fix: use pypi importlib_metadata on python < 3.10 (#1467)

news/1467.bugfix.md

@@ -0,0 +1 @@
+Use `importlib-metadata` from PyPI for Python < 3.10.

pyproject.toml

@@ -26,7 +26,7 @@ dependencies = [
     "cachecontrol[filecache]>=0.12.11",
     "tomli>=1.1.0; python_version < \"3.11\"",
     "typing-extensions; python_version < \"3.8\"",
-    "importlib-metadata<5.0.0; python_version < \"3.8\"",
+    "importlib-metadata>=3.6; python_version < \"3.10\"",
     "certifi>=2022.6.15",
 ]
 name = "pdm"

src/pdm/compat.py

@@ -7,12 +7,16 @@
 
 
 if sys.version_info >= (3, 8):
-    import importlib.metadata as importlib_metadata
     from typing import Literal, Protocol, TypedDict
 else:
-    import importlib_metadata
     from typing_extensions import Literal, Protocol, TypedDict
 
+if sys.version_info >= (3, 10):
+    import importlib.metadata as importlib_metadata
+else:
+    import importlib_metadata
+
+
 Distribution = importlib_metadata.Distribution
 
 

src/pdm/core.py

@@ -14,7 +14,7 @@
 import pkgutil
 import sys
 from pathlib import Path
-from typing import Any, cast
+from typing import Any, Iterable, cast
 
 from resolvelib import Resolver
 
@@ -238,10 +238,11 @@ def my_plugin(core: pdm.core.Core) -> None:
                 ...
             ```
         """
-        entry_points = importlib_metadata.entry_points()
-        for plugin in itertools.chain(
-            entry_points.get("pdm", []), entry_points.get("pdm.plugin", [])
-        ):
+        entry_points: Iterable[importlib_metadata.EntryPoint] = itertools.chain(
+            importlib_metadata.entry_points(group="pdm"),
+            importlib_metadata.entry_points(group="pdm.plugin"),
+        )
+        for plugin in entry_points:
             try:
                 plugin.load()(self)
             except Exception as e:

tests/test_plugin.py

@@ -38,7 +38,7 @@ def test_plugin_new_command(invoke, mocker, project, core):
     mocker.patch.object(
         importlib_metadata,
         "entry_points",
-        return_value={"pdm": [make_entry_point(new_command)]},
+        return_value=[make_entry_point(new_command)],
     )
     core.init_parser()
     core.load_plugins()
@@ -56,7 +56,7 @@ def test_plugin_replace_command(invoke, mocker, project, core):
     mocker.patch.object(
         importlib_metadata,
         "entry_points",
-        return_value={"pdm": [make_entry_point(replace_command)]},
+        return_value=[make_entry_point(replace_command)],
     )
     core.init_parser()
     core.load_plugins()
@@ -72,9 +72,7 @@ def test_load_multiple_plugings(invoke, mocker, core):
     mocker.patch.object(
         importlib_metadata,
         "entry_points",
-        return_value={
-            "pdm": [make_entry_point(new_command), make_entry_point(add_new_config)]
-        },
+        return_value=[make_entry_point(new_command), make_entry_point(add_new_config)],
     )
     core.init_parser()
     core.load_plugins()
@@ -87,13 +85,15 @@ def test_load_multiple_plugings(invoke, mocker, core):
 
 
 def test_old_entry_point_compatibility(invoke, mocker, core):
+    def get_entry_points(group):
+        if group == "pdm":
+            return [make_entry_point(new_command)]
+        if group == "pdm.plugin":
+            return [make_entry_point(add_new_config)]
+        return []
+
     mocker.patch.object(
-        importlib_metadata,
-        "entry_points",
-        return_value={
-            "pdm": [make_entry_point(new_command)],
-            "pdm.plugin": [make_entry_point(add_new_config)],
-        },
+        importlib_metadata, "entry_points", side_effect=get_entry_points
     )
     core.init_parser()
     core.load_plugins()