it contains base64 image data the size will increase as the user takes more photos.
The app will be creating new files when the user records any information, There is no error message displayed for partial file upload.
The this.moveSyncedFiles() is moving the synced files to another folder so that the same file does not get uploaded multiple times
moveFile(oldpath, oldName) {
var syncedPath = RNFS.DocumentDirectoryPath + '/syncedFiles'
RNFS.mkdir(syncedPath)
syncedPath = syncedPath + "/" + oldName
RNFS.moveFile(oldpath, syncedPath)
.then((success) => {
console.log("files moved successfully")
})
.catch((err) => {
console.log(err.message)
});
}

It turns out the fault was on the nodejs side and nodemon was restarting the server every time a new file was found so we just moved the uploads folder outside the scope of the project