Replace use of pkg_resources with importlib.metadata

Use iter_entry_points() workaround until Python 3.9 support is dropped

grizzly/args.py

@@ -18,8 +18,7 @@
 from FTB.ProgramConfiguration import ProgramConfiguration
 
 from .common.fuzzmanager import FM_CONFIG
-from .common.plugins import scan as scan_plugins
-from .common.plugins import scan_target_assets
+from .common.plugins import scan_plugins, scan_target_assets
 from .common.utils import DEFAULT_TIME_LIMIT, TIMEOUT_DELAY, package_version
 
 

grizzly/common/plugins.py

@@ -4,9 +4,13 @@
 from logging import getLogger
 from typing import Any, Dict, List, Tuple
 
-from pkg_resources import iter_entry_points
+try:
+    from pkg_resources import iter_entry_points
+except ImportError:
+    from .utils import iter_entry_points  # type: ignore
 
-__all__ = ("load", "scan", "PluginLoadError")
+
+__all__ = ("load_plugin", "scan_plugins", "PluginLoadError")
 
 
 LOG = getLogger(__name__)
@@ -16,7 +20,7 @@ class PluginLoadError(Exception):
     """Raised if loading a plug-in fails"""
 
 
-def load(name: str, group: str, base_type: type) -> Any:
+def load_plugin(name: str, group: str, base_type: type) -> Any:
     """Load a plug-in.
 
     Args:
@@ -30,8 +34,8 @@ def load(name: str, group: str, base_type: type) -> Any:
     assert isinstance(base_type, type)
     for entry in iter_entry_points(group):
         if entry.name == name:
-            LOG.debug("loading %r (%s)", name, base_type.__name__)
             plugin = entry.load()
+            LOG.debug("loading %r (%s)", name, base_type.__name__)
             break
     else:
         raise PluginLoadError(f"{name!r} not found in {group!r}")
@@ -40,7 +44,7 @@ def load(name: str, group: str, base_type: type) -> Any:
     return plugin
 
 
-def scan(group: str) -> List[str]:
+def scan_plugins(group: str) -> List[str]:
     """Scan for installed plug-ins.
 
     Args:
@@ -49,7 +53,7 @@ def scan(group: str) -> List[str]:
     Returns:
         Names of installed entry points.
     """
-    found = []
+    found: List[str] = []
     LOG.debug("scanning %r", group)
     for entry in iter_entry_points(group):
         if entry.name in found:
@@ -68,7 +72,7 @@ def scan_target_assets() -> Dict[str, Tuple[str, ...]]:
     Returns:
         Name of target and list of supported assets.
     """
-    assets = {}
+    assets: Dict[str, Tuple[str, ...]] = {}
     for entry in iter_entry_points("grizzly_targets"):
         assets[entry.name] = entry.load().SUPPORTED_ASSETS
     return assets

grizzly/common/test_plugins.py

@@ -1,11 +1,12 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
-from pkg_resources import EntryPoint
+from importlib.metadata import EntryPoint
+
 from pytest import raises
 
 from ..target import Target
-from .plugins import PluginLoadError, load, scan, scan_target_assets
+from .plugins import PluginLoadError, load_plugin, scan_plugins, scan_target_assets
 
 
 class FakeType1:
@@ -19,22 +20,23 @@ class FakeType2:
 def test_load_01(mocker):
     """test load() - nothing to load"""
     mocker.patch(
-        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=[]
+        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=()
     )
     with raises(PluginLoadError, match="'test-name' not found in 'test-group'"):
-        load("test-name", "test-group", FakeType1)
+        load_plugin("test-name", "test-group", FakeType1)
 
 
 def test_load_02(mocker):
     """test load() - successful load"""
-    # Note: Mock.name cannot be set via the constructor so spec_set cannot be used
     entry = mocker.Mock(spec=EntryPoint)
     entry.name = "test-name"
     entry.load.return_value = FakeType1
     mocker.patch(
-        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=[entry]
+        "grizzly.common.plugins.iter_entry_points",
+        autospec=True,
+        return_value=(entry,),
     )
-    assert load("test-name", "test-group", FakeType1)
+    assert load_plugin("test-name", "test-group", FakeType1)
 
 
 def test_load_03(mocker):
@@ -43,18 +45,20 @@ def test_load_03(mocker):
     entry.name = "test-name"
     entry.load.return_value = FakeType1
     mocker.patch(
-        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=[entry]
+        "grizzly.common.plugins.iter_entry_points",
+        autospec=True,
+        return_value=(entry,),
     )
     with raises(PluginLoadError, match="'test-name' doesn't inherit from FakeType2"):
-        load("test-name", "test-group", FakeType2)
+        load_plugin("test-name", "test-group", FakeType2)
 
 
 def test_scan_01(mocker):
     """test scan() - no entries found"""
     mocker.patch(
-        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=[]
+        "grizzly.common.plugins.iter_entry_points", autospec=True, return_value=()
     )
-    assert not scan("test_group")
+    assert not scan_plugins("test_group")
 
 
 def test_scan_02(mocker):
@@ -64,10 +68,10 @@ def test_scan_02(mocker):
     mocker.patch(
         "grizzly.common.plugins.iter_entry_points",
         autospec=True,
-        return_value=[entry, entry],
+        return_value=(entry, entry),
     )
     with raises(PluginLoadError, match="Duplicate entry 'test_entry' in 'test_group'"):
-        scan("test_group")
+        scan_plugins("test_group")
 
