Question about file type and cancell upload?

[robokonk]

Hello

#1 I see on formidable documentation, that we can check file type:

const options = {
  filter: function ({name, originalFilename, mimetype}) {
    // keep only images
    return mimetype && mimetype.includes("image");
  }
};

When I should put this code?

app.post("/api/upload", async (req, res, next) => {
  const options = {
    filter: function ({ name, originalFilename, mimetype }) {
      // keep only images
      return mimetype && mimetype.includes("image");
    },
  };

  const form = formidable({
    multiples: true,
    uploadDir: "./uploads",
    maxFileSize: 1024 * 1024,
    options,
  });

Code in this place is not working.

#2 I have another question, how I can cancel upload when file type is not image?

  const form = formidable({
    multiples: true,
    uploadDir: "./uploads",
 
  });

  const uploadDirIndex = fs.readdirSync(form.uploadDir).length + 1;

  form.on("file", async (field, file) => {
    if (file.mimetype.includes("image")) {
      const fileExtension = path.extname(file.originalFilename);
      const fileNewName = `avatar-${uploadDirIndex}${fileExtension}`;
      fs.rename(file.filepath, form.uploadDir + "/" + fileNewName, () => {
        console.log(`test ${file.originalFilename.split(" ").join("")}`);
      });
    } else {
      console.log("error format");
        file.destroy();
    }
  });

At the moment this is my code and is working by file.destroy(), but I see that first file was upload, and next deleted.
I want before upload, stopped when file is not image.

[GrosSacASac]

It is working for me, what version do you have make sure to have at least v3