Fix get_plugins() bug

docs/source/package_definition.rst

@@ -748,14 +748,14 @@ the data type, and includes a code snippet.
       name = "maya_utils"
 
 .. py:attribute:: plugin_for
-   :type: str
+   :type: list[str]
 
    Provided if this package is a plugin of another package. For example, this might be a maya plugin.
    This is useful when using the :ref:`rez-plugins` command. Also, see :attr:`has_plugins`.
 
    .. code-block:: python
 
-      plugin_for = "maya"
+      plugin_for = ["maya"]
 
 .. py:function:: post_commands() -> None
 

src/rez/package_search.py

@@ -12,6 +12,7 @@
 
 import fnmatch
 from collections import defaultdict
+from typing import List
 import sys
 
 from rez.packages import iter_package_families, iter_packages, get_latest_package
@@ -126,7 +127,7 @@ def get_reverse_dependency_tree(package_name, depth=None, paths=None,
     return pkgs_list, g
 
 
-def get_plugins(package_name, paths=None):
+def get_plugins(package_name: str, paths: List[str] = None) -> List[str]:
     """Find packages that are plugins of the given package.
 
     Args:
@@ -152,7 +153,7 @@ def get_plugins(package_name, paths=None):
             continue  # not a plugin of itself
 
         plugin_pkg = get_latest_package(package_name_, paths=paths)
-        if not plugin_pkg.plugin_for:
+        if not plugin_pkg or not plugin_pkg.plugin_for:
             continue
         for plugin_for in plugin_pkg.plugin_for:
             if plugin_for == pkg.name:

src/rez/tests/test_package_search.py

@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright Contributors to the Rez Project
+
+
+"""
+Test cases for package_search.py (package searching)
+"""
+import os
+
+from rez.package_maker import make_package
+from rez.package_search import get_plugins
+from rez.tests.util import TestBase, TempdirMixin
+
+
+class TestPackageSearch(TestBase, TempdirMixin):
+    """Class for a package searching test case"""
+    @classmethod
+    def setUpClass(cls):
+        TempdirMixin.setUpClass()
+
+        cls.settings = dict(
+            packages_path=[
+                cls.root
+            ]
+        )
+
+    @classmethod
+    def tearDownClass(cls):
+        TempdirMixin.tearDownClass()
+
+    def test_not_has_plugins(self):
+        """Ensure empty list is returned when has_plugins is False."""
+
+        with make_package('foo', self.root) as pkg:
+            pkg.has_plugins = False
+
+        plugins = get_plugins('foo')
+        self.assertEqual(plugins, [])
+
+    def test_get_plugins(self):
+        """Ensure package plugins are obtained as expected."""
+
+        with make_package('foo', self.root) as pkg:
+            pkg.has_plugins = True
+
+        with make_package('foo_plugin', self.root) as pkg:
+            pkg.plugin_for = ["foo"]
+
+        plugins = get_plugins('foo')
+        self.assertEqual(plugins, ['foo_plugin'])
+
+    def test_get_plugins_empty_folder(self):
+        """When an empty folder is present, plugins should still be valid."""
+
+        with make_package('foo', self.root) as pkg:
+            pkg.has_plugins = True
+
+        with make_package('foo_plugin', self.root) as pkg:
+            pkg.plugin_for = ["foo"]
+
+        os.mkdir(os.path.join(self.root, 'broken_pkg'))
+
+        plugins = get_plugins('foo')
+        self.assertEqual(plugins, ['foo_plugin'])