 
 def test_scan_03(mocker):
@@ -77,26 +81,26 @@ def test_scan_03(mocker):
     mocker.patch(
         "grizzly.common.plugins.iter_entry_points",
         autospec=True,
-        return_value=[entry],
+        return_value=(entry,),
     )
-    assert "test-name" in scan("test_group")
+    assert "test-name" in scan_plugins("test_group")
 
 
 def test_scan_target_assets_01(mocker):
     """test scan_target_assets() - success"""
     targ1 = mocker.Mock(spec=EntryPoint)
     targ1.name = "t1"
-    targ1.load.return_value = mocker.Mock(spec_set=Target, SUPPORTED_ASSETS=None)
+    targ1.load.return_value = mocker.Mock(spec_set=Target, SUPPORTED_ASSETS=())
     targ2 = mocker.Mock(spec=EntryPoint)
     targ2.name = "t2"
     targ2.load.return_value = mocker.Mock(spec_set=Target, SUPPORTED_ASSETS=("a", "B"))
     mocker.patch(
         "grizzly.common.plugins.iter_entry_points",
         autospec=True,
-        return_value=[targ1, targ2],
+        return_value=(targ1, targ2),
     )
     assets = scan_target_assets()
     assert "t1" in assets
-    assert assets["t1"] is None
+    assert not assets["t1"]
     assert "t2" in assets
     assert "B" in assets["t2"]

grizzly/common/utils.py

@@ -1,13 +1,14 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
+import sys  # mypy looks for `sys.version_info`
 from enum import IntEnum, unique
-from importlib.metadata import PackageNotFoundError, version
+from importlib.metadata import EntryPoint, PackageNotFoundError, entry_points, version
 from logging import DEBUG, basicConfig, getLogger
 from os import getenv
 from pathlib import Path
 from tempfile import gettempdir
-from typing import Any, Iterable, Optional, Tuple, Union
+from typing import Any, Generator, Iterable, Optional, Tuple, Union
 
 __all__ = (
     "ConfigError",
@@ -17,6 +18,7 @@
     "Exit",
     "grz_tmp",
     "HARNESS_FILE",
+    "iter_entry_points",
     "package_version",
     "time_limits",
     "TIMEOUT_DELAY",
@@ -105,6 +107,25 @@ def display_time_limits(time_limit: int, timeout: int, no_harness: bool) -> None
         LOG.warning("TIMEOUT DISABLED, not recommended for automation")
 
 
+def iter_entry_points(
+    group: str,
+) -> Generator[EntryPoint, None, None]:  # pragma: no cover
+    """Compatibility wrapper code for importlib.metadata.entry_points()
+
+    Args:
+        group: See entry_points().
+
+    Yields:
+        EntryPoint
+    """
+    # TODO: remove this function when support for Python 3.9 is dropped
+    assert group
+    if sys.version_info >= (3, 10):
+        yield from entry_points().select(group=group)
+    else:
+        raise AssertionError("Unsupported Python version")
+
+
 def package_version(name: str, default: str = "unknown") -> str:
     """Get version of an installed package.
 

grizzly/main.py

@@ -9,7 +9,7 @@
 from sapphire import CertificateBundle, Sapphire
 
 from .adapter import Adapter
-from .common.plugins import load as load_plugin
+from .common.plugins import load_plugin
 from .common.reporter import (
     FailedLaunchReporter,
     FilesystemReporter,

grizzly/reduce/core.py

@@ -18,7 +18,7 @@
 from sapphire import CertificateBundle, Sapphire
 
 from ..common.fuzzmanager import CrashEntry
-from ..common.plugins import load as load_plugin
+from ..common.plugins import load_plugin
 from ..common.reporter import (
     FailedLaunchReporter,
     FilesystemReporter,

grizzly/reduce/strategies/__init__.py

@@ -30,11 +30,14 @@
     cast,
 )
 
-from pkg_resources import iter_entry_points
-
 from ...common.storage import TestCase
 from ...common.utils import grz_tmp
 
+try:
+    from pkg_resources import iter_entry_points
+except ImportError:
+    from ...common.utils import iter_entry_points  # type: ignore
+
 LOG = getLogger(__name__)
 
 

grizzly/reduce/test_strategies.py

@@ -82,11 +82,10 @@ class _BadStrategy:
         def load(cls):
             raise RuntimeError("oops")
 
-    def entries(_):
-        yield _BadStrategy
-        yield _GoodStrategy
-
-    mocker.patch("grizzly.reduce.strategies.iter_entry_points", side_effect=entries)
+    mocker.patch(
+        "grizzly.reduce.strategies.iter_entry_points",
+        return_value=(_BadStrategy, _GoodStrategy),
+    )
     mocker.patch("grizzly.reduce.strategies.DEFAULT_STRATEGIES", new=("good",))
     result = _load_strategies()
     assert result == {"good": _GoodStrategy}

grizzly/replay/replay.py

@@ -13,7 +13,7 @@
 
 from sapphire import CertificateBundle, Sapphire, ServerMap
 
-from ..common.plugins import load as load_plugin
+from ..common.plugins import load_plugin
 from ..common.report import Report
 from ..common.reporter import (
     FailedLaunchReporter,