fix: handle getAsFileSystemHandle resolving to null and close #106

src/file-selector.spec.ts

@@ -333,6 +333,13 @@ it('should not use getAsFileSystemHandle when not in a secure context', async ()
     window.isSecureContext = true;
 });
 
+it('should reject when getAsFileSystemHandle resolves to null', async () => {
+    const evt = dragEvtFromItems([
+        dataTransferItemWithFsHandle(null, null)
+    ]);
+    expect(fromEvent(evt)).rejects.toMatch('is not a File');
+});
+
 function dragEvtFromItems(items: DataTransferItem | DataTransferItem[], type: string = 'drop'): DragEvent {
     return {
         type,
@@ -403,7 +410,7 @@ function dataTransferItemFromEntry(entry: FileEntry | DirEntry, file?: File): Da
     } as any;
 }
 
-function dataTransferItemWithFsHandle(file?: File, h?: FileSystemFileHandle): DataTransferItem {
+function dataTransferItemWithFsHandle(file?: File | null, h?: FileSystemFileHandle | null): DataTransferItem {
     return {
         kind: 'file',
         getAsFile() {
@@ -510,7 +517,7 @@ function sortFiles<T extends File>(files: T[]) {
 
 
 interface FileSystemFileHandle {
-    getFile(): Promise<File>;
+    getFile(): Promise<File | null>;
 }
 
 type FileOrDirEntry = FileEntry | DirEntry

src/file-selector.ts

@@ -130,19 +130,26 @@ function fromDataTransferItem(item: DataTransferItem, entry?: FileSystemEntry |
     if (globalThis.isSecureContext && typeof (item as any).getAsFileSystemHandle === 'function') {
         return (item as any).getAsFileSystemHandle()
             .then(async (h: any) => {
+                if (!h) {
+                    return notAFile(item);
+                }
                 const file = await h.getFile();
                 file.handle = h;
                 return toFileWithPath(file);
             });
     }
     const file = item.getAsFile();
     if (!file) {
-        return Promise.reject(`${item} is not a File`);
+        return notAFile(item);
     }
     const fwp = toFileWithPath(file, entry?.fullPath ?? undefined);
     return Promise.resolve(fwp);
 }
 
+function notAFile(item: DataTransferItem) {
+    return Promise.reject(`${item} is not a File`);
+}
+
 // https://developer.mozilla.org/en-US/docs/Web/API/FileSystemEntry
 async function fromEntry(entry: any) {
     return entry.isDirectory ? fromDirEntry(entry) : fromFileEntry(entry);