address come comments

crates/bevy_log/src/lib.rs

@@ -120,6 +120,7 @@ pub struct LogPlugin {
  /// ## Platform-specific
  ///
  /// **`WASM`** does not support logging to a file.
+ #[cfg(not(target_arch = "wasm32"))]
  pub file_appender_settings: Option<FileAppenderSettings>,
 }
 
@@ -171,14 +172,20 @@ struct FileAppenderWorkerGuard(tracing_appender::non_blocking::WorkerGuard);
 #[derive(Debug, Clone)]
 pub struct FileAppenderSettings {
  /// Controls how often a new file will be created
+ ///
+ /// Defaults to [`Rolling::Never`]
  pub rolling: Rolling,
  /// The path of the directory where the log files will be added
  ///
  /// Defaults to the local directory
  pub path: PathBuf,
  /// The prefix added when creating a file
+ ///
+ /// Defaults to "log"
  pub prefix: String,
  /// When this is enabled, a panic hook will be used and any panic will be logged as an error
+ ///
+ /// Defaults to true
  pub use_panic_hook: bool,
 }
 
@@ -263,16 +270,14 @@ impl Plugin for LogPlugin {
  meta.fields().field("tracy.frame_mark").is_none()
  }));
 
- let subscriber = subscriber.with(fmt_layer);
-
  #[cfg(feature = "tracing-chrome")]
  let subscriber = subscriber.with(chrome_layer);
  #[cfg(feature = "tracing-tracy")]
  let subscriber = subscriber.with(tracy_layer);
- subscriber
+ subscriber.with(fmt_layer)
  };
 
- let file_appender_layer = if let Some(settings) = &self.file_appender_settings {
+ let file_appender_layer = self.file_appender_settings.as_ref().map(|settings| {
  if settings.use_panic_hook {
  let old_handler = std::panic::take_hook();
  std::panic::set_hook(Box::new(move |panic_info| {
@@ -286,7 +291,7 @@ impl Plugin for LogPlugin {
  }
 
  if settings.rolling == Rolling::Never && settings.prefix.is_empty() {
- panic!("Using the Rolling::Never variant with no prefix will result in an empty filename which is invalid");
+ panic!("Using the Rolling::Never variant with no prefix will result in an empty filename, which is invalid");
  }
  let file_appender = tracing_appender::rolling::RollingFileAppender::new(
  settings.rolling.into(),
@@ -299,13 +304,10 @@ impl Plugin for LogPlugin {
  // If it gets dropped then it will silently stop writing to the file
  app.insert_resource(FileAppenderWorkerGuard(worker_guard));
 
- let file_fmt_layer = tracing_subscriber::fmt::Layer::default()
+ tracing_subscriber::fmt::Layer::default()
  .with_ansi(false)
- .with_writer(non_blocking);
- Some(file_fmt_layer)
- } else {
- None
- };
+ .with_writer(non_blocking)
+ });
  let subscriber = subscriber.with(file_appender_layer);
 
  #[cfg(feature = "tracing-chrome")]

examples/app/logs.rs

@@ -1,6 +1,7 @@
 //! This example illustrates how to use logs in bevy.
 
 use bevy::log::once;
+use bevy::log::FileAppenderSettings;
 use bevy::prelude::*;
 
 fn main() {