test(refactor): drop pkg_resources

Author: nedbat

tests/modules/process_test/try_execfile.py

@@ -29,8 +29,7 @@
 
 from typing import Any, List
 
-# sys.path varies by execution environments.  Coverage.py uses setuptools to
-# make console scripts, which means pkg_resources is imported.  pkg_resources
+# sys.path varies by execution environments.  Some installation libraries
 # removes duplicate entries from sys.path.  So we do that too, since the extra
 # entries don't affect the running of the program.
 

tests/test_process.py

@@ -850,16 +850,19 @@ def test_coverage_custom_script(self) -> None:
         platform.python_version().endswith("+"),
         reason="setuptools barfs on dev versions: https://github.com/pypa/packaging/issues/678"
         # https://github.com/nedbat/coveragepy/issues/1556
-        # TODO: get rid of pkg_resources
     )
     def test_bug_862(self) -> None:
-        # This simulates how pyenv and pyenv-virtualenv end up creating the
-        # coverage executable.
-        self.make_file("elsewhere/bin/fake-coverage", """\
-            #!{executable}
-            import sys, pkg_resources
-            sys.exit(pkg_resources.load_entry_point('coverage', 'console_scripts', 'coverage')())
-            """.format(executable=sys.executable))
+        # This used to simulate how pyenv and pyenv-virtualenv create the
+        # coverage executable.  Now the code shows how venv does it.
+        self.make_file("elsewhere/bin/fake-coverage", f"""\
+            #!{sys.executable}
+            import re
+            import sys
+            from coverage.cmdline import main
+            if __name__ == '__main__':
+                sys.argv[0] = re.sub(r'(-script\\.pyw|\\.exe)?$', '', sys.argv[0])
+                sys.exit(main())
+            """)
         os.chmod("elsewhere/bin/fake-coverage", stat.S_IREAD | stat.S_IEXEC)
         os.symlink("elsewhere", "somewhere")
         self.make_file("foo.py", "print('inside foo')")

tests/test_venv.py

@@ -105,40 +105,33 @@ def sixth(x):
             setup(
                 name='testcov',
                 packages=['testcov'],
-                namespace_packages=['testcov'],
             )
             """)
+        # https://packaging.python.org/en/latest/guides/packaging-namespace-packages/#pkgutil-style-namespace-packages
         make_file("bug888/app/testcov/__init__.py", """\
-            try:  # pragma: no cover
-                __import__('pkg_resources').declare_namespace(__name__)
-            except ImportError:  # pragma: no cover
-                from pkgutil import extend_path
-                __path__ = extend_path(__path__, __name__)
+            __path__ = __import__('pkgutil').extend_path(__path__, __name__)
             """)
-        make_file("bug888/app/testcov/main.py", """\
-            try:  # pragma: no cover
-                entry_points = __import__("pkg_resources").iter_entry_points('plugins')
-            except ImportError:  # pragma: no cover
-                import importlib.metadata
-                entry_points = importlib.metadata.entry_points(group="plugins")
-            for entry_point in entry_points:
+        if env.PYVERSION < (3, 10):
+            get_plugins = "entry_points['plugins']"
+        else:
+            get_plugins = "entry_points.select(group='plugins')"
+        make_file("bug888/app/testcov/main.py", f"""\
+            import importlib.metadata
+            entry_points = importlib.metadata.entry_points()
+            for entry_point in {get_plugins}:
                 entry_point.load()()
             """)
         make_file("bug888/plugin/setup.py", """\
             from setuptools import setup
             setup(
                 name='testcov-plugin',
                 packages=['testcov'],
-                namespace_packages=['testcov'],
                 entry_points={'plugins': ['testp = testcov.plugin:testp']},
             )
             """)
+        # https://packaging.python.org/en/latest/guides/packaging-namespace-packages/#pkgutil-style-namespace-packages
         make_file("bug888/plugin/testcov/__init__.py", """\
-            try:  # pragma: no cover
-                __import__('pkg_resources').declare_namespace(__name__)
-            except ImportError:  # pragma: no cover
-                from pkgutil import extend_path
-                __path__ = extend_path(__path__, __name__)
+            __path__ = __import__('pkgutil').extend_path(__path__, __name__)
             """)
         make_file("bug888/plugin/testcov/plugin.py", """\
             def testp():