# unnecessary_null_assert_pattern

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



_The null-assert pattern will have no effect because the matched type isn't nullable._

## Description

The analyzer produces this diagnostic when a null-assert pattern is used
to match a value that isn't nullable.

## Example

The following code produces this diagnostic because the variable `x` isn't
nullable:

```dart
void f(int x) {
  if (x case var a[!!!] when a > 0) {}
}
```

## Common fixes

Remove the null-assert pattern:

```dart
void f(int x) {
  if (x case var a when a > 0) {}
}
```

