Fix missing dependency trigger for sentinel literals

Author: edgarrmondragon

mypy/server/deps.py

@@ -158,6 +158,7 @@ class 'mod.Cls'. This can also refer to an attribute inherited from a
     ParamSpecType,
     PartialType,
     ProperType,
+    SentinelValue,
     TupleType,
     Type,
     TypeAliasType,
@@ -1096,7 +1097,10 @@ def visit_typeddict_type(self, typ: TypedDictType) -> list[str]:
         return triggers
 
     def visit_literal_type(self, typ: LiteralType) -> list[str]:
-        return self.get_type_triggers(typ.fallback)
+        triggers = self.get_type_triggers(typ.fallback)
+        if isinstance(typ.value, SentinelValue):
+            triggers.append(make_trigger(typ.value.fullname))
+        return triggers
 
     def visit_unbound_type(self, typ: UnboundType) -> list[str]:
         return []

test-data/unit/deps-types.test

@@ -1026,3 +1026,14 @@ class P(Protocol):
 <mod.P> -> <m.x>, m, mod.P
 <mod.P[wildcard]> -> <mod.P>
 <mod> -> m
+
+[case testSentinelType]
+from typing_extensions import Sentinel
+
+MISSING = Sentinel("MISSING")
+
+def f(x: MISSING) -> None:
+    pass
+[builtins fixtures/tuple.pyi]
+[out]
+<m.MISSING> -> <m.MISSING>, <m.f>, m, m.f