feat(logger): delete old logs & avoid more dup logs (#4348)

* feat(logger): delete old logs & avoid more dup logs

* `match` -> `let else` where possible

4 files changed, 341 insertions, 59 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 674467534..85d2892c6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ license = "ISC"
 readme = "README.md"
 repository = "https://github.com/starship/starship"
 # Note: MSRV is only intended as a hint, and only the latest version is officially supported in starship.
-rust-version = "1.64"
+rust-version = "1.65"
 description = """
 The minimal, blazing-fast, and infinitely customizable prompt for any shell! ☄🌌️
 """
diff --git a/src/logger.rs b/src/logger.rs
index ca0c21be1..7e86c10b6 100644
--- a/src/logger.rs
+++ b/src/logger.rs
@@ -3,48 +3,109 @@ use log::{Level, LevelFilter, Metadata, Record};
 use nu_ansi_term::Color;
 use once_cell::sync::OnceCell;
 use std::{
+    cmp,
     collections::HashSet,
     env,
     fs::{self, File, OpenOptions},
     io::Write,
-    path::PathBuf,
-    sync::Mutex,
+    path::{Path, PathBuf},
+    sync::{Mutex, RwLock},
 };
 
 pub struct StarshipLogger {
     log_file: OnceCell<Mutex<File>>,
     log_file_path: PathBuf,
-    log_file_content: HashSet<String>,
+    log_file_content: RwLock<HashSet<String>>,
     log_level: Level,
 }
 
+/// Returns the path to the log directory.
+pub fn get_log_dir() -> PathBuf {
+    env::var_os("STARSHIP_CACHE")
+        .map(PathBuf::from)
+        .unwrap_or_else(|| {
+            utils::home_dir()
+                .map(|home| home.join(".cache"))
+                .or_else(dirs_next::cache_dir)
+                .unwrap_or_else(std::env::temp_dir)
+                .join("starship")
+        })
+}
+
+/// Deletes all log files in the log directory that were modified more than 24 hours ago.
+pub fn cleanup_log_files<P: AsRef<Path>>(path: P) {
+    let log_dir = path.as_ref();
+    let log_files = match fs::read_dir(log_dir) {
+        Ok(log_files) => log_files,
+        // Avoid noisily handling errors in this cleanup function.
+        Err(_) => return,
+    };
+
+    for file in log_files {
+        // Skip files that can't be read.
+        let Ok (file) = file else {
+            continue;
+        };
+
+        // Avoid deleting files that don't look like log files.
+        if !file
+            .path()
+            .file_name()
+            .unwrap_or_default()
+            .to_str()
+            .unwrap_or_default()
+            .starts_with("session_")
+            || file.path().extension() != Some("log".as_ref())
+        {
+            continue;
+        }
+
+        // Read metadata to check file age.
+        let Ok(metadata) = file.metadata() else {
+            continue;
+        };
+
+        // Avoid handling anything that isn't a file.
+        if !metadata.is_file() {
+            continue;
+        }
+
+        // Get the file's modification time.
+        let Ok(modified) = metadata.modified() else {
+            continue;
+        };
+
+        // Delete the file if it hasn't changed in 24 hours.
+        if modified.elapsed().unwrap_or_default().as_secs() > 60 * 60 * 24 {
+            let _ = fs::remove_file(file.path());
+        }
+    }
+}
+
 impl Default for StarshipLogger {
     fn default() -> Self {
-        let log_dir = env::var_os("STARSHIP_CACHE")
-            .map(PathBuf::from)
-            .unwrap_or_else(|| {
-                utils::home_dir()
-                    .expect("Unable to find home directory")
-                    .join(".cache/starship")
-            });
-
-        fs::create_dir_all(&log_dir)
-            .unwrap_or_else(|err| panic!("Unable to create log dir {log_dir:?}: {err:?}!"));
+        let log_dir = get_log_dir();
+
+        if let Err(err) = fs::create_dir_all(&log_dir) {
+            eprintln!("Unable to create log dir {log_dir:?}: {err:?}!")
+        };
         let session_log_file = log_dir.join(format!(
             "session_{}.log",
             env::var("STARSHIP_SESSION_KEY").unwrap_or_default()
         ));
 
