Move cache folder out of tmp by default

README.md

@@ -18,7 +18,7 @@
 
 No setup needed. Codebook will automatically detect the language you are editing and mark issues for you. Note, Codebook will only mark issues for words that you control, where they are initially defined.
 
-Please gift us a ⭐ if you find Codebook useful!
+Please gift a ⭐ if you find Codebook useful!
 
 ## Integrations
 

crates/codebook-config/src/helpers.rs

@@ -2,7 +2,60 @@ use crate::settings::ConfigSettings;
 use glob::Pattern;
 use log::error;
 use regex::Regex;
-use std::path::Path;
+use std::env;
+use std::path::{Path, PathBuf};
+
+pub(crate) fn default_cache_dir() -> PathBuf {
+    #[cfg(windows)]
+    {
+        windows_cache_dir()
+    }
+
+    #[cfg(not(windows))]
+    {
+        unix_cache_dir()
+    }
+}
+
+#[cfg(windows)]
+pub(crate) fn windows_cache_dir() -> PathBuf {
+    if let Some(dir) = dirs::data_local_dir() {
+        return dir.join("codebook").join("cache");
+    }
+
+    if let Some(dir) = dirs::data_dir() {
+        return dir.join("codebook").join("cache");
+    }
+
+    if let Some(home) = dirs::home_dir() {
+        return home
+            .join("AppData")
+            .join("Local")
+            .join("codebook")
+            .join("cache");
+    }
+
+    env::temp_dir().join("codebook").join("cache")
+}
+
+#[cfg(not(windows))]
+pub(crate) fn unix_cache_dir() -> PathBuf {
+    if let Some(xdg_data_home) = env::var_os("XDG_DATA_HOME")
+        && !xdg_data_home.is_empty()
+    {
+        return PathBuf::from(xdg_data_home).join("codebook").join("cache");
+    }
+
+    if let Some(home) = dirs::home_dir() {
+        return home
+            .join(".local")
+            .join("share")
+            .join("codebook")
+            .join("cache");
+    }
+
+    env::temp_dir().join("codebook").join("cache")
+}
 
 /// Insert a word into the allowlist, returning true when it was newly added.
 pub(crate) fn insert_word(settings: &mut ConfigSettings, word: &str) -> bool {
@@ -77,3 +130,82 @@ pub(crate) fn build_ignore_regexes(patterns: &[String]) -> Vec<Regex> {
 pub(crate) fn min_word_length(settings: &ConfigSettings) -> usize {
     settings.min_word_length
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::ffi::OsString;
+    use std::sync::{Mutex, MutexGuard};
+
+    #[cfg(not(windows))]
+    static ENV_MUTEX: Mutex<()> = Mutex::new(());
+
+    #[cfg(not(windows))]
+    fn lock_env_and_set_xdg(value: Option<&str>) -> (MutexGuard<'static, ()>, Option<OsString>) {
+        let guard = ENV_MUTEX.lock().unwrap();
+        let previous = env::var_os("XDG_DATA_HOME");
+
+        unsafe {
+            match value {
+                Some(val) => env::set_var("XDG_DATA_HOME", val),
+                None => env::remove_var("XDG_DATA_HOME"),
+            }
+        }
+
+        (guard, previous)
+    }
+
+    #[cfg(not(windows))]
+    fn restore_xdg(previous: Option<OsString>) {
+        unsafe {
+            match previous {
+                Some(val) => env::set_var("XDG_DATA_HOME", val),
+                None => env::remove_var("XDG_DATA_HOME"),
+            }
+        }
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn unix_cache_dir_uses_xdg_data_home() {
+        let (guard, previous) = lock_env_and_set_xdg(Some("/tmp/codebook-xdg"));
+
+        let expected = PathBuf::from("/tmp/codebook-xdg")
+            .join("codebook")
+            .join("cache");
+
+        assert_eq!(unix_cache_dir(), expected);
+
+        restore_xdg(previous);
+        drop(guard);
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn unix_cache_dir_falls_back_to_home() {
+        let (guard, previous) = lock_env_and_set_xdg(Some(""));
+
+        let home = dirs::home_dir().expect("home directory must be available for the test");
+        let expected = home
+            .join(".local")
+            .join("share")
+            .join("codebook")
+            .join("cache");
+
+        assert_eq!(unix_cache_dir(), expected);
+
+        restore_xdg(previous);
+        drop(guard);
+    }
+
+    #[cfg(not(windows))]
+    #[test]
+    fn default_cache_dir_matches_unix_on_non_windows() {
+        let (guard, previous) = lock_env_and_set_xdg(Some("/tmp/codebook-xdg-default"));
+
+        assert_eq!(default_cache_dir(), unix_cache_dir());
+
+        restore_xdg(previous);
+        drop(guard);
+    }
+}

crates/codebook-config/src/lib.rs

@@ -64,7 +64,7 @@ impl Default for CodebookConfigFile {
 
         Self {
             inner: RwLock::new(inner),
-            cache_dir: env::temp_dir().join(CACHE_DIR),
+            cache_dir: helpers::default_cache_dir(),
         }
     }
 }
@@ -508,7 +508,7 @@ impl Default for CodebookConfigMemory {
     fn default() -> Self {
         Self {
             settings: RwLock::new(ConfigSettings::default()),
-            cache_dir: env::temp_dir().join(CACHE_DIR),
+            cache_dir: helpers::default_cache_dir(),
         }
     }
 }
@@ -517,7 +517,7 @@ impl CodebookConfigMemory {
     pub fn new(settings: ConfigSettings) -> Self {
         Self {
             settings: RwLock::new(settings),
-            cache_dir: env::temp_dir().join(CACHE_DIR),
+            cache_dir: helpers::default_cache_dir(),
         }
     }
 }