buffer blocks while no changes underlying, test buffer

src/device/input/input_exported_test.go

@@ -17,13 +17,33 @@ func TestNew(t *testing.T) {
 	}
 }
 
+func TestNewBuffered(t *testing.T) {
+	os.Setenv("INPUT_BUFFERED", "true")
+	t.Cleanup(func() {
+		os.Unsetenv("INPUT_BUFFERED")
+	})
+
+	r := input.New()
+	for i := 0; i < 15; i++ {
+		batch := r.Read()
+		for j := range batch {
+			t.Logf("[%d][%d] %c|%v", i, j, batch[j].Char, batch[j].Down)
+		}
+	}
+}
+
 func TestNewRandomWeightFile(t *testing.T) {
 	d := t.TempDir()
 	p := path.Join(d, "f")
 	if err := os.WriteFile(p, []byte(`{"a":1}`), os.ModePerm); err != nil {
 		t.Fatal(err)
 	}
+
 	os.Setenv("INPUT_RANDOM_WEIGHT_FILE", p)
+	t.Cleanup(func() {
+		os.Unsetenv("INPUT_RANDOM_WEIGHT_FILE")
+	})
+
 	r := input.New()
 	for i := 0; i < 15; i++ {
 		batch := r.Read()