Merge pull request #2539 from dgageot/extract-stream-processor

refactor(runtime): drop unused receiver from handleStream

Author: dgageot

pkg/runtime/fallback.go

@@ -285,7 +285,7 @@ func (r *LocalRuntime) tryModelWithFallback(
 				}
 			}
 
-			res, err := r.handleStream(ctx, stream, a, agentTools, sess, m, events)
+			res, err := handleStream(ctx, stream, a, agentTools, sess, m, events)
 			if err != nil {
 				lastErr = err
 

pkg/runtime/streaming.go

@@ -34,7 +34,13 @@ type streamResult struct {
 // events (content deltas, partial tool calls, reasoning tokens) and returning
 // the aggregated streamResult. The caller is responsible for adding the
 // resulting assistant message to the session.
-func (r *LocalRuntime) handleStream(ctx context.Context, stream chat.MessageStream, a *agent.Agent, agentTools []tools.Tool, sess *session.Session, m *modelsdev.Model, events chan Event) (streamResult, error) {
+//
+// handleStream is a pure stream-aggregation routine: it does not touch
+// runtime state and can be unit-tested by feeding a mock chat.MessageStream.
+// It is intentionally a free function rather than a method on *LocalRuntime
+// so the dependency direction is explicit (the loop calls into the chunker,
+// never the reverse).
+func handleStream(ctx context.Context, stream chat.MessageStream, a *agent.Agent, agentTools []tools.Tool, sess *session.Session, m *modelsdev.Model, events chan<- Event) (streamResult, error) {
 	defer stream.Close()
 
 	var fullContent strings.Builder