Replace importlib_metadata with importlib.metadata on Python 3.8+

Fixes pytest-dev#5537

changelog/5537.bugfix.rst

@@ -0,0 +1,2 @@
+Replace ``importlib_metadata`` backport with ``importlib.metadata`` from the
+standard library on Python 3.8+.

setup.py

@@ -11,7 +11,7 @@
     'pathlib2>=2.2.0;python_version<"3.6"',
     'colorama;sys_platform=="win32"',
     "pluggy>=0.12,<1.0",
-    "importlib-metadata>=0.12",
+    'importlib-metadata>=0.12;python_version<"3.8"',
     "wcwidth",
 ]
 

src/_pytest/config/__init__.py

@@ -9,7 +9,6 @@
 import warnings
 from functools import lru_cache
 
-import importlib_metadata
 import py
 from packaging.version import Version
 from pluggy import HookimplMarker
@@ -29,6 +28,11 @@
 from _pytest.outcomes import Skipped
 from _pytest.warning_types import PytestConfigWarning
 
+if sys.version_info >= (3, 8):
+    from importlib import metadata
+else:
+    import importlib_metadata as metadata
+
 hookimpl = HookimplMarker("pytest")
 hookspec = HookspecMarker("pytest")
 
@@ -772,7 +776,7 @@ def _mark_plugins_for_rewrite(self, hook):
 
         package_files = (
             str(file)
-            for dist in importlib_metadata.distributions()
+            for dist in metadata.distributions()
             if any(ep.group == "pytest11" for ep in dist.entry_points)
             for file in dist.files or []
         )

testing/acceptance_test.py

@@ -4,13 +4,17 @@
 import types
 
 import attr
-import importlib_metadata
 import py
 
 import pytest
 from _pytest.main import ExitCode
 from _pytest.warnings import SHOW_PYTEST_WARNINGS_ARG
 
+if sys.version_info >= (3, 8):
+    from importlib import metadata
+else:
+    import importlib_metadata as metadata
+
 
 def prepend_pythonpath(*dirs):
     cur = os.getenv("PYTHONPATH")
@@ -137,7 +141,7 @@ class DummyDist:
         def my_dists():
             return (DummyDist(entry_points),)
 
-        monkeypatch.setattr(importlib_metadata, "distributions", my_dists)
+        monkeypatch.setattr(metadata, "distributions", my_dists)
         params = ("-p", "mycov") if load_cov_early else ()
         testdir.runpytest_inprocess(*params)
         if load_cov_early:

testing/test_assertion.py

@@ -172,7 +172,11 @@ def check(values, value):
                 return check
             """,
             "mainwrapper.py": """\
-            import pytest, importlib_metadata
+            import pytest, sys
+            if sys.version_info >= (3, 8):
+                from importlib import metadata
+            else:
+                import importlib_metadata as metadata
 
             class DummyEntryPoint(object):
                 name = 'spam'
@@ -192,7 +196,7 @@ class DummyDistInfo(object):
             def distributions():
                 return (DummyDistInfo(),)
 
-            importlib_metadata.distributions = distributions
+            metadata.distributions = distributions
             pytest.main()
             """,
             "test_foo.py": """\

testing/test_config.py

@@ -1,8 +1,6 @@
 import sys
 import textwrap
 
-import importlib_metadata
-
 import _pytest._code
 import pytest
 from _pytest.config import _iter_rewritable_modules
@@ -12,6 +10,11 @@
 from _pytest.config.findpaths import getcfg
 from _pytest.main import ExitCode
 
+if sys.version_info >= (3, 8):
+    from importlib import metadata
+else:
+    import importlib_metadata as metadata
+
 
 class TestParseIni:
     @pytest.mark.parametrize(
@@ -540,7 +543,7 @@ class Dist:
     def my_dists():
         return (Dist,)
 
-    monkeypatch.setattr(importlib_metadata, "distributions", my_dists)
+    monkeypatch.setattr(metadata, "distributions", my_dists)
     testdir.makeconftest(
         """
         pytest_plugins = "mytestplugin",
@@ -570,7 +573,7 @@ class Distribution:
     def distributions():
         return (Distribution(),)
 
-    monkeypatch.setattr(importlib_metadata, "distributions", distributions)
+    monkeypatch.setattr(metadata, "distributions", distributions)
     with pytest.raises(ImportError):
         testdir.parseconfig()
 
@@ -594,7 +597,7 @@ class Distribution:
     def distributions():
         return (Distribution(),)
 
-    monkeypatch.setattr(importlib_metadata, "distributions", distributions)
+    monkeypatch.setattr(metadata, "distributions", distributions)
     testdir.parseconfig()
 
 
@@ -619,7 +622,7 @@ class Distribution:
     def distributions():
         return (Distribution(),)
 
-    monkeypatch.setattr(importlib_metadata, "distributions", distributions)
+    monkeypatch.setattr(metadata, "distributions", distributions)
     args = ("-p", "no:mytestplugin") if block_it else ()
     config = testdir.parseconfig(*args)
     config.pluginmanager.import_plugin("mytestplugin")
@@ -655,7 +658,7 @@ def distributions():
         return (Distribution(),)
 
     monkeypatch.setenv("PYTEST_DISABLE_PLUGIN_AUTOLOAD", "1")
-    monkeypatch.setattr(importlib_metadata, "distributions", distributions)
+    monkeypatch.setattr(metadata, "distributions", distributions)
     monkeypatch.setitem(sys.modules, "mytestplugin", PseudoPlugin())
     config = testdir.parseconfig(*parse_args)
     has_loaded = config.pluginmanager.get_plugin("mytestplugin") is not None

testing/test_entry_points.py

@@ -1,7 +1,12 @@
-import importlib_metadata
+import sys
+
+if sys.version_info >= (3, 8):
+    from importlib import metadata
+else:
+    import importlib_metadata as metadata
 
 
 def test_pytest_entry_points_are_identical():
-    dist = importlib_metadata.distribution("pytest")
+    dist = metadata.distribution("pytest")
     entry_map = {ep.name: ep for ep in dist.entry_points}
     assert entry_map["pytest"].value == entry_map["py.test"].value