busboy on field and on file not firing

Question

It worked yesterday, and now it stopped without any changes made to the code. What is going on?

Client

async function uploadFile(file) {
    let formData = new FormData();

    formData.append("recordUid", recordUid);
    formData.append("fieldUid", fieldUid);
    formData.append("file", file);

    await fetchPostFormData("/api/files", formData);
}

async function fetchPostFormData(url, formData) {);
    try {
        let result = await (
            await fetch(url, {
                method: "POST",
                withCredentials: true,
                credentials: "include",
                headers: {
                    Authorization: localStorage.getItem("token"),
                },
                body: formData,
            })
        ).json();

        return result;
    } catch (err) {
        return err;
    }
}

Server

router.post("/api/files", async (req, res, next) => {
    try {
        console.log("starting upload..."); // <------------------- THIS ONE IS LOGGED

        let bb = busboy({
            headers: req.headers,
            limits: {
                fileSize: 20 * 1024 * 1024, // 20 mb
            },
        });

        let fields = {};

        // Get any text values
        bb.on("field", (fieldname, val, fieldnameTruncated, valTruncated) => {

            console.log("on.field", fieldname, val); // <------------------ NOT FIRING

            fields[fieldname] = val;
        });

        bb.on("file", (fieldname, file, filename, encoding, mimetype) => {

            console.log("on.file"); // <----------------------------------- NOT FIRING

            let parts = filename.filename.split(".");
            let name = parts[0];
            let extension = parts[parts.length - 1];

            let finalName = `${+new Date()}-${name}.${extension}`;
            let filePath = `${filesFolderPath}${finalName}`;

            // Open writeable stream to path
            let writeStream = fs.createWriteStream(filePath);

            // Pipe the file to the opened stream
            file.pipe(writeStream);

            // Check for errors
            writeStream.on("error", (err) => {
                console.log(err);
            });

            writeStream.on("close", async (err) => {
                let sizeBytes = fs.statSync(filePath).size;
            });
        });

        bb.on("finish", () => {
            res.status(200).send({ success: true });
        });
    } catch (err) {
        next(err);
    }
});

Answer 1

Managed to solve it.

The problem was the missing req.pipe(bb) at the very end.

        // previous code... ^^^^^

        bb.on("finish", () => {
            res.status(200).send({ success: true });
        });

        req.pipe(bb)  // <------------- THIS SHIT RIGHT HERE

    } catch (err) {
        next(err);
    }
});