         Self {
-            log_file_content: fs::read_to_string(&session_log_file)
-                .unwrap_or_default()
-                .lines()
-                .map(std::string::ToString::to_string)
-                .collect(),
+            log_file_content: RwLock::new(
+                fs::read_to_string(&session_log_file)
+                    .unwrap_or_default()
+                    .lines()
+                    .map(std::string::ToString::to_string)
+                    .collect(),
+            ),
             log_file: OnceCell::new(),
             log_file_path: session_log_file,
             log_level: env::var("STARSHIP_LOG")
-                .map(|level| match level.to_lowercase().as_str() {
+                .map(|level| match level.to_ascii_lowercase().as_str() {
                     "trace" => Level::Trace,
                     "debug" => Level::Debug,
                     "info" => Level::Info,
@@ -66,6 +127,12 @@ impl StarshipLogger {
     /// Override the log level path
     /// This won't change anything if a log file was already opened
     pub fn set_log_file_path(&mut self, path: PathBuf) {
+        let contents = fs::read_to_string(&path)
+            .unwrap_or_default()
+            .lines()
+            .map(std::string::ToString::to_string)
+            .collect();
+        self.log_file_content = RwLock::new(contents);
         self.log_file_path = path;
     }
 }
@@ -76,6 +143,11 @@ impl log::Log for StarshipLogger {
     }
 
     fn log(&self, record: &Record) {
+        // Early return if the log level is not enabled
+        if !self.enabled(record.metadata()) {
+            return;
+        }
+
         let to_print = format!(
             "[{}] - ({}): {}",
             record.level(),
@@ -83,51 +155,84 @@ impl log::Log for StarshipLogger {
             record.args()
         );
 
-        if record.metadata().level() <= Level::Warn {
-            self.log_file
-                .get_or_try_init(|| {
-                    let m = Mutex::new(
-                        OpenOptions::new()
-                            .create(true)
-                            .append(true)
-                            .open(&self.log_file_path)?,
-                    );
-                    Ok(m)
-                })
-                .unwrap_or_else(|err: std::io::Error| {
-                    panic!(
+        // A log message is only printed or written to the log file,
+        // if it's not already in the log file or has been printed in this session.
+        // To help with debugging, duplicate detection only runs if the log level is warn or lower
+        let is_debug = record.level() > Level::Warn;
+        let is_duplicate = {
+            !is_debug
+                && self
+                    .log_file_content
+                    .read()
+                    .map(|c| c.contains(to_print.as_str()))
+                    .unwrap_or(false)
+        };
+
+        if is_duplicate {
+            return;
+        }
+
+        // Write warning messages to the log file
+        // If log level is error, only write error messages to the log file
+        if record.level() <= cmp::min(Level::Warn, self.log_level) {
+            let log_file = match self.log_file.get_or_try_init(|| {
+                OpenOptions::new()
+                    .create(true)
+                    .append(true)
+                    .open(&self.log_file_path)
+                    .map(Mutex::new)
+            }) {
+                Ok(log_file) => log_file,
+                Err(err) => {
+                    eprintln!(
                         "Unable to open session log file {:?}: {err:?}!",
                         self.log_file_path
-                    )
-                })
-                .lock()
-                .map(|mut file| writeln!(file, "{to_print}"))
-                .expect("Log file writer mutex was poisoned!")
-                .expect("Unable to write to the log file!");
+                    );
+                    return;
+                }
+            };
+
+            let mut file_handle = match log_file.lock() {
+                Ok(file_handle) => file_handle,
+                Err(err) => {
+                    eprintln!("Log file writer mutex was poisoned! {err:?}",);
+                    return;
+                }
+            };
+            if let Err(err) = writeln!(file_handle, "{to_print}") {
+                eprintln!("Unable to write to session log file {err:?}!",);
+            };
         }
 
