test: add unit tests for cache, session and config modules

cache.rs: make minimal_roots pub(crate); add 8 tests covering the
minimal_roots helper (empty input, single root, nested vs sibling dirs)
and validate_and_update (stale project removal, no-change short-circuit,
mtime-triggered rescan, legacy empty dir_mtimes).

session.rs: make session_name pub(crate); add 5 tests covering session
name sanitisation (dots→underscores, spaces→dashes, fallback for root
path) and TOML parsing for Window and SessionConfig with layout.

config.rs: add 3 tests covering serde defaults when optional fields are
absent, full config parsing and invalid TOML rejection.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/cache.rs

@@ -23,14 +23,20 @@ fn now_secs() -> u64 {
 }
 
 fn mtime_secs(time: SystemTime) -> u64 {
-    time.duration_since(UNIX_EPOCH).unwrap_or_default().as_secs()
+    time.duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_secs()
 }
 
 /// Retorna o subconjunto mínimo de diretórios: aqueles que não têm nenhum
 /// ancestral também na lista. Evita rescanear a mesma subárvore duas vezes.
-fn minimal_roots(dirs: &[PathBuf]) -> Vec<PathBuf> {
+pub(crate) fn minimal_roots(dirs: &[PathBuf]) -> Vec<PathBuf> {
     dirs.iter()
-        .filter(|dir| !dirs.iter().any(|other| other != *dir && dir.starts_with(other)))
+        .filter(|dir| {
+            !dirs
+                .iter()
+                .any(|other| other != *dir && dir.starts_with(other))
+        })
         .cloned()
         .collect()
 }
@@ -49,8 +55,9 @@ impl ProjectCache {
             .context("Could not determine cache directory")?
             .join("tmuxido");
 
-        fs::create_dir_all(&cache_dir)
-            .with_context(|| format!("Failed to create cache directory: {}", cache_dir.display()))?;
+        fs::create_dir_all(&cache_dir).with_context(|| {
+            format!("Failed to create cache directory: {}", cache_dir.display())
+        })?;
 
         Ok(cache_dir.join("projects.json"))
     }
@@ -74,8 +81,7 @@ impl ProjectCache {
     pub fn save(&self) -> Result<()> {
         let cache_path = Self::cache_path()?;
 
-        let content = serde_json::to_string_pretty(self)
-            .context("Failed to serialize cache")?;
+        let content = serde_json::to_string_pretty(self).context("Failed to serialize cache")?;
 
