From 66ac22ecf6a1925f2f57dc390b4251e2c89603a8 Mon Sep 17 00:00:00 2001
From: Meir Tseitlin <meir@imubit.com>
Date: Fri, 14 May 2021 14:10:52 -0500
Subject: [PATCH] allow removing items or sources from config

---
 confuse/core.py    | 31 +++++++++++++++++++++++++++++++
 test/test_views.py | 24 ++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/confuse/core.py b/confuse/core.py
index c63b1a9..fe37ffd 100644
--- a/confuse/core.py
+++ b/confuse/core.py
@@ -87,6 +87,11 @@ def add(self, value):
         """
         raise NotImplementedError
 
+    def remove(self, obj):
+        """Remove source or key from config
+        """
+        raise NotImplementedError
+
     def set(self, value):
         """*Override* the value for this configuration view. The
         specified value is added as the highest-priority configuration
@@ -136,6 +141,11 @@ def __setitem__(self, key, value):
         """
         self.set({key: value})
 
+    def __delitem__(self, key):
+        """Remove value from config by key.
+        """
+        self.remove(key)
+
     def __contains__(self, key):
         return self[key].exists()
 
@@ -439,6 +449,22 @@ def __init__(self, sources):
     def add(self, obj):
         self.sources.append(ConfigSource.of(obj))
 
+    def remove(self, obj):
+        """Remove source or key from configuration
+        """
+        if isinstance(obj, ConfigSource):
+            if obj.default:
+                raise ConfigError(u'Cannot remove default source')
+            self.sources.remove(obj)
+        elif isinstance(obj, util.STRING):
+            for source in self.sources:
+                if isinstance(source, ConfigSource) and obj in source:
+                    del source[obj]
+        else:
+            raise ConfigError(u'Unrecognized obj {0}'.format(
+                obj
+            ))
+
     def set(self, value):
         self.sources.insert(0, ConfigSource.of(value))
 
@@ -514,6 +540,11 @@ def set(self, value):
     def add(self, value):
         self.parent.add({self.key: value})
 
+    def remove(self, key):
+        value = self.parent[self.key].get()
+        del value[key]
+        self.set(value)
+
     def root(self):
         return self.parent.root()
 
diff --git a/test/test_views.py b/test/test_views.py
index 860633c..0bb12d0 100644
--- a/test/test_views.py
+++ b/test/test_views.py
@@ -241,6 +241,30 @@ def test_override_list_index(self):
         self.assertEqual(config['foo'][1].get(), 'bar')
 
 
+class DeleteTest(unittest.TestCase):
+
+    def test_remove(self):
+        config = _root({'foo': 'bar', 'qux': 'baz'})
+        config.remove('foo')
+        with self.assertRaises(confuse.NotFoundError):
+            config['foo'].get()
+        self.assertEqual(set(config.keys()), set(['qux']))
+
+    def test_del(self):
+        config = _root({'foo': 'bar', 'qux': 'baz'})
+        del config['foo']
+        with self.assertRaises(confuse.NotFoundError):
+            config['foo'].get()
+        self.assertEqual(set(config.keys()), set(['qux']))
+
+    def test_nested_remove(self):
+        config = _root({'foo': {'bar': {'x': 'y', 'a': 'b'}, 'qux': 'baz'}})
+        del config['foo']['bar']['x']
+        self.assertEqual(config['foo']['bar'].get(), {'a': 'b'})
+        config['foo']['bar'].remove('a')
+        self.assertEqual(config['foo']['bar'].get(), {})
+
+
 class BuildNamespaceDictTests(unittest.TestCase):
     def test_pure_dicts(self):
         config = {'foo': {'bar': 1}}