internal/worker: communicate enqueue details to users

This is intended to improve the usability of the analysis pipeline.

Change-Id: Ic13d433acb06f34ee535576d5ea902b397838445
Reviewed-on: https://go-review.googlesource.com/c/pkgsite-metrics/+/492740
Run-TryBot: Zvonimir Pavlinovic <zpavlinovic@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
diff --git a/internal/worker/analysis.go b/internal/worker/analysis.go
index 820ba48..bb7b3d1 100644
--- a/internal/worker/analysis.go
+++ b/internal/worker/analysis.go
@@ -302,8 +302,11 @@
 		return err
 	}
 	tasks := createAnalysisQueueTasks(params, mods)
-	return enqueueTasks(ctx, tasks, s.queue,
+	err = enqueueTasks(ctx, tasks, s.queue,
 		&queue.Options{Namespace: "analysis", TaskNameSuffix: params.Suffix})
+	// Communicate enqueue status for better usability.
+	fmt.Fprintf(w, "enqueued %d analysis tasks with err=%v", len(tasks), err)
+	return err
 }
 
 func createAnalysisQueueTasks(params *analysis.EnqueueParams, mods []scan.ModuleSpec) []queue.Task {