old_contents: import sys
  import unittest
  import importlib_metadata
  
  try:
      from contextlib import ExitStack
  except ImportError:
      from contextlib2 import ExitStack
  
  from importlib_resources import path
  
  
  class BespokeLoader:
      archive = 'bespoke'
  
  
  class TestZip(unittest.TestCase):
      def setUp(self):
          # Find the path to the example.*.whl so we can add it to the front of
          # sys.path, where we'll then try to find the metadata thereof.
          self.resources = ExitStack()
          self.addCleanup(self.resources.close)
          wheel = self.resources.enter_context(
              path('importlib_metadata.tests.data',
                   'example-21.12-py3-none-any.whl'))
          sys.path.insert(0, str(wheel))
          self.resources.callback(sys.path.pop, 0)
  
      def test_zip_version(self):
          self.assertEqual(importlib_metadata.version('example'), '21.12')
  
      def test_zip_entry_points(self):
          parser = importlib_metadata.entry_points('example')
          entry_point = parser.get('console_scripts', 'example')
          self.assertEqual(entry_point, 'example:main')
  
      def test_missing_metadata(self):
          distribution = importlib_metadata.distribution('example')
          self.assertIsNone(distribution.read_text('does not exist'))
  
new_contents: import sys
  import unittest
  import importlib_metadata
  
  try:
      from contextlib import ExitStack
  except ImportError:
      from contextlib2 import ExitStack
  
  from importlib_resources import path
  
  
  class BespokeLoader:
      archive = 'bespoke'
  
  
  class TestZip(unittest.TestCase):
      def setUp(self):
          # Find the path to the example.*.whl so we can add it to the front of
          # sys.path, where we'll then try to find the metadata thereof.
          self.resources = ExitStack()
          self.addCleanup(self.resources.close)
          wheel = self.resources.enter_context(
              path('importlib_metadata.tests.data',
                   'example-21.12-py3-none-any.whl'))
          sys.path.insert(0, str(wheel))
          self.resources.callback(sys.path.pop, 0)
  
      def test_zip_version(self):
          self.assertEqual(importlib_metadata.version('example'), '21.12')
  
      def test_zip_entry_points(self):
          parser = importlib_metadata.entry_points('example')
          entry_point = parser.get('console_scripts', 'example')
          self.assertEqual(entry_point, 'example:main')
  
      def test_missing_metadata(self):
          distribution = importlib_metadata.distribution('example')
          self.assertIsNone(distribution.read_text('does not exist'))
  
      def test_case_insensitive(self):
          self.assertEqual(importlib_metadata.version('Example'), '21.12')
  
subject: Add test capturing new expectation. Ref #20.