4 files changed, 68 insertions, 2 deletions
diff --git a/third_party/rust/hashbrown/tests/equivalent_trait.rs b/third_party/rust/hashbrown/tests/equivalent_trait.rs
new file mode 100644
index 0000000000..713dddd53c
--- /dev/null
+++ b/third_party/rust/hashbrown/tests/equivalent_trait.rs
@@ -0,0 +1,53 @@
+use hashbrown::Equivalent;
+use hashbrown::HashMap;
+
+use std::hash::Hash;
+
+#[derive(Debug, Hash)]
+pub struct Pair<A, B>(pub A, pub B);
+
+impl<A, B, C, D> PartialEq<(A, B)> for Pair<C, D>
+where
+    C: PartialEq<A>,
+    D: PartialEq<B>,
+{
+    fn eq(&self, rhs: &(A, B)) -> bool {
+        self.0 == rhs.0 && self.1 == rhs.1
+    }
+}
+
+impl<A, B, X> Equivalent<X> for Pair<A, B>
+where
+    Pair<A, B>: PartialEq<X>,
+    A: Hash + Eq,
+    B: Hash + Eq,
+{
+    fn equivalent(&self, other: &X) -> bool {
+        *self == *other
+    }
+}
+
+#[test]
+fn test_lookup() {
+    let s = String::from;
+    let mut map = HashMap::new();
+    map.insert((s("a"), s("b")), 1);
+    map.insert((s("a"), s("x")), 2);
+
+    assert!(map.contains_key(&Pair("a", "b")));
+    assert!(!map.contains_key(&Pair("b", "a")));
+}
+
+#[test]
+fn test_string_str() {
+    let s = String::from;
+    let mut map = HashMap::new();
+    map.insert(s("a"), 1);
+    map.insert(s("b"), 2);
+    map.insert(s("x"), 3);
+    map.insert(s("y"), 4);
+
+    assert!(map.contains_key("a"));
+    assert!(!map.contains_key("z"));
+    assert_eq!(map.remove("b"), Some(2));
+}
diff --git a/third_party/rust/hashbrown/tests/raw.rs b/third_party/rust/hashbrown/tests/raw.rs
new file mode 100644
index 0000000000..858836e63b
--- /dev/null
+++ b/third_party/rust/hashbrown/tests/raw.rs
@@ -0,0 +1,11 @@
+#![cfg(feature = "raw")]
+
+use hashbrown::raw::RawTable;
+use std::mem;
+
+#[test]
+fn test_allocation_info() {
+    assert_eq!(RawTable::<()>::new().allocation_info().1.size(), 0);
+    assert_eq!(RawTable::<u32>::new().allocation_info().1.size(), 0);
+    assert!(RawTable::<u32>::with_capacity(1).allocation_info().1.size() > mem::size_of::<u32>());
+}
diff --git a/third_party/rust/hashbrown/tests/rayon.rs b/third_party/rust/hashbrown/tests/rayon.rs
index 8c603c5c41..d55e5a9804 100644
--- a/third_party/rust/hashbrown/tests/rayon.rs
+++ b/third_party/rust/hashbrown/tests/rayon.rs
@@ -356,7 +356,9 @@ fn set_seq_par_equivalence_into_iter_empty() {
     let vec_seq = SET_EMPTY.clone().into_iter().collect::<Vec<_>>();
     let vec_par = SET_EMPTY.clone().into_par_iter().collect::<Vec<_>>();
 
-    assert_eq3!(vec_seq, vec_par, []);
+    // Work around type inference failure introduced by rend dev-dependency.
+    let empty: [char; 0] = [];
+    assert_eq3!(vec_seq, vec_par, empty);
 }
 
 #[test]
diff --git a/third_party/rust/hashbrown/tests/set.rs b/third_party/rust/hashbrown/tests/set.rs
index 5ae1ec98ec..86ec964766 100644
--- a/third_party/rust/hashbrown/tests/set.rs
+++ b/third_party/rust/hashbrown/tests/set.rs
@@ -27,7 +27,7 @@ fn test_hashset_insert_remove() {
             assert_eq!(m.insert(x.clone()), true);
         }
         for (i, x) in tx.iter().enumerate() {
-            println!("removing {} {:?}", i, x);
+            println!("removing {i} {x:?}");
             assert_eq!(m.remove(x), true);
         }
     }