fix(contexts): Overwrite non-string context types

CHANGELOG.md

@@ -11,6 +11,8 @@
 - Preserve user specified event values in Unreal crash reports. ([#4882](https://github.com/getsentry/relay/pull/4882))
 - OS name parsing of Unreal crash reports. ([#4854](https://github.com/getsentry/relay/pull/4854))
 - Do not overwrite geo information if already set. ([#4888](https://github.com/getsentry/relay/pull/4888))
+- The `type` fields of contexts are now enforced to be strings. Non-string values are replaced with the
+  context's key. ([#4932](https://github.com/getsentry/relay/pull/4932))
 
 **Internal**:
 

relay-event-schema/src/protocol/contexts/mod.rs

@@ -274,7 +274,7 @@ impl FromValue for Contexts {
             for (key, value) in items.iter_mut() {
                 if let Annotated(Some(Value::Object(items)), _) = value {
                     // Set the `"type"` if it's empty and overwrite it if it's an empty object or array.
-                    if value_is_empty(items.get("type")) {
+                    if !is_valid_context_type(items.get("type")) {
                         items.insert(
                             "type".to_owned(),
                             Annotated::new(Value::String(key.to_string())),
@@ -287,17 +287,10 @@ impl FromValue for Contexts {
     }
 }
 
-/// Returns `true` if `value` is `None`, empty object, or an empty array.
-fn value_is_empty(value: Option<&Annotated<Value>>) -> bool {
-    let Some(value) = value.and_then(|v| v.value()) else {
-        return true;
-    };
-
-    match value {
-        Value::Array(values) => values.is_empty(),
-        Value::Object(values) => values.is_empty(),
-        _ => false,
-    }
+/// Returns `true` if `value` is a non-empty string, which is the only valid value
+/// for the `"type"` field of a context.
+fn is_valid_context_type(value: Option<&Annotated<Value>>) -> bool {
+    matches!(value.and_then(|v| v.value()), Some(Value::String(s)) if !s.is_empty())
 }
 
 /// A well-known context in the [`Contexts`] interface.
@@ -371,14 +364,28 @@ mod tests {
     }
 
     #[test]
-    fn test_context_empty_type_deserialize() {
-        let json = r#"{"os":{"name":"Linux","type":{}},"runtime":{"name":"rustc","type":[]}}"#;
+    fn test_context_invalid_type_deserialize() {
+        let json = r#"{
+            "monitor":{"name":"Foobar","type":17},
+            "os":{"name":"Linux","type":{}},
+            "profile":{"profile_id":"52df9022835246eeb317dbd739ccd059","type":""},
+            "runtime":{"name":"rustc","type":["invalid"]}
+        }"#;
 
         let mut map = Contexts::new();
+        map.add(MonitorContext(
+            [("name".to_owned(), Value::String("Foobar".to_owned()).into())]
+                .into_iter()
+                .collect(),
+        ));
         map.add(OsContext {
             name: Annotated::new("Linux".to_owned()),
             ..Default::default()
         });
+        map.add(ProfileContext {
+            profile_id: Annotated::new("52df9022835246eeb317dbd739ccd059".parse().unwrap()),
+            ..Default::default()
+        });
         map.add(RuntimeContext {
             name: Annotated::new("rustc".to_owned()),
             ..Default::default()