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fix(flutter): prevent ConcurrentModificationError in SignalsMixin #436

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Merged
rodydavis merged 1 commit into from
Dec 19, 2025
Merged

fix(flutter): prevent ConcurrentModificationError in SignalsMixin #436

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16 changes: 11 additions & 5 deletions packages/signals_flutter/lib/src/mixins/signals.dart
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Original file line number Diff line number Diff line change
Expand Up @@ -64,7 +64,10 @@ mixin SignalsMixin<T extends StatefulWidget> on State<T> {
void _setup() {
WidgetsBinding.instance.addPostFrameCallback((_) {
final cb = effect(() {
for (final s in _signals.values.where((e) => e.local != null)) {
// Snapshot to prevent ConcurrentModificationError if value access
// triggers bindSignal() which mutates _signals during iteration
final signals = _signals.values.where((e) => e.local != null).toList();
for (final s in signals) {
s.target.value;
}
_rebuild();
Expand Down Expand Up @@ -385,14 +388,17 @@ mixin SignalsMixin<T extends StatefulWidget> on State<T> {
void clearSignalsAndEffects() {
_cleanup?.call();
_cleanup = null;
final local = _signals //
.values
// Snapshot collections to prevent ConcurrentModificationError
// dispose() and effect cleanup can trigger mutations
final local = _signals.values
.where((e) => e.local == true)
.map((e) => e.target);
.map((e) => e.target)
.toList();
for (final s in local) {
s.dispose();
}
for (final cb in _effects) {
final effects = List<EffectCleanup>.of(_effects);
for (final cb in effects) {
cb();
}
_effects.clear();
Expand Down