[red-knot] Two gradual equivalent fully static types are also equival…

…ent (astral-sh#15579)

crates/red_knot_python_semantic/src/types/property_tests.rs

@@ -351,6 +351,20 @@ mod stable {
             s.is_fully_static(db) && t.is_fully_static(db)
             => s.is_subtype_of(db, union(db, [s, t])) && t.is_subtype_of(db, union(db, [s, t]))
     );
+
+    // A fully static type does not have any materializations.
+    // Thus, two equivalent (fully static) types are also gradual equivalent.
+    type_property_test!(
+        two_equivalent_types_are_also_gradual_equivalent, db,
+        forall types s, t. s.is_equivalent_to(db, t) => s.is_gradual_equivalent_to(db, t)
+    );
+
+    // Two gradual equivalent fully static types are also equivalent.
+    type_property_test!(
+        two_gradual_equivalent_fully_static_types_are_also_equivalent, db,
+        forall types s, t.
+            s.is_fully_static(db) && s.is_gradual_equivalent_to(db, t) => s.is_equivalent_to(db, t)
+    );
 }
 
 /// This module contains property tests that currently lead to many false positives.
@@ -440,11 +454,4 @@ mod flaky {
                 .permutations(2)
                 .all(|vec_of_unions| vec_of_unions[0].is_equivalent_to(db, vec_of_unions[1]))
     );
-
-    // A fully static type does not have any materializations.
-    // Thus, two equivalent (fully static) types are also gradual equivalent.
-    type_property_test!(
-        two_equivalent_types_are_also_gradual_equivalent, db,
-        forall types s, t. s.is_equivalent_to(db, t) => s.is_gradual_equivalent_to(db, t)
-    );
 }