feat: add run result

runner_test.go

@@ -28,7 +28,8 @@ func TestBasicRun(t *testing.T) {
 		Processor: echoProcessor,
 	}
 
-	if err := script.Run(t.Context(), conf); err != nil {
+	res, err := script.Run(t.Context(), conf)
+	if err != nil {
 		t.Fatal(err)
 	}
 
@@ -37,6 +38,10 @@ func TestBasicRun(t *testing.T) {
 	if !reflect.DeepEqual(input, output) {
 		t.Errorf("incorrect output, want: %v, got: %v", input, output)
 	}
+
+	if res.Read != 1 || res.Processed != 1 || res.Written != 1 {
+		t.Fatal("incorrect process result, want all fields to equal 1")
+	}
 }
 
 type infiniteReader struct{}
@@ -60,7 +65,7 @@ func TestRunnerObeysContext(t *testing.T) {
 	ctx, cancel := context.WithTimeout(t.Context(), time.Millisecond)
 	defer cancel()
 
-	if err := script.Run(ctx, conf); err != nil {
+	if _, err := script.Run(ctx, conf); err != nil {
 		t.Fatal(err)
 	}
 }