Fixes issue #11282

changelog/11282.bugfix.rst

@@ -0,0 +1,3 @@
+Fixed returning "None" as the default value for a config option when "None" is explicitly
+provided as the default while creating the config option. If no default value is provided
+at the time of creating the config option, then a default based on the option type is returned

src/_pytest/config/__init__.py

@@ -1521,11 +1521,7 @@ class Config:
             try:
                 value = self.inicfg[name]
             except KeyError:
-                if default is not None:
+                return default
-                    return default
-                if type is None:
-                    return ""
-                return []
         else:
             value = override_value
         # Coerce the values based on types.

src/_pytest/config/argparsing.py

@@ -27,6 +27,14 @@ from _pytest.deprecated import check_ispytest
 FILE_OR_DIR = "file_or_dir"
 
 
+class Notset:
+    def __repr__(self) -> str:
+        return "<notset>"
+
+
+notset = Notset()
+
+
 @final
 class Parser:
     """Parser for command line arguments and ini-file values.
@@ -176,7 +184,7 @@ class Parser:
         type: Optional[
             Literal["string", "paths", "pathlist", "args", "linelist", "bool"]
         ] = None,
-        default: Any = None,
+        default: Any = notset,
     ) -> None:
         """Register an ini-file option.
 
@@ -203,6 +211,20 @@ class Parser:
         :py:func:`config.getini(name) <pytest.Config.getini>`.
         """
         assert type in (None, "string", "paths", "pathlist", "args", "linelist", "bool")
+        if default is notset:
+            if type is None:
+                default = ""
+            else:
+                if type in ["paths", "pathlist", "args", "linelist"]:
+                    default = []
+                elif type == "bool":
+                    default = False
+                elif type == "string":
+                    default = ""
+                else:
+                    # unknown type will default to None
+                    default = None
+
         self._inidict[name] = (help, type, default)
         self._ininames.append(name)
 

testing/test_config.py

@@ -857,6 +857,53 @@ class TestConfigAPI:
         assert len(values) == 2
         assert values == ["456", "123"]
 
+    def test_addini_default_values(self, pytester: Pytester) -> None:
+        """Tests the default values for configuration based on
+        config type
+        """
+
+        pytester.makeconftest(
+            """
+            def pytest_addoption(parser):
+                parser.addini("linelist1", "", type="linelist")
+                parser.addini("paths1", "", type="paths")
+                parser.addini("pathlist1", "", type="pathlist")
+                parser.addini("args1", "", type="args")
+                parser.addini("bool1", "", type="bool")
+                parser.addini("string1", "", type="string")
+                parser.addini("none_1", "", type="linelist", default=None)
+                parser.addini("none_2", "", default=None)
+                parser.addini("no_type", "")
+        """
+        )
+
+        config = pytester.parseconfig()
+        # default for linelist, paths, pathlist and args is []
+        value = config.getini("linelist1")
+        assert value == []
+        value = config.getini("paths1")
+        assert value == []
+        value = config.getini("pathlist1")
+        assert value == []
+        value = config.getini("args1")
+        assert value == []
+        # default for bool is False
+        value = config.getini("bool1")
+        assert value is False
+        # default for string is ""
+        value = config.getini("string1")
+        assert value == ""
+        # should return None if None is explicity set as default value
+        # irrespective of the type argument
+        value = config.getini("none_1")
+        assert value is None
+        value = config.getini("none_2")
+        assert value is None
+        # in case no type is provided and no default set
+        # treat it as string and default value will be ""
+        value = config.getini("no_type")
+        assert value == ""
+
     def test_confcutdir_check_isdir(self, pytester: Pytester) -> None:
         """Give an error if --confcutdir is not a valid directory (#2078)"""
         exp_match = r"^--confcutdir must be a directory, given: "