Update DataTransfer.Files upon change to it's items list

Refactored "blink::DataTransfer" class to update "files_" member when it's DataObject's item list is changed, instead of doing the same in the files getter. This change ensures that files is updated immediately when the DataTransfer's item list changes. This fixes the issue where if a reference to DataTransfer.files is stored in a separate JS variable, then any file items added to that DataTransfer object are not reflected in the stored JS variable, until the DataTransfer object's files getter is invoked. The issue is not present in Safari and Firefox. Bug: 342067834 Change-Id: Id59ca73ae0e8b744b247f1eabba9f70565245433 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5973363 Reviewed-by: Christine Hollingsworth <christinesm@chromium.org> Commit-Queue: Rohan Raja <roraja@microsoft.com> Reviewed-by: Ayu Ishii <ayui@chromium.org> Cr-Commit-Position: refs/heads/main@{#1382128}
web-platform-tests · Nov 13, 2024 · 6094964 · 6094964
1 parent 84f13be
commit 6094964
Showing 1 changed file with 19 additions and 0 deletions.
diff --git a/clipboard-apis/data-transfer-file-list-change-reference-updates.html b/clipboard-apis/data-transfer-file-list-change-reference-updates.html
@@ -0,0 +1,19 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Any JS reference DataTransfer.files should contain latest changes done to DataTransfer.items</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<input type=file multiple>
+<script>
+  test(() => {
+    const dt = new DataTransfer();
+    const filelist = dt.files;
+    assert_equals(
+      filelist.length, 0,
+      'Initial filelist should be empty');
+    dt.items.add(new File([0], 'test'));
+    assert_equals(
+      filelist.length, 1,
+      'Filelist should reflect the changes done to items');
+  }, 'expect changed contents');
+</script>