DataTransferItem: метод getAsFileSystemHandle()

getAsFileSystemHandle()

elem.addEventListener("dragover", (e) => {
  // Prevent navigation.
  e.preventDefault();
});
elem.addEventListener("drop", async (e) => {
  // Prevent navigation.
  e.preventDefault();

  // Process all of the items.
  for (const item of e.dataTransfer.items) {
    // kind will be 'file' for file/directory entries.
    if (item.kind === "file") {
      const entry = await item.getAsFileSystemHandle();
      if (entry.kind === "file") {
        // run code for if entry is a file
      } else if (entry.kind === "directory") {
        // run code for is entry is a directory
      }
    }
  }
});