fix(rules): include the macOS Chrome cache

CHANGELOG.md

@@ -8,6 +8,7 @@ All notable changes to Diskern are documented here. The format follows
 
 ### Fixed
 
+- Chrome caches under macOS `~/Library/Caches` now appear in scan reports
 - A relative scan root no longer hides every finding a root-anchored rule
   would have made. `diskern scan tmp` from `/var` reported nothing to
   clean; roots are resolved to absolute paths before the walk

crates/diskern-core/rules/base.json

@@ -24,7 +24,7 @@
     },
     {
       "id": "chrome-cache",
-      "patterns": ["**/google/chrome/user data/*/cache/**", "**/.cache/google-chrome/**"],
+      "patterns": ["**/google/chrome/user data/*/cache/**", "**/.cache/google-chrome/**", "**/library/caches/google/chrome/*/cache/**", "**/library/caches/google/chrome/*/code cache/**"],
       "category": "browser_cache",
       "verdict": "safe",
       "description": "Chrome browser cache. Fully regenerated on next use; no effect on installed applications or saved data."

crates/diskern-core/src/rules.rs

@@ -370,6 +370,30 @@ mod tests {
         }
     }
 
+    #[test]
+    fn chrome_cache_is_safe_to_remove_on_each_platform() {
+        let db = RulesDb::embedded();
+        for path in [
+            "/home/u/.cache/google-chrome/Default/Cache/data_0",
+            "C:\\Users\\x\\AppData\\Local\\Google\\Chrome\\User Data\\Default\\Cache\\data_0",
+            "/Users/x/Library/Caches/Google/Chrome/Default/Cache/data_0",
+            "/Users/x/Library/Caches/Google/Chrome/Default/Code Cache/js/index",
+        ] {
+            let (cat, verdict, rule) = db.classify(std::path::Path::new(path));
+            assert_eq!(cat, Category::BrowserCache, "{path} matched {rule:?}");
+            assert_eq!(verdict, Verdict::Safe, "{path} matched {rule:?}");
+        }
+    }
+
+    #[test]
+    fn chrome_profile_data_is_not_safe_to_remove() {
+        let db = RulesDb::embedded();
+        let path = "/Users/x/Library/Application Support/Google/Chrome/Default/History";
+        let (cat, verdict, rule) = db.classify(std::path::Path::new(path));
+        assert_eq!(cat, Category::Unknown, "{path} matched {rule:?}");
+        assert_ne!(verdict, Verdict::Safe, "{path} matched {rule:?}");
+    }
+
     /// Issue #40. `/mozilla/firefox/profiles` covered the whole profile
     /// directory, so bookmarks, history, logins and cookies were listed
     /// under "Safe to remove" and `quarantine_finding` accepted them.

docs/RULES.md

@@ -10,7 +10,7 @@ time from [`crates/diskern-core/rules/base.json`](../crates/diskern-core/rules/b
 ```json
 {
   "id": "chrome-cache",
-  "patterns": ["**/google/chrome/user data/*/cache/**", "**/.cache/google-chrome/**"],
+  "patterns": ["**/google/chrome/user data/*/cache/**", "**/.cache/google-chrome/**", "**/library/caches/google/chrome/*/cache/**", "**/library/caches/google/chrome/*/code cache/**"],
   "category": "browser_cache",
   "verdict": "safe",
   "description": "Chrome browser cache. Fully regenerated on next use."