         fs::write(&cache_path, content)
             .with_context(|| format!("Failed to write cache file: {}", cache_path.display()))?;
@@ -91,6 +97,7 @@ impl ProjectCache {
     ///
     /// Retorna `true` se o cache foi modificado.
     /// Retorna `false` com `dir_mtimes` vazio (cache antigo) — chamador deve fazer rescan completo.
+    #[allow(clippy::type_complexity)]
     pub fn validate_and_update(
         &mut self,
         scan_fn: &dyn Fn(&Path) -> Result<(Vec<PathBuf>, HashMap<PathBuf, u64>)>,
@@ -154,3 +161,108 @@ impl ProjectCache {
         now_secs().saturating_sub(self.last_updated)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+    use tempfile::tempdir;
+
+    #[test]
+    fn should_return_empty_when_input_is_empty() {
+        let result = minimal_roots(&[]);
+        assert!(result.is_empty());
+    }
+
+    #[test]
+    fn should_return_single_dir_as_root() {
+        let dirs = vec![PathBuf::from("/home/user/projects")];
+        let result = minimal_roots(&dirs);
+        assert_eq!(result, dirs);
+    }
+
+    #[test]
+    fn should_exclude_nested_dirs_when_parent_is_present() {
+        let dirs = vec![
+            PathBuf::from("/home/user"),
+            PathBuf::from("/home/user/projects"),
+        ];
+        let result = minimal_roots(&dirs);
+        assert_eq!(result.len(), 1);
+        assert!(result.contains(&PathBuf::from("/home/user")));
+    }
+
+    #[test]
+    fn should_keep_sibling_dirs_that_are_not_nested() {
+        let dirs = vec![
+            PathBuf::from("/home/user/projects"),
+            PathBuf::from("/home/user/work"),
+        ];
+        let result = minimal_roots(&dirs);
+        assert_eq!(result.len(), 2);
+    }
+
+    #[test]
+    fn should_remove_stale_projects_when_git_dir_missing() {
+        let dir = tempdir().unwrap();
+        let project = dir.path().join("myproject");
+        fs::create_dir_all(project.join(".git")).unwrap();
+
+        let mut cache = ProjectCache::new(vec![project.clone()], HashMap::new());
+        assert_eq!(cache.projects.len(), 1);
+
+        fs::remove_dir_all(project.join(".git")).unwrap();
+
+        let result = cache.validate_and_update(&|_| Ok((vec![], HashMap::new())));
+        assert_eq!(result.unwrap(), true);
+        assert!(cache.projects.is_empty());
+    }
+
+    #[test]
+    fn should_return_false_when_nothing_changed() {
+        let dir = tempdir().unwrap();
+        let actual_mtime = fs::metadata(dir.path())
+            .unwrap()
+            .modified()
+            .unwrap()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_secs();
+
+        let mut dir_mtimes = HashMap::new();
+        dir_mtimes.insert(dir.path().to_path_buf(), actual_mtime);
+        let mut cache = ProjectCache::new(vec![], dir_mtimes);
+
+        let result = cache.validate_and_update(&|_| Ok((vec![], HashMap::new())));
+        assert_eq!(result.unwrap(), false);
+    }
+
+    #[test]
+    fn should_rescan_dirs_when_mtime_changed() {
+        let dir = tempdir().unwrap();
+        let tracked = dir.path().to_path_buf();
+
+        // Store mtime 0 — guaranteed to differ from the actual mtime
+        let mut dir_mtimes = HashMap::new();
+        dir_mtimes.insert(tracked, 0u64);
+        let mut cache = ProjectCache::new(vec![], dir_mtimes);
+
+        let new_project = dir.path().join("discovered");
+        let scan_called = std::cell::Cell::new(false);
+        let result = cache.validate_and_update(&|_root| {
+            scan_called.set(true);
+            Ok((vec![new_project.clone()], HashMap::new()))
+        });
+
+        assert_eq!(result.unwrap(), true);
+        assert!(scan_called.get());
+        assert!(cache.projects.contains(&new_project));
+    }
+
+    #[test]
+    fn should_return_false_when_dir_mtimes_empty() {
+        let mut cache = ProjectCache::new(vec![], HashMap::new());
+        let result = cache.validate_and_update(&|_| Ok((vec![], HashMap::new())));
+        assert_eq!(result.unwrap(), false);
+    }
+}

src/config.rs

@@ -78,18 +78,24 @@ impl Config {
         let config_path = Self::config_path()?;
 
         if !config_path.exists() {
-            let config_dir = config_path.parent()
+            let config_dir = config_path
+                .parent()
                 .context("Could not get parent directory")?;
 
-            fs::create_dir_all(config_dir)
-                .with_context(|| format!("Failed to create config directory: {}", config_dir.display()))?;
+            fs::create_dir_all(config_dir).with_context(|| {
+                format!(
+                    "Failed to create config directory: {}",
+                    config_dir.display()
+                )
+            })?;
 
             let default_config = Self::default_config();
             let toml_string = toml::to_string_pretty(&default_config)
                 .context("Failed to serialize default config")?;
 
-            fs::write(&config_path, toml_string)
-                .with_context(|| format!("Failed to write config file: {}", config_path.display()))?;
+            fs::write(&config_path, toml_string).with_context(|| {
+                format!("Failed to write config file: {}", config_path.display())
+            })?;
 
             eprintln!("Created default config at: {}", config_path.display());
         }
@@ -112,5 +118,39 @@ impl Config {
             default_session: default_session_config(),
         }
     }
-
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn should_use_defaults_when_optional_fields_missing() {
+        let toml_str = r#"paths = ["/home/user/projects"]"#;
+        let config: Config = toml::from_str(toml_str).unwrap();
+        assert_eq!(config.max_depth, 5);
+        assert!(config.cache_enabled);
+        assert_eq!(config.cache_ttl_hours, 24);
+    }
+
+    #[test]
+    fn should_parse_full_config_correctly() {
+        let toml_str = r#"
+            paths = ["/foo", "/bar"]
+            max_depth = 3
+            cache_enabled = false
+            cache_ttl_hours = 12
+        "#;
+        let config: Config = toml::from_str(toml_str).unwrap();
+        assert_eq!(config.paths, vec!["/foo", "/bar"]);
+        assert_eq!(config.max_depth, 3);
+        assert!(!config.cache_enabled);
+        assert_eq!(config.cache_ttl_hours, 12);
+    }
+
+    #[test]
+    fn should_reject_invalid_toml() {
+        let result: Result<Config, _> = toml::from_str("not valid toml ]][[");
+        assert!(result.is_err());
+    }
 }

src/session.rs

@@ -30,15 +30,16 @@ impl SessionConfig {
         let content = fs::read_to_string(&config_path)
             .with_context(|| format!("Failed to read session config: {}", config_path.display()))?;
 
