Make slots work with parallel=true

salt/state.py

@@ -1906,6 +1906,7 @@ def _call_parallel_target(self, name, cdata, low):
         # correctly calculate further down the chain
         utc_start_time = datetime.datetime.utcnow()
 
+        self.format_slots(cdata)
         tag = _gen_tag(low)
         try:
             ret = self.states[cdata["full"]](*cdata["args"], **cdata["kwargs"])

tests/unit/test_state.py

@@ -618,3 +618,31 @@ def test_slot_append(self):
             self.state_obj.format_slots(cdata)
         mock.assert_called_once_with("fun_arg", fun_key="fun_val")
         self.assertEqual(cdata, {"args": ["arg"], "kwargs": {"key": "value1thing~"}})
+
+    # Skip on windows like integration.modules.test_state.StateModuleTest.test_parallel_state_with_long_tag
+    @skipIf(
+        salt.utils.platform.is_windows(),
+        "Skipped until parallel states can be fixed on Windows",
+    )
+    def test_format_slots_parallel(self):
+        """
+        Test if slots work with "parallel: true".
+        """
+        high_data = {
+            "always-changes-and-succeeds": {
+                "test": [
+                    {"changes": True},
+                    {"comment": "__slot__:salt:test.echo(fun_return)"},
+                    {"parallel": True},
+                    "configurable_test_state",
+                    {"order": 10000},
+                ],
+                "__env__": "base",
+                "__sls__": "parallel_slots",
+            }
+        }
+        self.state_obj.jid = "123"
+        res = self.state_obj.call_high(high_data)
+        self.state_obj.jid = None
+        [(_, data)] = res.items()
+        self.assertEqual(data["comment"], "fun_return")