1 files changed, 60 insertions, 0 deletions
diff --git a/third_party/rust/unic-langid-impl/src/serde.rs b/third_party/rust/unic-langid-impl/src/serde.rs
new file mode 100644
index 0000000000..faac0b0288
--- /dev/null
+++ b/third_party/rust/unic-langid-impl/src/serde.rs
@@ -0,0 +1,60 @@
+use crate::LanguageIdentifier;
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
+
+impl Serialize for LanguageIdentifier {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for LanguageIdentifier {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct LanguageIdentifierVisitor;
+
+        impl<'de> serde::de::Visitor<'de> for LanguageIdentifierVisitor {
+            type Value = LanguageIdentifier;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                write!(formatter, "A valid Unicode Language Identifier")
+            }
+
+            fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
+            where
+                E: serde::de::Error,
+            {
+                s.parse::<LanguageIdentifier>()
+                    .map_err(serde::de::Error::custom)
+            }
+        }
+
+        deserializer.deserialize_string(LanguageIdentifierVisitor)
+    }
+}
+
+#[test]
+fn serialize() -> Result<(), Box<dyn std::error::Error>> {
+    let fr = serde_json::json!("fr".parse::<LanguageIdentifier>()?);
+    let en = serde_json::json!("en-US".parse::<LanguageIdentifier>()?);
+
+    assert_eq!(serde_json::to_string(&fr)?, r#""fr""#);
+    assert_eq!(serde_json::to_string(&en)?, r#""en-US""#);
+
+    Ok(())
+}
+
+#[test]
+fn deserialize() -> Result<(), Box<dyn std::error::Error>> {
+    let fr = serde_json::from_str::<LanguageIdentifier>(r#""fr""#)?;
+    let en = serde_json::from_str::<LanguageIdentifier>(r#""en-US""#)?;
+
+    assert_eq!(fr, "fr".parse::<LanguageIdentifier>()?);
+    assert_eq!(en, "en-US".parse::<LanguageIdentifier>()?);
+
+    Ok(())
+}