Don't allow overwrite of files/directories using move()

Depends on D150663

Differential Revision: https://phabricator.services.mozilla.com/D157643

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1791384
gecko-commit: e0355ac9047673122eb9bc6876a06d4c5ddcd79d
gecko-reviewers: dom-storage-reviewers, jari

Author: Randell Jesup

fs/script-tests/FileSystemFileHandle-move.js

@@ -86,10 +86,11 @@ directory_test(async (t, root) => {
   await promise_rejects_dom(
       t, 'NoModificationAllowedError', handle.move('file-after'));
 
-  // Can move handle once the writable is closed.
+  // Can't move handle once the writable is closed.
   await stream.close();
-  await handle.move('file-after');
-  assert_array_equals(await getSortedDirectoryEntries(root), ['file-after']);
+  await promise_rejects_dom(
+      t, 'NoModificationAllowedError', handle.move('file-after'));
+  assert_array_equals(await getSortedDirectoryEntries(root), ['file-before']);
 }, 'move(name) while the destination file has an open writable fails');
 
 
@@ -308,15 +309,11 @@ directory_test(async (t, root) => {
   // Assert the file is still in the source directory.
   assert_array_equals(await getSortedDirectoryEntries(dir_src), ['file']);
 
-  // Can move handle once the writable is closed.
+  // Can't move handle once the writable is closed.
   await stream.close();
-  await file.move(dir_dest);
-  assert_array_equals(
-      await getSortedDirectoryEntries(root), ['dir-dest/', 'dir-src/']);
-  assert_array_equals(await getSortedDirectoryEntries(dir_src), []);
-  assert_array_equals(await getSortedDirectoryEntries(dir_dest), ['file']);
-  assert_equals(await getFileContents(file), 'abc');
-  assert_equals(await getFileSize(file), 3);
+  await promise_rejects_dom(
+      t, 'NoModificationAllowedError', file.move(dir_dest));
+  assert_array_equals(await getSortedDirectoryEntries(dir_src), ['file']);
 }, 'move(dir) while the destination file has an open writable fails');
 
 directory_test(async (t, root) => {
@@ -336,13 +333,12 @@ directory_test(async (t, root) => {
   // Assert the file is still in the source directory.
   assert_array_equals(await getSortedDirectoryEntries(dir_src), ['file-src']);
 
-  // Can move handle once the writable is closed.
+  // Can't move handle once the writable is closed.
   await stream.close();
-  await file.move(dir_dest, 'file-dest');
-  assert_array_equals(
-      await getSortedDirectoryEntries(root), ['dir-dest/', 'dir-src/']);
-  assert_array_equals(await getSortedDirectoryEntries(dir_src), []);
-  assert_array_equals(await getSortedDirectoryEntries(dir_dest), ['file-dest']);
+  await promise_rejects_dom(
+      t, 'NoModificationAllowedError', file.move(dir_dest, 'file-dest'));
+  // Assert the file is still in the source directory.
+  assert_array_equals(await getSortedDirectoryEntries(dir_src), ['file-src']);
   assert_equals(await getFileContents(file), 'abc');
   assert_equals(await getFileSize(file), 3);
 }, 'move(dir, name) while the destination file has an open writable fails');