Update backend_api to account for possibly null resource vector

crates/rdsys-backend-api/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "rdsys_backend"
 authors = ["Cecylia Bocovich <cohosh@torproject.org>"]
-version = "0.1.0"
+version = "0.2.0"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

crates/rdsys-backend-api/src/proto.rs

@@ -54,9 +54,9 @@ impl Resource {
 /// A ResourceDiff holds information about new, changed, or pruned resources
 #[derive(Deserialize, PartialEq, Eq, Debug)]
 pub struct ResourceDiff {
-    pub new: Option<HashMap<String, Vec<Resource>>>,
-    pub changed: Option<HashMap<String, Vec<Resource>>>,
-    pub gone: Option<HashMap<String, Vec<Resource>>>,
+    pub new: Option<HashMap<String, Option<Vec<Resource>>>>,
+    pub changed: Option<HashMap<String, Option<Vec<Resource>>>>,
+    pub gone: Option<HashMap<String, Option<Vec<Resource>>>>,
     pub full_update: bool,
 }
 
@@ -201,7 +201,9 @@ mod tests {
         assert_eq!(diff.gone, None);
         assert_eq!(diff.full_update, true);
         if let Some(new) = diff.new {
-            assert_eq!(new["obfs2"][0].r#type, "obfs2");
+            if let Some(obfs2) = &new["obfs2"] {
+                assert_eq!(obfs2[0].r#type, "obfs2");
+            }
         }
     }
 
@@ -236,4 +238,23 @@ mod tests {
         };
         assert_eq!(diff, empty_diff);
     }
+
+    #[test]
+    fn deserialize_empty_hashmap() {
+        let data = r#"
+            {
+                "new": {
+                    "obfs4": null,
+                    "scramblesuit": []
+                },
+                "changed": null,
+                "gone": null,
+                "full_update": true
+            }"#;
+        let diff: ResourceDiff = serde_json::from_str(data).unwrap();
+        assert_ne!(diff.new, None);
+        assert_eq!(diff.changed, None);
+        assert_eq!(diff.gone, None);
+        assert_eq!(diff.full_update, true);
+    }
 }