# cancel_subscriptions

> Details about the cancel_subscriptions diagnostic produced by the Dart analyzer.



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_Uncancelled instance of 'StreamSubscription'._

## Description

The analyzer produces this diagnostic when an instance of
`StreamSubscription` is created but the method `cancel` isn't invoked.

## Example

The following code produces this diagnostic because the `subscription`
isn't canceled:

```dart
import 'dart:async';

void f(Stream stream) {
  // ignore: unused_local_variable
  var [!subscription = stream.listen((_) {})!];
}
```

## Common fixes

Cancel the subscription:

```dart
import 'dart:async';

void f(Stream stream) {
  var subscription = stream.listen((_) {});
  subscription.cancel();
}
```

