Add support for flake8 version >= 5.0.0. Fix test case to run with re…

…cent vesions of flake8, fix summary line to show hte installed flake8 pluings

flake8_html/plugin.py

@@ -17,6 +17,7 @@
 from operator import attrgetter
 from collections import namedtuple, Counter
 
+import flake8
 from pygments import highlight
 from collections import defaultdict
 from pygments.lexers import PythonLexer
@@ -278,14 +279,23 @@ def write_index(self):
                 key=lambda e: (e.highest_sev, -e.error_count)
             ),
             now=datetime.datetime.now(),
-            versions=self.option_manager.generate_versions(),
+            versions=self._get_plugin_version_summary(),
             highest_sev=highest_sev,
             title=self.options.htmltitle,
         )
         indexfile = os.path.join(self.outdir, 'index.html')
         with codecs.open(indexfile, 'w', encoding='utf8') as f:
             f.write(rendered)
 
+    def _get_plugin_version_summary(self):
+        option_manager = self.option_manager
+        if flake8.__version_info__ < (5, 0, 0):
+            return option_manager.generate_versions()
+        else:
+            # Below return info prefixed with "Installed with:". This is different from
+            # option_manager.generate_versions() but using this as it is a cleaner way
+            return option_manager.parser.epilog
+
     @classmethod
     def add_options(cls, options):
         """Add a --htmldir option to the OptionsManager."""

tests/test_flake8_html.py

@@ -7,6 +7,7 @@
 import shutil
 import contextlib
 
+import flake8
 import pytest
 from flake8.main.cli import main
 
@@ -50,7 +51,10 @@ def chdir(dest):
 def test_report(bad_sourcedir, tmpdir):
     """Test that a report on a bad file creates the expected files."""
     with chdir(bad_sourcedir), pytest.raises(SystemExit) as excinfo:
-        main(['--exit-zero', '--format=html', '--htmldir=%s' % tmpdir, '.'])
+        code = main(['--exit-zero', '--format=html', '--htmldir=%s' % tmpdir, '.'])
+        # earlier flake8 version were raising the SystemExit, now raise it explicitly to cover recent versions too
+        if flake8.__version_info__ >= (5, 0, 0):
+            raise SystemExit(code)
     assert excinfo.value.code == 0
     names = ('index.html', 'styles.css', 'bad.report.html', 'bad.source.html')
     written = os.listdir(str(tmpdir))