fix: tighten Poetry cache path matching (#417)

Summary:
- Match Poetry cache paths by ordered path components instead of raw
substrings.
- Preserve support for Linux/macOS cache layouts and the Windows
`pypoetry/Cache/virtualenvs` layout.
- Add tests for exact components, ordering, mixed case, substring false
positives, and invalid Poetry environment names.

Validation:
- cargo test -p pet-poetry
- cargo fmt --all
- cargo clippy --all -- -D warnings

Fixes #398

Author: karthiknadig

crates/pet-poetry/src/lib.rs

@@ -45,14 +45,11 @@ fn is_poetry_cache_environment(path: &Path) -> bool {
     // - Linux: ~/.cache/pypoetry/virtualenvs/
     // - macOS: ~/Library/Caches/pypoetry/virtualenvs/
     // - Windows: %LOCALAPPDATA%\pypoetry\Cache\virtualenvs\
-    let path_str = path.to_str().unwrap_or_default();
-
-    // Check if path contains typical Poetry cache directory structure
-    if path_str.contains("pypoetry") && path_str.contains("virtualenvs") {
+    if has_poetry_cache_components(path) {
         // Further validate by checking if the directory name matches Poetry's naming pattern
-        // Pattern: {name}-{8-char-hash}-py or just .venv
+        // Pattern: {name}-{8-char-hash}-py{version}
         if let Some(dir_name) = path.file_name().and_then(|n| n.to_str()) {
-            // Check for Poetry's hash-based naming: name-XXXXXXXX-py
+            // Check for Poetry's hash-based naming: name-XXXXXXXX-py<major>.<minor>
             // The hash is 8 characters of base64url encoding
             if POETRY_ENV_NAME_PATTERN.is_match(dir_name) {
                 return true;
@@ -63,6 +60,27 @@ fn is_poetry_cache_environment(path: &Path) -> bool {
     false
 }
 
+fn has_poetry_cache_components(path: &Path) -> bool {
+    let mut found_pypoetry = false;
+
+    for component in path.components() {
+        let Some(component) = component.as_os_str().to_str() else {
+            return false;
+        };
+
+        if component.eq_ignore_ascii_case("pypoetry") {
+            found_pypoetry = true;
+            continue;
+        }
+
+        if found_pypoetry && component.eq_ignore_ascii_case("virtualenvs") {
+            return true;
+        }
+    }
+
+    false
+}
+
 /// Check if a .venv directory is an in-project Poetry environment
 /// This is for the case when virtualenvs.in-project = true is set.
 /// We check if the parent directory has Poetry configuration files.
@@ -359,6 +377,100 @@ mod tests {
     use super::*;
     use pet_core::os_environment::EnvironmentApi;
 
+    fn path_from_components(components: &[&str]) -> PathBuf {
+        let mut path = PathBuf::new();
+        for component in components {
+            path.push(component);
+        }
+        path
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_requires_exact_cache_components() {
+        let path = path_from_components(&[
+            "home",
+            "user",
+            ".cache",
+            "pypoetry",
+            "virtualenvs",
+            "project-1a2b3c4d-py3.11",
+        ]);
+
+        assert!(is_poetry_cache_environment(&path));
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_allows_windows_cache_component() {
+        let path = path_from_components(&[
+            "Users",
+            "user",
+            "AppData",
+            "Local",
+            "pypoetry",
+            "Cache",
+            "virtualenvs",
+            "project-1a2b3c4d-py3.11",
+        ]);
+
+        assert!(is_poetry_cache_environment(&path));
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_rejects_substring_cache_components() {
+        let path = path_from_components(&[
+            "Users",
+            "pypoetry_user",
+            "virtualenvs_backup",
+            "project-1a2b3c4d-py3.11",
+        ]);
+
+        assert!(!is_poetry_cache_environment(&path));
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_requires_ordered_cache_components() {
+        let path = path_from_components(&[
+            "home",
+            "user",
+            ".cache",
+            "virtualenvs",
+            "pypoetry",
+            "project-1a2b3c4d-py3.11",
+        ]);
+
+        assert!(!is_poetry_cache_environment(&path));
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_allows_mixed_case_cache_components() {
+        let path = path_from_components(&[
+            "Users",
+            "user",
+            "AppData",
+            "Local",
+            "PyPoetry",
+            "Cache",
+            "VirtualEnvs",
+            "project-1a2b3c4d-py3.11",
+        ]);
+
+        assert!(is_poetry_cache_environment(&path));
+    }
+
+    #[test]
+    fn test_poetry_cache_environment_requires_poetry_env_name() {
+        let path = path_from_components(&[
+            "home",
+            "user",
+            ".cache",
+            "pypoetry",
+            "virtualenvs",
+            "not-a-poetry-env",
+        ]);
+
+        assert!(!is_poetry_cache_environment(&path));
+    }
+
     #[test]
     fn test_sync_search_result_from_replaces_cached_result() {
         let environment = EnvironmentApi::new();