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[flutter_tools] Safely remove web loading indicator on dart-app-ready - #192233
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When the debug WebSocket connection temporarily drops and reconnects,
DWDS dispatches a subsequent 'dart-app-ready' event. Previously, the event
listener in the bootstrapping script directly called
`loader.parentNode.removeChild(loader)`, which caused an unhandled TypeError
("Cannot read properties of null (reading 'removeChild')") on subsequent
events because the loader had already been detached.
Configure the 'dart-app-ready' event listener with `{ once: true }` so it
runs at most once, and use `loader.remove()` and `styleSheet.remove()` to safely
remove the elements without relying on `parentNode`.
Fixes flutter#192226
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This pull request updates the web bootstrap script generation to use Element.remove() instead of parentNode.removeChild() for removing the loader and stylesheet elements, and configures the 'dart-app-ready' event listener to trigger only once by passing the { once: true } option. Corresponding unit tests have been added to verify these changes. I have no feedback to provide.
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flutter/flutter@63170e9...b444e78 2026-09-08 [email protected] Clean up lint errors in workflows (flutter/flutter#191987) 2026-09-08 [email protected] Remove no-shuffle tag from dropdown_test.dart (flutter/flutter#186398) 2026-09-08 [email protected] Remove no-shuffle from scrollbar test (flutter/flutter#186656) 2026-09-08 [email protected] [tool] Let --local-engine reach the build system again (flutter/flutter#192361) 2026-09-08 [email protected] [flutter_tools] Safely remove web loading indicator on dart-app-ready (flutter/flutter#192233) 2026-09-08 [email protected] [Linux] Don't clear the OpenGL context when a frame has been drawn (flutter/flutter#192137) 2026-09-08 [email protected] ci: update dartdoc from 9.0.6 to 9.0.9 (flutter/flutter#192405) 2026-09-07 [email protected] Add itemExtentBuilder support to ListView.separated (flutter/flutter#191157) 2026-09-07 [email protected] Roll Skia from e1437642d259 to b3fa80a0e168 (5 revisions) (flutter/flutter#192362) 2026-09-07 [email protected] Roll Skia from 2df865d9d369 to e1437642d259 (1 revision) (flutter/flutter#192360) 2026-09-07 [email protected] Roll Skia from c7aa5512d148 to 2df865d9d369 (2 revisions) (flutter/flutter#192357) 2026-09-06 [email protected] Roll Skia from db200e27a634 to c7aa5512d148 (2 revisions) (flutter/flutter#192351) 2026-09-06 [email protected] Roll Fuchsia Linux SDK from _IgixhH4vEgdz9Oqn... to p8hHkUi8uWT9R3N4z... (flutter/flutter#192349) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
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…r#12791) flutter/flutter@63170e9...b444e78 2026-09-08 [email protected] Clean up lint errors in workflows (flutter/flutter#191987) 2026-09-08 [email protected] Remove no-shuffle tag from dropdown_test.dart (flutter/flutter#186398) 2026-09-08 [email protected] Remove no-shuffle from scrollbar test (flutter/flutter#186656) 2026-09-08 [email protected] [tool] Let --local-engine reach the build system again (flutter/flutter#192361) 2026-09-08 [email protected] [flutter_tools] Safely remove web loading indicator on dart-app-ready (flutter/flutter#192233) 2026-09-08 [email protected] [Linux] Don't clear the OpenGL context when a frame has been drawn (flutter/flutter#192137) 2026-09-08 [email protected] ci: update dartdoc from 9.0.6 to 9.0.9 (flutter/flutter#192405) 2026-09-07 [email protected] Add itemExtentBuilder support to ListView.separated (flutter/flutter#191157) 2026-09-07 [email protected] Roll Skia from e1437642d259 to b3fa80a0e168 (5 revisions) (flutter/flutter#192362) 2026-09-07 [email protected] Roll Skia from 2df865d9d369 to e1437642d259 (1 revision) (flutter/flutter#192360) 2026-09-07 [email protected] Roll Skia from c7aa5512d148 to 2df865d9d369 (2 revisions) (flutter/flutter#192357) 2026-09-06 [email protected] Roll Skia from db200e27a634 to c7aa5512d148 (2 revisions) (flutter/flutter#192351) 2026-09-06 [email protected] Roll Fuchsia Linux SDK from _IgixhH4vEgdz9Oqn... to p8hHkUi8uWT9R3N4z... (flutter/flutter#192349) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
victorsanni
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to victorsanni/packages
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Sep 9, 2026
…r#12791) flutter/flutter@63170e9...b444e78 2026-09-08 [email protected] Clean up lint errors in workflows (flutter/flutter#191987) 2026-09-08 [email protected] Remove no-shuffle tag from dropdown_test.dart (flutter/flutter#186398) 2026-09-08 [email protected] Remove no-shuffle from scrollbar test (flutter/flutter#186656) 2026-09-08 [email protected] [tool] Let --local-engine reach the build system again (flutter/flutter#192361) 2026-09-08 [email protected] [flutter_tools] Safely remove web loading indicator on dart-app-ready (flutter/flutter#192233) 2026-09-08 [email protected] [Linux] Don't clear the OpenGL context when a frame has been drawn (flutter/flutter#192137) 2026-09-08 [email protected] ci: update dartdoc from 9.0.6 to 9.0.9 (flutter/flutter#192405) 2026-09-07 [email protected] Add itemExtentBuilder support to ListView.separated (flutter/flutter#191157) 2026-09-07 [email protected] Roll Skia from e1437642d259 to b3fa80a0e168 (5 revisions) (flutter/flutter#192362) 2026-09-07 [email protected] Roll Skia from 2df865d9d369 to e1437642d259 (1 revision) (flutter/flutter#192360) 2026-09-07 [email protected] Roll Skia from c7aa5512d148 to 2df865d9d369 (2 revisions) (flutter/flutter#192357) 2026-09-06 [email protected] Roll Skia from db200e27a634 to c7aa5512d148 (2 revisions) (flutter/flutter#192351) 2026-09-06 [email protected] Roll Fuchsia Linux SDK from _IgixhH4vEgdz9Oqn... to p8hHkUi8uWT9R3N4z... (flutter/flutter#192349) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md
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Fixes #192226
Problem
In
packages/flutter_tools/lib/src/web/bootstrap.dart, when compiling the web bootstrap script (main.dart.js), an event listener was added towindowfordart-app-readythat executed:On initial load, this removes the loader from the DOM, setting
loader.parentNodetonull.When DWDS reconnects or re-dispatches
dart-app-ready(e.g. following a WebSocket disconnect/reconnect), this listener was invoked again. Attempting to call.removeChildon anullparentNodethrew:Solution
loader.remove()andstyleSheet.remove()instead ofparentNode.removeChild().{ once: true }so it is automatically removed after firing once.Tests
Added regression unit tests to
packages/flutter_tools/test/general.shard/web/bootstrap_test.dartverifying that{ once: true }and.remove()are used in generated web bootstrap code.