I have the following code:

const getFromFirebase = () => {
    //1.
    let storageRef = storage.ref(`${user1}/${currentItem.id}`);
    //2.
    storageRef.listAll().then(function (res) {
        //3.
        res.items.forEach((imageRef) => {
          imageRef.getDownloadURL().then((url) => {
              //4.
              if (allImages.indexOf(url) === -1) {
              setImages((allImages) => [...allImages, ({Test : url, Test2 : imageRef.name})]);
              }
          });
        });
        
      })
      .catch(function (error) {
        console.log(error);
      });
  };

I am calling this function on a tab onclick - it works in that it shows the documents but if I click the tab again it simply repeats itself - how do I run a check that if all documents are showing already to not double up?