From a4ae953dca38da768bcd1786aeba84bada32efb4 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 23 Jun 2022 16:56:20 -0400
Subject: [PATCH 1/3] Add xfail test capturing new expectation.

---
 tests/fixtures.py  | 16 ++++++++++++++++
 tests/test_main.py | 10 ++++++++++
 2 files changed, 26 insertions(+)

diff --git a/tests/fixtures.py b/tests/fixtures.py
index 08a478ac..6d9a9d2b 100644
--- a/tests/fixtures.py
+++ b/tests/fixtures.py
@@ -5,6 +5,7 @@
 import pathlib
 import tempfile
 import textwrap
+import functools
 import contextlib
 
 from .py39compat import FS_NONASCII
@@ -294,3 +295,18 @@ def setUp(self):
         # Add self.zip_name to the front of sys.path.
         self.resources = contextlib.ExitStack()
         self.addCleanup(self.resources.close)
+
+
+def parameterize(*args_set):
+    """Run test method with a series of parameters."""
+
+    def wrapper(func):
+        @functools.wraps(func)
+        def _inner(self):
+            for args in args_set:
+                with self.subTest(**args):
+                    func(self, **args)
+
+        return _inner
+
+    return wrapper
diff --git a/tests/test_main.py b/tests/test_main.py
index 215662dd..041220f1 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,6 +1,7 @@
 import re
 import json
 import pickle
+import pytest
 import unittest
 import warnings
 import importlib
@@ -50,6 +51,15 @@ def test_new_style_classes(self):
         self.assertIsInstance(Distribution, type)
         self.assertIsInstance(MetadataPathFinder, type)
 
+    @pytest.mark.xfail(reason="Not implemented")
+    @fixtures.parameterize(
+        dict(name=None),
+        dict(name=''),
+    )
+    def test_invalid_inputs_to_from_name(self, name):
+        with self.assertRaises(Exception):
+            Distribution.from_name(name)
+
 
 class ImportTests(fixtures.DistInfoPkg, unittest.TestCase):
     def test_import_nonexistent_module(self):

From 71cec30ef80047b5fdb786bba2868a0b12c8c7d0 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 23 Jun 2022 16:57:53 -0400
Subject: [PATCH 2/3] Add a validator to Distribution.from_name

---
 importlib_metadata/__init__.py | 5 ++++-
 setup.cfg                      | 1 +
 tests/test_main.py             | 2 --
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/importlib_metadata/__init__.py b/importlib_metadata/__init__.py
index 29ce1175..1ecab312 100644
--- a/importlib_metadata/__init__.py
+++ b/importlib_metadata/__init__.py
@@ -29,6 +29,8 @@
 from importlib import import_module
 from importlib.abc import MetaPathFinder
 from itertools import starmap
+from pydantic import Field, validate_arguments
+from pydantic.typing import Annotated
 from typing import List, Mapping, Optional, Union
 
 
@@ -548,7 +550,8 @@ def locate_file(self, path):
         """
 
     @classmethod
-    def from_name(cls, name):
+    @validate_arguments
+    def from_name(cls, name: Annotated[str, Field(min_length=1)]):
         """Return the Distribution for the given package name.
 
         :param name: The name of the distribution package to search for.
diff --git a/setup.cfg b/setup.cfg
index efd0a36d..75dc6bc2 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,6 +19,7 @@ python_requires = >=3.7
 install_requires =
 	zipp>=0.5
 	typing-extensions>=3.6.4; python_version < "3.8"
+	pydantic
 
 [options.packages.find]
 exclude =
diff --git a/tests/test_main.py b/tests/test_main.py
index 041220f1..921f5d9c 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,7 +1,6 @@
 import re
 import json
 import pickle
-import pytest
 import unittest
 import warnings
 import importlib
@@ -51,7 +50,6 @@ def test_new_style_classes(self):
         self.assertIsInstance(Distribution, type)
         self.assertIsInstance(MetadataPathFinder, type)
 
-    @pytest.mark.xfail(reason="Not implemented")
     @fixtures.parameterize(
         dict(name=None),
         dict(name=''),

From fdbcb793b7f02e57c04b239be5ddf888463eb92d Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Thu, 23 Jun 2022 17:51:39 -0400
Subject: [PATCH 3/3] Add pydantic as a build dependency as possible workaround
 for failing CI build.

---
 pyproject.toml | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/pyproject.toml b/pyproject.toml
index 60de2424..1ee8e047 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,11 @@
 [build-system]
-requires = ["setuptools>=56", "setuptools_scm[toml]>=3.4.1"]
+requires = [
+	"setuptools>=56",
+	"setuptools_scm[toml]>=3.4.1",
+	# temporary workaround for dependency race in setuptools_scm
+	# https://github.com/python/importlib_metadata/pull/389#issuecomment-1164912426
+	'pydantic; python_version < "3.8"',
+]
 build-backend = "setuptools.build_meta"
 
 [tool.black]