Postman test script to check the mime type of file based on it content

Question

I have an API where I can upload the file and it returns the metadata of the file uploaded. I want to make a postman test that can check the content of the file and detect the metadata. The metadata it detected should be compared with the metadata that is shown in the response body.

Please note: my API accepts every kind of files like text, image, pdf, video, etc.

const fs = require('fs');

pm.test('File content matches MIME type', async () => {
  const filePath = pm.response.toFile();

  try {
    const data = await fs.promises.readFile(filePath);
    const magicNumber = data.slice(0, 4).toString('hex');
    const expectedType = mime.getType(magicNumber);

    pm.expect(expectedType).toEqual(pm.response.get('Content-Type'));
  } catch (error) {
    pm.expect.fail(`Error reading file: ${error}`);
  }
});

This passes all the test. For example, I changed the extension of text to .img but it still pass. I also tried editing the mime type and included the GIF mime type in .txt file, it still pass. The script should fail if the mime type is different. Sorry for the English.