-        if self.enabled(record.metadata()) && !self.log_file_content.contains(to_print.as_str()) {
-            eprintln!(
-                "[{}] - ({}): {}",
-                match record.level() {
-                    Level::Trace => Color::Blue.dimmed().paint(format!("{}", record.level())),
-                    Level::Debug => Color::Cyan.paint(format!("{}", record.level())),
-                    Level::Info => Color::White.paint(format!("{}", record.level())),
-                    Level::Warn => Color::Yellow.paint(format!("{}", record.level())),
-                    Level::Error => Color::Red.paint(format!("{}", record.level())),
-                },
-                record.module_path().unwrap_or_default(),
-                record.args()
-            );
+        // Print messages to stderr
+        eprintln!(
+            "[{}] - ({}): {}",
+            match record.level() {
+                Level::Trace => Color::Blue.dimmed().paint(format!("{}", record.level())),
+                Level::Debug => Color::Cyan.paint(format!("{}", record.level())),
+                Level::Info => Color::White.paint(format!("{}", record.level())),
+                Level::Warn => Color::Yellow.paint(format!("{}", record.level())),
+                Level::Error => Color::Red.paint(format!("{}", record.level())),
+            },
+            record.module_path().unwrap_or_default(),
+            record.args()
+        );
+
+        // Add to duplicate detection set
+        if let Ok(mut c) = self.log_file_content.write() {
+            c.insert(to_print);
         }
     }
 
     fn flush(&self) {
         if let Some(m) = self.log_file.get() {
-            m.lock()
-                .map(|mut writer| writer.flush())
-                .expect("Log file writer mutex was poisoned!")
-                .expect("Unable to flush the log file!");
+            let result = match m.lock() {
+                Ok(mut file) => file.flush(),
+                Err(err) => return eprintln!("Log file writer mutex was poisoned: {err:?}"),
+            };
+            if let Err(err) = result {
+                eprintln!("Unable to flush the log file: {err:?}");
+            }
         }
     }
 }
@@ -136,3 +241,171 @@ pub fn init() {
     log::set_boxed_logger(Box::<StarshipLogger>::default()).unwrap();
     log::set_max_level(LevelFilter::Trace);
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::utils::read_file;
+    use log::Log;
+    use std::io;
+
+    #[test]
+    fn test_log_to_file() -> io::Result<()> {
+        let log_dir = tempfile::tempdir()?;
+        let log_file = log_dir.path().join("test.log");
+
+        let mut logger = StarshipLogger::default();
+        logger.set_log_file_path(log_file.clone());
+        logger.set_log_level(Level::Warn);
+
+        // Load at all log levels
+        logger.log(
+            &Record::builder()
+                .level(Level::Error)
+                .args(format_args!("error"))
+                .build(),
+        );
+        logger.log(
+            &Record::builder()
+                .level(Level::Warn)
+                .args(format_args!("warn"))
+                .build(),
+        );
+        logger.log(
+            &Record::builder()
+                .level(Level::Info)
+                .args(format_args!("info"))
+                .build(),
+        );
+        logger.log(
+            &Record::builder()
+                .level(Level::Debug)
+                .args(format_args!("debug"))
+                .build(),
+        );
+        logger.log(
+            &Record::builder()
+                .level(Level::Trace)
+                .args(format_args!("trace"))
+                .build(),
+        );
+
+        // Print duplicate messages
+        logger.log(
+            &Record::builder()
+                .level(Level::Warn)
+                .args(format_args!("warn"))
+                .build(),
+        );
+        logger.log(
+            &Record::builder()
+                .level(Level::Error)
+                .args(format_args!("error"))
+                .build(),
+        );
+
+        logger.flush();
+        drop(logger);
+
+        let content = read_file(log_file)?;
+
+        assert_eq!(content, "[ERROR] - (): error\n[WARN] - (): warn\n");
+
+        log_dir.close()
+    }
+
+    #[test]
+    fn test_dedup_from_file() -> io::Result<()> {
+        let log_dir = tempfile::tempdir()?;
+        let log_file = log_dir.path().join("test.log");
+        {
+            let mut file = File::create(&log_file)?;
+            file.write_all(b"[WARN] - (): warn\n")?;
+            file.sync_all()?;
+        }
+
+        let mut logger = StarshipLogger::default();
+        logger.set_log_file_path(log_file.clone());
+        logger.set_log_level(Level::Warn);
+
+        // This message should not be printed or written to the log file
+        logger.log(
+            &Record::builder()
+                .level(Level::Warn)
+                .args(format_args!("warn"))
+                .build(),
+        );
+        // This message should be printed and written to the log file
+        logger.log(
+            &Record::builder()
+                .level(Level::Warn)
+                .args(format_args!("warn2"))
+                .build(),
+        );
+
+        logger.flush();
+        drop(logger);
+
+        let content = read_file(log_file)?;
+
+        assert_eq!(content, "[WARN] - (): warn\n[WARN] - (): warn2\n");
+
+        log_dir.close()
+    }
+
+    #[test]
+    #[cfg(unix)]
+    fn test_cleanup() -> io::Result<()> {
+        use nix::sys::{stat::utimes, time::TimeVal};
+        use std::fs::File;
+
+        let log_dir = tempfile::tempdir()?;
+
+        // Should not be deleted
+        let non_matching_file = log_dir.path().join("non-matching.log");
+        let non_matching_file2 = log_dir.path().join("session_.exe");
+        let new_file = log_dir.path().join("session_new.log");
+        let directory = log_dir.path().join("session_dir.log");
+
+        // Should be deleted
+        let old_file = log_dir.path().join("session_old.log");
+
+        for file in &[
+            &non_matching_file,
+            &non_matching_file2,
+            &new_file,
+            &old_file,
+        ] {
+            File::create(file)?;
+        }
+        fs::create_dir(&directory)?;
+
+        // Set all files except the new file to be older than 24 hours
+        for file in &[
+            &non_matching_file,
+            &non_matching_file2,
+            &old_file,
+            &directory,
+        ] {
+            utimes(file.as_path(), &TimeVal::new(0, 0), &TimeVal::new(0, 0))?;
+            if let Ok(f) = File::open(file) {
+                f.sync_all()?;
+            }
+        }
+
+        cleanup_log_files(log_dir.path());
+
+        for file in &[
+            &non_matching_file,
+            &non_matching_file2,
+            &new_file,
+            &directory,
+        ] {
+            assert!(file.exists(), "File {file:?} should exist");
+        }
+
+        assert!(!old_file.exists(), "File {old_file:?} should not exist");
+
+        log_dir.close()
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 69bff9cfb..92cbe8c17 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -118,6 +118,12 @@ fn main() {
     logger::init();
     init_global_threadpool();
 
