feat: improve legacy metadata and admin compatibility (#2202)

crates/policy/src/policy/doc.rs

@@ -19,9 +19,27 @@ use super::Policy;
 
 #[derive(Serialize, Deserialize, Default, Clone)]
 pub struct PolicyDoc {
+    /// Version (omitempty), legacy: version.
+    #[serde(rename = "Version", alias = "version", default)]
     pub version: i64,
+    /// Policy, legacy: policy. Serialize as Policy.
+    #[serde(rename = "Policy", alias = "policy")]
     pub policy: Policy,
+    /// CreateDate (RFC3339), legacy: create_date. Serialize as CreateDate.
+    #[serde(
+        rename = "CreateDate",
+        alias = "create_date",
+        default,
+        with = "crate::serde_datetime::option"
+    )]
     pub create_date: Option<OffsetDateTime>,
+    /// UpdateDate (RFC3339), legacy: update_date. Serialize as UpdateDate.
+    #[serde(
+        rename = "UpdateDate",
+        alias = "update_date",
+        default,
+        with = "crate::serde_datetime::option"
+    )]
     pub update_date: Option<OffsetDateTime>,
 }
 
@@ -73,3 +91,43 @@ impl TryFrom<Vec<u8>> for PolicyDoc {
             .map_err(|_| serde_json::Error::custom("Failed to parse as PolicyDoc or Policy".to_string()))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::policy::Policy;
+
+    #[test]
+    fn test_policy_doc_timestamps_serialize_as_rfc3339() {
+        let policy = Policy::default();
+        let doc = PolicyDoc::new(policy);
+        let json = serde_json::to_string(&doc).expect("serialize");
+        // RFC3339 uses 'T' between date and time and 'Z' or offset for UTC
+        assert!(json.contains('T'), "PolicyDoc timestamps should be RFC3339 (contain 'T'); got: {}", json);
+        assert!(
+            json.contains('Z') || json.contains("+00:00"),
+            "PolicyDoc timestamps should be RFC3339 (contain 'Z' or +00:00); got: {}",
+            json
+        );
+    }
+
+    #[test]
+    fn test_policy_doc_deserialize_minio_style_rfc3339_timestamps() {
+        let minio_style = r#"{"Version":1,"Policy":{"Version":"2012-10-17","Statement":[]},"CreateDate":"2025-03-07T12:00:00Z","UpdateDate":"2025-03-07T12:00:00Z"}"#;
+        let doc: PolicyDoc = serde_json::from_str(minio_style).expect("deserialize MinIO-style JSON");
+        assert_eq!(doc.version, 1);
+        assert!(doc.create_date.is_some());
+        assert!(doc.update_date.is_some());
+    }
+
+    /// Round-trip: serialize then deserialize PolicyDoc; timestamps must match.
+    #[test]
+    fn test_policy_doc_timestamp_roundtrip() {
+        let policy = Policy::default();
+        let doc = PolicyDoc::new(policy);
+        let json = serde_json::to_string(&doc).expect("serialize");
+        let restored: PolicyDoc = serde_json::from_str(&json).expect("deserialize");
+        assert_eq!(doc.create_date, restored.create_date);
+        assert_eq!(doc.update_date, restored.update_date);
+    }
+}

crates/policy/src/policy/policy.rs

@@ -55,9 +55,9 @@ impl Args<'_> {
 pub struct Policy {
     #[serde(default, rename = "ID")]
     pub id: ID,
-    #[serde(rename = "Version")]
+    #[serde(default, rename = "Version")]
     pub version: String,
-    #[serde(rename = "Statement")]
+    #[serde(default, rename = "Statement")]
     pub statements: Vec<Statement>,
 }
 
@@ -1084,6 +1084,14 @@ mod test {
         );
     }
 
+    #[test]
+    fn test_parse_empty_policy_object_as_implied_policy() {
+        let policy = Policy::parse_config(b"{}").expect("empty JSON object should parse");
+
+        assert!(policy.version.is_empty());
+        assert!(policy.statements.is_empty());
+    }
+
     #[test]
     fn test_statement_with_both_action_and_notaction_is_invalid() {
         // Test: A statement with both Action and NotAction returns BothActionAndNotAction error