From de05982393e881e52f2f1f1d407ff58822c06aa2 Mon Sep 17 00:00:00 2001
From: Francois Dang Ngoc <francois.dangngoc@gmail.com>
Date: Fri, 2 Dec 2016 11:20:28 -0500
Subject: [PATCH] Implemented contains method #97

---
 pyhocon/config_tree.py    |  3 +++
 tests/test_config_tree.py | 18 ++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/pyhocon/config_tree.py b/pyhocon/config_tree.py
index 76ef19fa..37c12e1e 100644
--- a/pyhocon/config_tree.py
+++ b/pyhocon/config_tree.py
@@ -291,6 +291,9 @@ def __getitem__(self, item):
             raise KeyError(item)
         return val
 
+    def __contains__(self, item):
+        return self._get(self.parse_key(item), default=NoneValue) is not NoneValue
+
     def with_fallback(self, config):
         """
         return a new config with fallback on config
diff --git a/tests/test_config_tree.py b/tests/test_config_tree.py
index 372e8975..251a7ae6 100644
--- a/tests/test_config_tree.py
+++ b/tests/test_config_tree.py
@@ -198,3 +198,21 @@ def test_plain_ordered_dict(self):
         d['a']['b.c'] = [OrderedDict(), 2]
         d['a']['b.c'][0]['c.d'] = 1
         assert config_tree.as_plain_ordered_dict() == d
+
+    def test_contains(self):
+        config_tree = ConfigTree()
+        config_tree.put('a.b', 5)
+        config_tree.put('a.c', None)
+        assert 'a' in config_tree
+        assert 'a.b' in config_tree
+        assert 'a.c' in config_tree
+        assert 'a.b.c' not in config_tree
+
+    def test_contains_with_quoted_keys(self):
+        config_tree = ConfigTree()
+        config_tree.put('a.b."c.d"', 5)
+        assert 'a' in config_tree
+        assert 'a.b' in config_tree
+        assert 'a.c' not in config_tree
+        assert 'a.b."c.d"' in config_tree
+        assert 'a.b.c.d' not in config_tree