+    // Delete old log files
+    rayon::spawn(|| {
+        let log_dir = logger::get_log_dir();
+        logger::cleanup_log_files(log_dir);
+    });
+
     let args = match Cli::try_parse() {
         Ok(args) => args,
         Err(e) => {
diff --git a/src/test/mod.rs b/src/test/mod.rs
index c761bb981..c8e271e4b 100644
--- a/src/test/mod.rs
+++ b/src/test/mod.rs
@@ -10,6 +10,7 @@ use once_cell::sync::Lazy;
 use std::fs;
 use std::io;
 use std::path::{Path, PathBuf};
+use std::sync::Once;
 use tempfile::TempDir;
 
 static FIXTURE_DIR: Lazy<PathBuf> =
@@ -18,7 +19,9 @@ static FIXTURE_DIR: Lazy<PathBuf> =
 static GIT_FIXTURE: Lazy<PathBuf> = Lazy::new(|| FIXTURE_DIR.join("git-repo.bundle"));
 static HG_FIXTURE: Lazy<PathBuf> = Lazy::new(|| FIXTURE_DIR.join("hg-repo.bundle"));
 
-static LOGGER: Lazy<()> = Lazy::new(|| {
+static LOGGER: Once = Once::new();
+
+fn init_logger() {
     let mut logger = StarshipLogger::default();
 
     // Don't log to files during tests
@@ -31,7 +34,7 @@ static LOGGER: Lazy<()> = Lazy::new(|| {
     logger.set_log_file_path(nul);
 
     log::set_boxed_logger(Box::new(logger)).unwrap();
-});
+}
 
 pub fn default_context() -> Context<'static> {
     let mut context = Context::new_with_shell_and_path(
@@ -55,7 +58,7 @@ impl<'a> ModuleRenderer<'a> {
     /// Creates a new `ModuleRenderer`
     pub fn new(name: &'a str) -> Self {
         // Start logger
-        Lazy::force(&LOGGER);
+        LOGGER.call_once(init_logger);
 
         let context = default_context();