Add serde helpers for Unix timestamps (#1988)

sdk/typespec/typespec_client_core/src/date/mod.rs

@@ -19,6 +19,7 @@ pub use time::serde::timestamp;
 // RFC 3339 vs ISO 8601: <https://ijmacd.github.io/rfc3339-iso8601/>
 pub mod iso8601;
 pub mod rfc7231;
+pub mod unix_time;
 
 /// RFC 3339: Date and Time on the Internet: Timestamps.
 ///

sdk/typespec/typespec_client_core/src/date/unix_time.rs

@@ -0,0 +1,134 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+//! Unix timestamp serde helpers.
+use serde::{de, Deserialize, Deserializer, Serializer};
+use time::{OffsetDateTime, UtcOffset};
+
+/// Deserialize a Unix timestamp into an [`OffsetDateTime`].
+pub fn deserialize<'de, D>(deserializer: D) -> Result<OffsetDateTime, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let i = i64::deserialize(deserializer)?;
+    OffsetDateTime::from_unix_timestamp(i).map_err(de::Error::custom)
+}
+
+/// Serialize an [`OffsetDateTime`] to a Unix timestamp.
+pub fn serialize<S>(date: &OffsetDateTime, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    serializer.serialize_i64(date.to_offset(UtcOffset::UTC).unix_timestamp())
+}
+
+pub mod option {
+    use serde::{Deserialize, Deserializer, Serializer};
+    use time::{OffsetDateTime, UtcOffset};
+
+    /// Deserialize a Unix timestamp into an optional [`OffsetDateTime`].
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Option<OffsetDateTime>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let i: Option<i64> = Option::deserialize(deserializer)?;
+        i.map(|i| OffsetDateTime::from_unix_timestamp(i).map_err(serde::de::Error::custom))
+            .transpose()
+    }
+
+    /// Serialize an optional [`OffsetDateTime`] to a Unix timestamp.
+    pub fn serialize<S>(date: &Option<OffsetDateTime>, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        if let Some(date) = date {
+            serializer.serialize_i64(date.to_offset(UtcOffset::UTC).unix_timestamp())
+        } else {
+            serializer.serialize_none()
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::json::{from_json, to_json};
+    use serde::{Deserialize, Serialize};
+    use time::macros::datetime;
+
+    #[derive(Deserialize, Serialize)]
+    struct TestType {
+        #[serde(
+            default,
+            skip_serializing_if = "Option::is_none",
+            with = "crate::date::unix_time::option"
+        )]
+        optional_timestamp: Option<time::OffsetDateTime>,
+
+        #[serde(with = "crate::date::unix_time")]
+        required_timestamp: time::OffsetDateTime,
+    }
+
+    #[test]
+    fn test_deserialize_none() -> crate::Result<()> {
+        let json_body = r#"{"required_timestamp":1627904772}"#;
+        let test_type: TestType = from_json(json_body)?;
+        assert_eq!(test_type.optional_timestamp, None);
+        assert_eq!(
+            test_type.required_timestamp,
+            datetime!(2021-08-02 11:46:12 UTC)
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn test_deserialize_null() -> crate::Result<()> {
+        let json_body = r#"{"optional_timestamp":null,"required_timestamp":1627904772}"#;
+        let test_type: TestType = from_json(json_body)?;
+        assert_eq!(test_type.optional_timestamp, None);
+        assert_eq!(
+            test_type.required_timestamp,
+            datetime!(2021-08-02 11:46:12 UTC)
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn test_deserialize_some() -> crate::Result<()> {
+        let json_body = r#"{"optional_timestamp":1625136302,"required_timestamp":1627904772}"#;
+        let test_type: TestType = from_json(json_body)?;
+        assert_eq!(
+            test_type.optional_timestamp,
+            Some(datetime!(2021-07-01 10:45:02 UTC))
+        );
+        assert_eq!(
+            test_type.required_timestamp,
+            datetime!(2021-08-02 11:46:12 UTC)
+        );
+        Ok(())
+    }
+
+    #[test]
+    fn test_serialize_none() -> crate::Result<()> {
+        let test_type = TestType {
+            optional_timestamp: None,
+            required_timestamp: datetime!(2021-08-02 11:46:12 UTC),
+        };
+        let json_body = to_json(&test_type)?;
+        assert_eq!(json_body, r#"{"required_timestamp":1627904772}"#);
+        Ok(())
+    }
+
+    #[test]
+    fn test_serialize_some() -> crate::Result<()> {
+        let test_type = TestType {
+            optional_timestamp: Some(datetime!(2021-07-01 10:45:02 UTC)),
+            required_timestamp: datetime!(2021-08-02 11:46:12 UTC),
+        };
+        let json_body = to_json(&test_type)?;
+        assert_eq!(
+            json_body,
+            r#"{"optional_timestamp":1625136302,"required_timestamp":1627904772}"#
+        );
+        Ok(())
+    }
+}