Correctly handle null values for arguments

teklia_toolbox/config.py

@@ -95,9 +95,8 @@ class ConfigParser:
             for name in data:
                 if name not in self.options:
                     errors[name] = "This option does not exist"
-
         for name, option in self.options.items():
-            if name in data:
+            if data.get(name) is not None:
                 value = data[name]
             elif option.default is UNSET:
                 errors[name] = "This option is required"

tests/test_config.py

@@ -82,3 +82,24 @@ class TestConfigParser(TestCase):
                 "unknownthing": "This option does not exist",
             },
         )
+
+    def test_parse_null_no_default(self):
+        parser = ConfigParser()
+        parser.add_option("something", type=str)
+        with self.assertRaises(ConfigurationError) as context:
+            parser.parse_data({"something": None})
+
+        self.assertDictEqual(
+            context.exception.errors,
+            {
+                "something": "This option is required",
+            },
+        )
+
+    def test_parse_null_with_default(self):
+        parser = ConfigParser()
+        parser.add_option("something", type=str, default=None)
+        self.assertDictEqual(
+            parser.parse_data({"something": None}),
+            {"something": None},
+        )