Add pipenv language support to pre-commit

- Implement pipenv language module in pre-commit
- Update workflows to include pipenv language tests
- Add pipenv language to allowed languages in testing script
- Create comprehensive test suite for pipenv language support

tests/languages/pipenv_test.py

@@ -0,0 +1,74 @@
+from __future__ import annotations
+
+import os
+import sys
+from unittest import mock
+
+import pytest
+
+import pre_commit.constants as C
+from pre_commit.languages import pipenv
+from pre_commit.prefix import Prefix
+from pre_commit.util import cmd_output
+from testing.language_helpers import run_language
+
+def test_health_check_no_pipfile(tmp_path):
+    with pytest.raises(AssertionError) as excinfo:
+        pipenv.health_check(Prefix(str(tmp_path)), C.DEFAULT)
+    assert '`language: pipenv` requires a Pipfile' in str(excinfo.value)
+
+def _make_pipfile(path):
+    with open(os.path.join(path, 'Pipfile'), 'w') as f:
+        f.write('''\
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+requests = "*"
+
+[dev-packages]
+pytest = "*"
+
+[requires]
+python_version = "3.9"
+''')
+
+def test_health_check_with_pipfile(tmp_path):
+    _make_pipfile(tmp_path)
+    assert pipenv.health_check(Prefix(str(tmp_path)), C.DEFAULT) is None
+
+def test_install_environment(tmp_path):
+    _make_pipfile(tmp_path)
+    
+    with mock.patch.object(pipenv, 'cmd_output_b') as mocked:
+        pipenv.install_environment(
+            Prefix(str(tmp_path)), 
+            C.DEFAULT, 
+            ['black']
+        )
+        
+        python_version = f"{sys.version_info[0]}.{sys.version_info[1]}"
+        assert mocked.call_args_list == [
+            mock.call('pipenv', '--python', python_version),
+            mock.call('pipenv', 'install', '--dev'),
+            mock.call('pipenv', 'install', 'black'),
+        ]
+
+def test_run_hook(tmp_path):
+    _make_pipfile(tmp_path)
+    
+    # Create a simple Python script
+    script = '''\
+#!/usr/bin/env python
+print("Hello from pipenv!")
+'''
+    tmp_path.joinpath('script.py').write_text(script)
+    
+    ret = run_language(
+        tmp_path,
+        pipenv,
+        'python script.py',
+    )
+    assert ret == (0, b'Hello from pipenv!\n')