From 1ee095dbddd92aff13e1a47e30f67fff8269dd03 Mon Sep 17 00:00:00 2001
From: Maarten Breddels <maartenbreddels@gmail.com>
Date: Thu, 8 Feb 2018 20:29:16 +0100
Subject: [PATCH] fix: empty lists were not serialized property, but send as
 empty ndarray

---
 ipyvolume/serialize.py |  7 +++++--
 ipyvolume/test_all.py  | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/ipyvolume/serialize.py b/ipyvolume/serialize.py
index edb515a3..43ed5197 100644
--- a/ipyvolume/serialize.py
+++ b/ipyvolume/serialize.py
@@ -154,8 +154,11 @@ def array_sequence_to_binary_or_json(ar, obj=None):
 		pass
 	if isinstance(element, string_types):
 		return array_to_json(ar)
-	if dimension == 0: # scalars are passed as is (json)
-		return element
+	if dimension == 0: # scalars are passed as is (json), empty lists as well
+		if isinstance(element, np.ndarray): # must be an empty list
+			return []
+		else:
+			return element
 	if isinstance(ar, (list, tuple, np.ndarray)): # ok, at least 1d
 		if isinstance(ar[0], (list, tuple, np.ndarray)): # ok, 2d
 			return [array_to_binary(ar[k]) for k in range(len(ar))]
diff --git a/ipyvolume/test_all.py b/ipyvolume/test_all.py
index 15864f45..9bccd0fb 100644
--- a/ipyvolume/test_all.py
+++ b/ipyvolume/test_all.py
@@ -4,6 +4,7 @@
 import ipyvolume.examples
 import ipyvolume.datasets
 import ipyvolume.utils
+import ipyvolume.serialize
 import numpy as np
 import os
 import shutil
@@ -16,6 +17,19 @@
     shutil.rmtree("tmp")
 os.makedirs("tmp")
 
+def test_serialize():
+    assert ipyvolume.serialize.array_sequence_to_binary_or_json(1) == 1
+    assert ipyvolume.serialize.array_sequence_to_binary_or_json([]) == []
+    empty_array = np.array([])
+    assert ipyvolume.serialize.array_sequence_to_binary_or_json(empty_array) == []
+    assert type(ipyvolume.serialize.array_sequence_to_binary_or_json(empty_array)) == list
+
+    value = np.asarray(5)
+    assert ipyvolume.serialize.array_sequence_to_binary_or_json(value) == 5
+    
+    value = np.asarray(5)
+    assert ipyvolume.serialize.array_sequence_to_binary_or_json(value) == 5
+
 def test_figure():
     f1 = p3.figure()
     f2 = p3.figure(2)