fix: handle both 'deprecated' enum values when merging coprocessor context

.changesets/fix_caroline_rh_1292.md

@@ -0,0 +1,9 @@
+### Handle both 'deprecated' enum values when merging coprocessor context ([PR #8913](https://github.com/apollographql/router/pull/8913))
+
+A change to coprocessor context merges in Router v2.10 caused keys to be deleted when `context: true` is used as the coprocessor context selector in the router configuration file.
+
+The quick fix in the router config is to pass `context: deprecated` instead.
+
+This change brings parity when `context: true` is provided.
+
+By [@carodewig](https://github.com/carodewig) in https://github.com/apollographql/router/pull/8913

apollo-router/src/plugins/coprocessor/mod.rs

@@ -467,6 +467,15 @@ pub(super) enum ContextConf {
     NewContextConf(NewContextConf),
 }
 
+impl ContextConf {
+    fn is_deprecated(&self) -> bool {
+        match self {
+            Self::Deprecated(v) => *v,
+            Self::NewContextConf(c) => *c == NewContextConf::Deprecated,
+        }
+    }
+}
+
 impl Default for ContextConf {
     fn default() -> Self {
         Self::Deprecated(false)
@@ -564,7 +573,7 @@ pub(crate) fn update_context_from_coprocessor(
 
     for (mut key, value) in context_returned.try_into_iter()? {
         // Handle deprecated key names - convert back to actual key names
-        if let ContextConf::NewContextConf(NewContextConf::Deprecated) = context_config {
+        if context_config.is_deprecated() {
             key = context_key_from_deprecated(key);
         }
 

apollo-router/src/plugins/coprocessor/test.rs

@@ -74,6 +74,7 @@ mod tests {
 
     use super::super::*;
     use crate::assert_response_eq_ignoring_error_id;
+    use crate::context::deprecated::DEPRECATED_CLIENT_NAME;
     use crate::graphql::Response;
     use crate::json_ext::Object;
     use crate::json_ext::Value;
@@ -92,6 +93,7 @@ mod tests {
     use crate::plugins::coprocessor::supergraph::SupergraphStage;
     use crate::plugins::coprocessor::test::assert_coprocessor_operations_metrics;
     use crate::plugins::coprocessor::was_incoming_payload_valid;
+    use crate::plugins::telemetry::CLIENT_NAME;
     use crate::plugins::telemetry::config_new::conditions::SelectorOrValue;
     use crate::services::external::EXTERNALIZABLE_VERSION;
     use crate::services::external::Externalizable;
@@ -4316,6 +4318,36 @@ mod tests {
         );
     }
 
+    #[rstest::rstest]
+    fn test_update_context_from_coprocessor_handles_deprecated_key_names(
+        #[values(DEPRECATED_CLIENT_NAME, CLIENT_NAME)] target_context_key_name: &str,
+        #[values(
+            ContextConf::Deprecated(true),
+            ContextConf::NewContextConf(NewContextConf::Deprecated)
+        )]
+        context_conf: ContextConf,
+    ) {
+        use crate::Context;
+        use crate::plugins::coprocessor::update_context_from_coprocessor;
+
+        let target_context =
+            Context::from_iter([(target_context_key_name.to_string(), "v1".into())]);
+        let returned_context =
+            Context::from_iter([(DEPRECATED_CLIENT_NAME.to_string(), "v2".into())]);
+
+        update_context_from_coprocessor(&target_context, returned_context, &context_conf).unwrap();
+
+        assert_eq!(
+            target_context.get_json_value(CLIENT_NAME),
+            Some(json!("v2")),
+        );
+
+        assert!(
+            !target_context.contains_key(DEPRECATED_CLIENT_NAME),
+            "DEPRECATED_CLIENT_NAME should not be present"
+        );
+    }
+
     // Subgraph stage metrics test
     #[tokio::test]
     async fn subgraph_request_metric_incremented_when_condition_true() {