-        let config: SessionConfig = toml::from_str(&content)
-            .with_context(|| format!("Failed to parse session config: {}", config_path.display()))?;
+        let config: SessionConfig = toml::from_str(&content).with_context(|| {
+            format!("Failed to parse session config: {}", config_path.display())
+        })?;
 
         Ok(Some(config))
     }
 }
 
 pub struct TmuxSession {
-    session_name: String,
+    pub(crate) session_name: String,
     project_path: String,
     base_index: usize,
 }
@@ -67,12 +68,12 @@ impl TmuxSession {
             .args(["show-options", "-gv", "base-index"])
             .output();
 
-        if let Ok(output) = output {
-            if output.status.success() {
-                let index_str = String::from_utf8_lossy(&output.stdout);
-                if let Ok(index) = index_str.trim().parse::<usize>() {
-                    return index;
-                }
+        if let Ok(output) = output
+            && output.status.success()
+        {
+            let index_str = String::from_utf8_lossy(&output.stdout);
+            if let Ok(index) = index_str.trim().parse::<usize>() {
+                return index;
             }
         }
 
@@ -206,7 +207,11 @@ impl TmuxSession {
 
         // Select the first window
         Command::new("tmux")
-            .args(["select-window", "-t", &format!("{}:{}", self.session_name, self.base_index)])
+            .args([
+                "select-window",
+                "-t",
+                &format!("{}:{}", self.session_name, self.base_index),
+            ])
             .status()
             .context("Failed to select first window")?;
 
@@ -221,13 +226,7 @@ impl TmuxSession {
             if pane_index > 0 {
                 // Create new pane by splitting
                 Command::new("tmux")
-                    .args([
-                        "split-window",
-                        "-t",
-                        &target,
-                        "-c",
-                        &self.project_path,
-                    ])
+                    .args(["split-window", "-t", &target, "-c", &self.project_path])
                     .status()
                     .context("Failed to split pane")?;
             }
@@ -236,13 +235,7 @@ impl TmuxSession {
             if !command.is_empty() {
                 let pane_target = format!("{}:{}.{}", self.session_name, window_index, pane_index);
                 Command::new("tmux")
-                    .args([
-                        "send-keys",
-                        "-t",
-                        &pane_target,
-                        command,
-                        "Enter",
-                    ])
+                    .args(["send-keys", "-t", &pane_target, command, "Enter"])
                     .status()
                     .context("Failed to send keys to pane")?;
             }
@@ -265,3 +258,52 @@ impl TmuxSession {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::Path;
+
+    #[test]
+    fn should_replace_dots_with_underscores_in_session_name() {
+        let session = TmuxSession::new(Path::new("/home/user/my.project"));
+        assert_eq!(session.session_name, "my_project");
+    }
+
+    #[test]
+    fn should_replace_spaces_with_dashes_in_session_name() {
+        let session = TmuxSession::new(Path::new("/home/user/my project"));
+        assert_eq!(session.session_name, "my-project");
+    }
+
+    #[test]
+    fn should_use_project_fallback_when_path_has_no_filename() {
+        let session = TmuxSession::new(Path::new("/"));
+        assert_eq!(session.session_name, "project");
+    }
+
+    #[test]
+    fn should_parse_window_from_toml() {
+        let toml_str = r#"
+            [[windows]]
+            name = "editor"
+            panes = ["nvim ."]
+        "#;
+        let config: SessionConfig = toml::from_str(toml_str).unwrap();
+        assert_eq!(config.windows[0].name, "editor");
+        assert_eq!(config.windows[0].panes, vec!["nvim ."]);
+    }
+
+    #[test]
+    fn should_parse_session_config_with_layout() {
+        let toml_str = r#"
+            [[windows]]
+            name = "main"
+            layout = "tiled"
+            panes = ["vim", "bash"]
+        "#;
+        let config: SessionConfig = toml::from_str(toml_str).unwrap();
+        assert_eq!(config.windows[0].layout, Some("tiled".to_string()));
+        assert_eq!(config.windows[0].panes.len(), 2);
+    }
+}