From d2d902be4085a517077be3a88f60486327373736 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Rivet?=
 <Marc-Andre-Rivet@users.noreply.github.com>
Date: Wed, 10 Apr 2019 22:18:57 -0400
Subject: [PATCH] Issue148 - `0` children regression in dash==0.40.0 (#150)

---
 CHANGELOG.md         |  4 ++++
 src/TreeContainer.js |  2 +-
 tests/test_render.py | 22 +++++++++++++++++++++-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f8b184ef9..c61267b55e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased]
+### Fixed
+- Fix regression for `children=0` case [#148](https://github.com/plotly/dash-renderer/issues/148)
+
 ## [0.22.0] - 2019-04-10
 ### Added
 - Added support for clientside callbacks [#143](https://github.com/plotly/dash-renderer/pull/143)
diff --git a/src/TreeContainer.js b/src/TreeContainer.js
index 6083a30171..e6244ae55c 100644
--- a/src/TreeContainer.js
+++ b/src/TreeContainer.js
@@ -33,7 +33,7 @@ const createContainer = component => isSimpleComponent(component) ?
 
 class TreeContainer extends Component {
     getChildren(components) {
-        if (!components) {
+        if (isNil(components)) {
             return null;
         }
 
diff --git a/tests/test_render.py b/tests/test_render.py
index 61fb8c8cba..9b2e04abc2 100644
--- a/tests/test_render.py
+++ b/tests/test_render.py
@@ -104,7 +104,7 @@ def request_queue_assertions(
 
         if expected_length is not None:
             self.assertEqual(len(request_queue), expected_length)
-    
+
     def test_initial_state(self):
         app = Dash(__name__)
         app.layout = html.Div([
@@ -475,6 +475,26 @@ def test_initial_state(self):
 
         assert_clean_console(self)
 
+    def test_array_of_falsy_child(self):
+        app = Dash(__name__)
+        app.layout = html.Div(id='nully-wrapper', children=[0])
+
+        self.startServer(app)
+
+        self.wait_for_text_to_equal('#nully-wrapper', '0')
+
+        assert_clean_console(self)
+
+    def test_of_falsy_child(self):
+        app = Dash(__name__)
+        app.layout = html.Div(id='nully-wrapper', children=0)
+
+        self.startServer(app)
+
+        self.wait_for_text_to_equal('#nully-wrapper', '0')
+
+        assert_clean_console(self)
+
     def test_simple_callback(self):
         app = Dash(__name__)
         app.layout = html.Div([