fix: Propogate errors in task worker and don't return (#7357)

Signed-off-by: Simon Behar <simbeh7@gmail.com>

workflow/executor/agent.go

@@ -124,7 +124,11 @@ func (ae *AgentExecutor) taskWorker(ctx context.Context, taskQueue chan task, re
 		result, err := ae.processTask(ctx, tmpl)
 		if err != nil {
 			log.WithError(err).Error("Error in agent task")
-			return
+			result = &wfv1.NodeResult{
+				Phase:   wfv1.NodeError,
+				Message: fmt.Sprintf("error processing task: %s", err),
+			}
+			// Do not return or continue here, the "errored" result still needs to be propagated to the responseQueue below
 		}
 
 		log.WithField("phase", result.Phase).

workflow/executor/agent_test.go

@@ -0,0 +1,33 @@
+package executor
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/argoproj/argo-workflows/v3/pkg/apis/workflow/v1alpha1"
+)
+
+func TestUnsupportedTemplateTaskWorker(t *testing.T) {
+	ae := &AgentExecutor{
+		consideredTasks: map[string]bool{},
+	}
+	taskQueue := make(chan task)
+	defer close(taskQueue)
+	responseQueue := make(chan response)
+	defer close(responseQueue)
+	go ae.taskWorker(context.Background(), taskQueue, responseQueue)
+
+	taskQueue <- task{
+		NodeId: "a",
+		// This template type is not supported
+		Template: v1alpha1.Template{
+			DAG: &v1alpha1.DAGTemplate{},
+		},
+	}
+
+	response := <-responseQueue
+	assert.Equal(t, v1alpha1.NodeError, response.Result.Phase)
+	assert.Contains(t, response.Result.Message, "agent cannot execute: unknown task type")
+}