tests: add basic entry_point_plugins tests

I needed to further adjust the files lookup to ignore distributions that were
not found.

errbot/utils.py

@@ -211,7 +211,17 @@ def entry_point_plugins(group):
     for entry_point in entry_points:
         module_name = entry_point.module
         file_name = module_name.replace(".", "/") + ".py"
-        for f in entry_point.dist.files:
+        try:
+            files = entry_point.dist.files
+        except AttributeError:
+            # workaround to support python 3.9 and older
+            try:
+                files = importlib.metadata.distribution(entry_point.name).files
+            except importlib.metadata.PackageNotFoundError:
+                # entrypoint is not a distribution, so let's skip looking for files
+                continue
+
+        for f in files:
             if file_name == str(f):
                 parent = str(pathlib.Path(f).resolve().parent)
                 paths.append(f"{parent}/{module_name}")

tests/utils_test.py

@@ -1,7 +1,6 @@
 # coding=utf-8
 import logging
 import sys
-
 from datetime import timedelta
 
 import pytest
@@ -11,7 +10,12 @@
 from errbot.bootstrap import CORE_STORAGE, bot_config_defaults
 from errbot.storage import StoreMixin
 from errbot.storage.base import StoragePluginBase
-from errbot.utils import version2tuple, format_timedelta, split_string_after
+from errbot.utils import (
+    entry_point_plugins,
+    format_timedelta,
+    split_string_after,
+    version2tuple,
+)
 
 log = logging.getLogger(__name__)
 
@@ -103,3 +107,17 @@ def test_split_string_after_returns_two_chunks_when_chunksize_equals_half_length
     splitter = split_string_after(str_, int(len(str_) / 2))
     split = [chunk for chunk in splitter]
     assert ["foobar2000", "foobar2000"] == split
+
+
+def test_entry_point_plugins_no_groups():
+    result = entry_point_plugins("does_not_exist")
+    assert [] == result
+
+
+def test_entry_point_plugins_valid_groups():
+    results = entry_point_plugins("console_scripts")
+    match = False
+    for result in results:
+        if result.endswith("errbot/errbot.cli"):
+            match = True
+    assert match