How to restrict some file types from uploading in google-cloud-storage, and also determine if the file is a document or an image?

I am using the code as given in the firebase storage documentation to upload files to my project.

Here is the code:

var metadata = {
  contentType: 'image/jpeg'
};

var uploadTask = storageRef.child('images/' + file.name).put(file, metadata);

uploadTask.on(firebase.storage.TaskEvent.STATE_CHANGED, 
  (snapshot) => {
  
    var progress = (snapshot.bytesTransferred / snapshot.totalBytes) * 100;
    console.log('Upload is ' + progress + '% done');
    switch (snapshot.state) {
      case firebase.storage.TaskState.PAUSED: 
        console.log('Upload is paused');
        break;
      case firebase.storage.TaskState.RUNNING: 
        console.log('Upload is running');
        break;
    }
  }, 
  (error) => {
    switch (error.code) {
      case 'storage/unauthorized':
        // User doesn't have permission to access the object
        break;
      case 'storage/canceled':
        // User canceled the upload
        break;

      // ...

      case 'storage/unknown':
        // Unknown error occurred, inspect error.serverResponse
        break;
    }
  }, 
  () => {
    uploadTask.snapshot.ref.getDownloadURL().then((downloadURL) => {
      console.log('File available at', downloadURL);
    });
  }
);

I want to add some functionalities. The first functionality is that I could determine whether the file being uploaded is a document or a photo. The second functionality is that I will only allow pdf and jpeg format files to be uploaded.

In order to achieve these functionalities does firebase storage provides any function or do I need to manually determine the file type from the file name by using the split function?