Add test for getting matchers from __context__ in matchers.confirm_top

tests/pytests/unit/matchers/test_confirm_top.py

@@ -2,6 +2,7 @@
 
 import salt.config
 import salt.loader
+from tests.support.mock import patch
 
 
 @pytest.fixture
@@ -12,3 +13,17 @@ def matchers(minion_opts):
 def test_sanity(matchers):
     match = matchers["confirm_top.confirm_top"]
     assert match("*", []) is True
+
+
+@pytest.mark.parametrize("in_context", [False, True])
+def test_matchers_from_context(matchers, in_context):
+    match = matchers["confirm_top.confirm_top"]
+    with patch.dict(
+        matchers.pack["__context__"], {"matchers": matchers} if in_context else {}
+    ), patch("salt.loader.matchers", return_value=matchers) as loader_matchers:
+        assert match("*", []) is True
+        assert id(matchers.pack["__context__"]["matchers"]) == id(matchers)
+        if in_context:
+            loader_matchers.assert_not_called()
+        else:
+            loader_matchers.assert_called_once()