Parse FormData object in nest controller - json

Question

I have a nest controller which accepts the following DTO, One of the parameters should be a buffer which is read from file
It suppose to read bin file
interface LoadFileRequest {
targetIp: string;
fileBuffer: Buffer;
user: User;
}
interface User {
username: string;
password: string;
}
#Controller('loader')
export class KeyLoaderController {
#Post('load')
async load(#Body() body: LoadFileRequest, #Req() request) {
console.log(body);
console.log(request);
}
}
My code for testing the controller:
import axios from "axios";
import fs from "fs";
import FormData from "form-data";
let headersList = {
Accept: "*/*",
};
let formdata = new FormData();
formdata.append("targetIP", "10.10.1.145");
formdata.append(
"user",
JSON.stringify({
username: "user",
password: "auth",
})
);
formdata.append("fileBuffer", fs.createReadStream("test.bin"));
let bodyContent = formdata;
const url = "http://localhost:3000/loader/load";
let reqOptions = {
url,
method: "POST",
headers: headersList,
data: { bodyContent },
};
axios.request(reqOptions).then(function (response) {
console.log(response.data);
});
At the controller this is the request body i get
{
bodyContent: {
_overheadLength: 380,
_valueLength: 48,
_valuesToMeasure: [ [Object] ],
writable: false,
readable: true,
dataSize: 0,
maxDataSize: 2097152,
pauseStreams: true,
_released: false,
_streams: [
'----------------------------092840744027446269037569\r\n' +
'Content-Disposition: form-data; name="targetIP"\r\n' +
'\r\n',
'10.10.1.145',
null,
'----------------------------092840744027446269037569\r\n' +
'Content-Disposition: form-data; name="user"\r\n' +
'\r\n',
'{"username":"user","password":"auth"}',
null,
'----------------------------092840744027446269037569\r\n' +
'Content-Disposition: form-data; name="fileBuffer"; filename="test.bin"\r\n' +
'Content-Type: application/octet-stream\r\n' +
'\r\n',
[Object],
null
],
_currentStream: null,
_insideLoop: false,
_pendingNext: false,
_boundary: '--------------------------092840744027446269037569'
}
}
How can i get the body in the form of object with only the attrbutes of the DTO?
Eventually i got a method which recived the same type of object and i want to call it like this:
#Controller('loader')
export class KeyLoaderController {
#Post('load')
async load(#Body() body: LoadFileRequest, #Req() request) {
return await loadFile(body);
}
}
EDIT:
I changed the code a bit and now if i send the request from VS code thunder client it works fine(sort of):
#Controller('loader')
export class KeyLoaderController {
#Post('load')
#UseInterceptors(FileInterceptor('fileBuffer'))
async load(#Body() body, #UploadedFile() file) {
console.log(body);
console.log(file);
}
}
When I send this way (The code on the right is the generated code by the extension, Which does not act the same way when I use it):
This is the body and file I get:
[Object: null prototype] {
targetIP: '10.10.1.145',
user: '{ "username": "user", "password": "0123456789"}'
}
{
fieldname: 'fileBuffer',
originalname: 'test.bin',
encoding: '7bit',
mimetype: 'application/octet-stream',
buffer: <Buffer ... ... 119 more bytes>, size: 169
}
But when i take the code i generated in VS code thunder client (which is at axios request in this post) I still get the body like before (again, as mention in the post)

Answer 1

If you're sending a multipart/form-data request, you need a form data body parser installed on the server. You can either use the FileInterceptor (or one of the derivatives of it), or bind multer as a middleware for the entire server. This will allow for the parsing of multipart/form-data requests.
In your axios call, remove the brackets around bodyContent so it becomes data: bodyContent. You aren't sending an object of form data you are just sending formdata itself