1 files changed, 65 insertions, 0 deletions
diff --git a/third_party/rust/hashbrown/tests/serde.rs b/third_party/rust/hashbrown/tests/serde.rs
new file mode 100644
index 0000000000..570bf70da9
--- /dev/null
+++ b/third_party/rust/hashbrown/tests/serde.rs
@@ -0,0 +1,65 @@
+#![cfg(feature = "serde")]
+
+use core::hash::BuildHasherDefault;
+use hashbrown::{HashMap, HashSet};
+use rustc_hash::FxHasher;
+use serde_test::{assert_tokens, Token};
+
+// We use FxHash for this test because we rely on the ordering
+type FxHashMap<K, V> = HashMap<K, V, BuildHasherDefault<FxHasher>>;
+type FxHashSet<T> = HashSet<T, BuildHasherDefault<FxHasher>>;
+
+#[test]
+fn map_serde_tokens_empty() {
+    let map = FxHashMap::<char, u32>::default();
+
+    assert_tokens(&map, &[Token::Map { len: Some(0) }, Token::MapEnd]);
+}
+
+#[test]
+fn map_serde_tokens() {
+    let mut map = FxHashMap::default();
+    map.insert('b', 20);
+    map.insert('a', 10);
+    map.insert('c', 30);
+
+    assert_tokens(
+        &map,
+        &[
+            Token::Map { len: Some(3) },
+            Token::Char('a'),
+            Token::I32(10),
+            Token::Char('b'),
+            Token::I32(20),
+            Token::Char('c'),
+            Token::I32(30),
+            Token::MapEnd,
+        ],
+    );
+}
+
+#[test]
+fn set_serde_tokens_empty() {
+    let set = FxHashSet::<u32>::default();
+
+    assert_tokens(&set, &[Token::Seq { len: Some(0) }, Token::SeqEnd]);
+}
+
+#[test]
+fn set_serde_tokens() {
+    let mut set = FxHashSet::default();
+    set.insert(20);
+    set.insert(10);
+    set.insert(30);
+
+    assert_tokens(
+        &set,
+        &[
+            Token::Seq { len: Some(3) },
+            Token::I32(20),
+            Token::I32(10),
+            Token::I32(30),
+            Token::SeqEnd,
+        ],
+    );
+}