---
name: configured-logger-close
group: api
category: runtime
update-time: 20260613
description: Close the configured runtime logger sink and return whether the wrapped RuntimeSink reported a successful close action.
key-word:
    - logger
    - runtime
    - lifecycle
    - public
---

## Configured-logger-close

Close the sink behind a `ConfiguredLogger`. This helper is the configured logger wrapper over `RuntimeSink::close(...)` for config-driven runtime teardown.

### Interface

```moonbit
pub fn ConfiguredLogger::close(self : ConfiguredLogger) -> Bool {}
```

#### input

- `self : ConfiguredLogger` - Config-driven runtime logger whose sink should be closed.

#### output

- `Bool` - Whether the wrapped `RuntimeSink::close(...)` call reported a successful close action.

### Explanation

Detailed rules explaining key parameters and behaviors

- This helper delegates directly to `self.sink.close()`.
- Plain file sinks forward to `FileSink::close()` through `RuntimeSink`.
- Queue-backed file sinks close the wrapped file sink instead of only the queue wrapper.
- Generic `close()` on queued file sinks does not drain pending queue entries first; it closes the wrapped file sink directly.
- Console-style sinks and queue-wrapped console-style sinks return `true` as a no-op success because they do not expose a meaningful close step here.
- For file-backed configured loggers, later `close()` calls return `false` after the wrapped file handle has already been cleared.

### How to Use

Here are some specific examples provided.

#### When Need Config-driven Runtime Teardown

When a config-built logger should release its sink resources:
```moonbit
ignore(logger.close())
```

In this example, sink teardown happens through the configured logger facade.

#### When Need To Observe Close Outcome

When application code wants a success flag from runtime close behavior:
```moonbit
let closed = logger.close()
```

In this example, callers can branch on the reported close result.

### Error Case

e.g.:
- If the configured runtime sink shape has no real close action, the helper may still return `true` as a no-op success.

- If the configured logger shares the same wrapped runtime sink state with another facade and one path already closed that file-backed sink, a later close attempt returns `false`.

- If callers need a file-specific close path with queue flush nuances, `file_close()` may be the better API.

### Notes

1. This is the generic configured runtime close helper.

2. Prefer `file_close()` when the configured sink shape is file-backed and queued records should be flushed before teardown.

3. Converting the same configured logger through wrapper paths such as library projection still shares the wrapped runtime sink state, so close effects are visible across those facades.