fixtures: deprecate pytest._fillfuncargs function

This function is exposed and kept alive for the oejskit plugin which is
abandoned and no longer works with recent plugins, so let's prepare to
completely remove it.

changelog/7097.deprecation.rst

@@ -0,0 +1,6 @@
+The ``pytest._fillfuncargs`` function is now deprecated. This function was kept
+for backward compatibility with an older plugin.
+
+It's functionality is not meant to be used directly, but if you must replace
+it, use `function._request._fillfixtures()` instead, though note this is not
+a public API and may break in the future.

doc/en/deprecations.rst

@@ -20,6 +20,19 @@ Below is a complete list of all pytest features which are considered deprecated.
 :ref:`standard warning filters <warnings>`.
 
 
+The ``pytest._fillfuncargs`` function
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. deprecated:: 5.5
+
+This function was kept for backward compatibility with an older plugin.
+
+It's functionality is not meant to be used directly, but if you must replace
+it, use `function._request._fillfixtures()` instead, though note this is not
+a public API and may break in the future.
+
+
+
 ``--no-print-logs`` command-line option
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

src/_pytest/deprecated.py

@@ -25,6 +25,11 @@
     "since pytest 2.3 - use the newer attribute instead."
 )
 
+FILLFUNCARGS = PytestDeprecationWarning(
+    "The `_fillfuncargs` function is deprecated, use "
+    "function._request._fillfixtures() instead if you must."
+)
+
 RESULT_LOG = PytestDeprecationWarning(
     "--result-log is deprecated, please try the new pytest-reportlog plugin.\n"
     "See https://docs.pytest.org/en/latest/deprecations.html#result-log-result-log for more information."

src/_pytest/fixtures.py

@@ -28,6 +28,7 @@
 from _pytest.compat import NOTSET
 from _pytest.compat import safe_getattr
 from _pytest.compat import TYPE_CHECKING
+from _pytest.deprecated import FILLFUNCARGS
 from _pytest.deprecated import FIXTURE_POSITIONAL_ARGUMENTS
 from _pytest.deprecated import FUNCARGNAMES
 from _pytest.mark import ParameterSet
@@ -276,6 +277,7 @@ def reorder_items_atscope(items, argkeys_cache, items_by_argkey, scopenum):
 
 def fillfixtures(function):
     """ fill missing funcargs for a test function. """
+    warnings.warn(FILLFUNCARGS, stacklevel=2)
     function._request._fillfixtures()
 
 

testing/deprecated_test.py

@@ -1,4 +1,5 @@
 import inspect
+from unittest import mock
 
 import pytest
 from _pytest import deprecated
@@ -146,3 +147,11 @@ def test_foo():
     )
 
     assert_no_print_logs(testdir, ())
+
+
+def test__fillfuncargs_is_deprecated() -> None:
+    with pytest.warns(
+        pytest.PytestDeprecationWarning,
+        match="The `_fillfuncargs` function is deprecated",
+    ):
+        pytest._fillfuncargs(mock.Mock())