# Error Handling

## Handling errors within selectors

```ts
@State({ ... })
class AppState {
  @Selector()
  static getCount(state: StateModel) {
    return state.count.number.value;
  }
}
```

Let's take a look at the below example:

```ts
this.store.reset({}); // reset all states
```

The catch is that when resetting the entire state, the object will no longer have those deeply nested properties (`state.count.number.value`). Given the following code:

```ts
const state = {};

function getCount() {
  return state.count.number.value;
}

const count = getCount(); // will throw
```

RxJS will automatically complete the stream under the hood if any error is thrown.

You have to disable suppressing errors using the `suppressErrors` option:

```ts
@NgModule({
  imports: [
    NgxsModule.forRoot([CountState], {
      selectorOptions: {
        suppressErrors: false
      }
    })
  ]
})
export class AppModule {}
```

This option allows to track errors and handle them.

```ts
@State({ ... })
class AppState {
  @Selector()
  static getCount(state: StateModel) {
    try {
      return state.count.number.value;
    } catch (error) {
      console.log('error', error);
      // throw error;
      // Automatic unsubscription will occur if you use the `throw` statement here. Skip it if you don't want the stream to be completed on error.
    }
  }
}
```

#### Why does RxJS unsubscribe on error?

RxJS [design guidelines](https://github.com/ReactiveX/rxjs/blob/master/docs_app/content/guide/observable.md#executing-observables) provides a great explanation of this behavior.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://www.ngxs.io/concepts/select/error-handling.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.