Fix off-by-one bug in Event serializer (#191)

Fixes #189

Added breaking tests for both V03 and V10 to confirm bug and changed
the logic slightly to clarify intent

Signed-off-by: Jim Crossley <jim@crossleys.org>

Cargo.toml

@@ -69,6 +69,7 @@ rstest = "0.6"
 claim = "0.3.1"
 version-sync = "0.9.2"
 serde_yaml = "0.8"
+rmp-serde = "1"
 
 # runtime dev-deps
 actix-rt = { version = "^2" }

src/event/message.rs

@@ -199,6 +199,13 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn message_v03_msgpack() {
+        let buff = rmp_serde::to_vec(&fixtures::v03::full_json_data()).unwrap();
+        let event = rmp_serde::from_slice::<Event>(buff.as_slice()).unwrap();
+        assert_eq!(event, fixtures::v03::full_json_data(),);
+    }
+
     #[test]
     fn message_v10_roundtrip_structured() -> Result<()> {
         assert_eq!(
@@ -231,4 +238,11 @@ mod tests {
         );
         Ok(())
     }
+
+    #[test]
+    fn message_v10_msgpack() {
+        let buff = rmp_serde::to_vec(&fixtures::v10::full_json_data()).unwrap();
+        let event = rmp_serde::from_slice::<Event>(buff.as_slice()).unwrap();
+        assert_eq!(event, fixtures::v10::full_json_data(),);
+    }
 }

src/event/v03/format.rs

@@ -68,16 +68,19 @@ impl<S: serde::Serializer> crate::event::format::EventFormatSerializer<S, Attrib
         extensions: &HashMap<String, ExtensionValue>,
         serializer: S,
     ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> {
-        let num =
-            3 + if attributes.datacontenttype.is_some() {
-                1
-            } else {
-                0
-            } + if attributes.schemaurl.is_some() { 1 } else { 0 }
-                + if attributes.subject.is_some() { 1 } else { 0 }
-                + if attributes.time.is_some() { 1 } else { 0 }
-                + if data.is_some() { 1 } else { 0 }
+        let num = 4
+            + [
+                attributes.datacontenttype.is_some(),
+                attributes.schemaurl.is_some(),
+                attributes.subject.is_some(),
+                attributes.time.is_some(),
+                data.is_some(),
+            ]
+            .iter()
+            .filter(|&b| *b)
+            .count()
             + extensions.len();
+
         let mut state = serializer.serialize_map(Some(num))?;
         state.serialize_entry("specversion", "0.3")?;
         state.serialize_entry("id", &attributes.id)?;

src/event/v10/format.rs

@@ -69,19 +69,19 @@ impl<S: serde::Serializer> crate::event::format::EventFormatSerializer<S, Attrib
         extensions: &HashMap<String, ExtensionValue>,
         serializer: S,
     ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error> {
-        let num =
-            3 + if attributes.datacontenttype.is_some() {
-                1
-            } else {
-                0
-            } + if attributes.dataschema.is_some() {
-                1
-            } else {
-                0
-            } + if attributes.subject.is_some() { 1 } else { 0 }
-                + if attributes.time.is_some() { 1 } else { 0 }
-                + if data.is_some() { 1 } else { 0 }
+        let num = 4
+            + [
+                attributes.datacontenttype.is_some(),
+                attributes.dataschema.is_some(),
+                attributes.subject.is_some(),
+                attributes.time.is_some(),
+                data.is_some(),
+            ]
+            .iter()
+            .filter(|&b| *b)
+            .count()
             + extensions.len();
+
         let mut state = serializer.serialize_map(Some(num))?;
         state.serialize_entry("specversion", "1.0")?;
         state.serialize_entry("id", &attributes.id)?;