test(hstr): Add tests (#10043)

Author: kdy1

crates/hstr/src/dynamic.rs

@@ -20,7 +20,7 @@ pub(crate) struct Metadata {
 }
 
 #[derive(Clone)]
-pub(crate) struct Item(ThinArc<HeaderWithLength<Metadata>, u8>);
+pub(crate) struct Item(pub ThinArc<HeaderWithLength<Metadata>, u8>);
 
 impl Deref for Item {
     type Target = <ThinArc<HeaderWithLength<Metadata>, u8> as Deref>::Target;

crates/hstr/src/lib.rs

@@ -273,6 +273,20 @@ impl Atom {
     }
 }
 
+#[cfg(test)]
+impl Atom {
+    pub(crate) fn ref_count(&self) -> usize {
+        match self.tag() {
+            DYNAMIC_TAG => {
+                let ptr = unsafe { crate::dynamic::deref_from(self.unsafe_data) };
+
+                triomphe::ThinArc::strong_count(&ptr.0)
+            }
+            _ => 1,
+        }
+    }
+}
+
 impl PartialEq for Atom {
     #[inline(never)]
     fn eq(&self, other: &Self) -> bool {

crates/hstr/src/tests.rs

@@ -55,3 +55,30 @@ fn store_multiple() {
     assert_eq!(a1.get_hash(), a2.get_hash(), "Same string should be equal");
     assert_eq!(a1, a2, "Same string should be equal");
 }
+
+#[test]
+fn store_ref_count() {
+    let (store, atoms) = store_with_atoms(vec!["Hello, world!!!!"]);
+
+    assert_eq!(atoms[0].ref_count(), 2);
+    drop(store);
+    assert_eq!(atoms[0].ref_count(), 1);
+}
+
+#[test]
+fn store_ref_count_dynamic() {
+    let (store, atoms) = store_with_atoms(vec!["Hello, world!!!!"]);
+
+    let a1 = atoms[0].clone();
+    let a2 = atoms[0].clone();
+
+    assert_eq!(atoms[0].ref_count(), 4);
+    drop(store);
+    assert_eq!(atoms[0].ref_count(), 3);
+
+    drop(a1);
+    assert_eq!(atoms[0].ref_count(), 2);
+
+    drop(a2);
+    assert_eq!(atoms[0].ref_count(), 1);
+}