Add more tests, fix new style classes

Author: ilevkivskyi

mypy/semanal.py

@@ -1992,7 +1992,7 @@ def analyze_class(self, defn: ClassDef) -> None:
         if any(has_placeholder(tvd) for tvd in tvar_defs):
             # Some type variable bounds or values are not ready, we need
             # to re-analyze this class.
-            self.defer()
+            self.defer(force_progress=tvar_defs != defn.type_vars)
 
         self.analyze_class_keywords(defn)
         bases_result = self.analyze_base_classes(bases)

test-data/unit/check-python313.test

@@ -338,6 +338,52 @@ class Bar[U]:
     def foo(data: U, cond: bool) -> Result[U, str]:
         return Ok(data) if cond else Err("Error")
 
+[case testRecursiveTypeVarDefaultBasicNewStyle]
+class C[T: C = C]:
+    pass
+
+c: C
+reveal_type(c)  # N: Revealed type is "__main__.C[__main__.C[Any]]"
+
+[case testRecursiveTypeVarDefaultMutualNewStyle]
+class C[T = D]:
+    pass
+
+class D[S = C]:
+    pass
+
+c: C
+d: D
+reveal_type(c)  # N: Revealed type is "__main__.C[__main__.D[Any]]"
+reveal_type(d)  # N: Revealed type is "__main__.D[__main__.C[Any]]"
+
+[case testNonRecursiveSimpleTypeVarDefaultNewStyle]
+class Child[S = Parent]: ...
+
+class Parent[T = int]: ...
+
+reveal_type(Child())  # N: Revealed type is "__main__.Child[__main__.Parent[builtins.int]]"
+
+[case testRecursiveTypeVarDefaultClassAndAliasNewStyle]
+class Trait[T = Pattern]:
+    pass
+
+class Pattern1(Trait):
+    pass
+class Pattern2(Trait):
+    pass
+
+type Pattern = Pattern1 | Pattern2
+
+reveal_type(Trait())  # N: Revealed type is "__main__.Trait[__main__.Pattern1 | __main__.Pattern2]"
+[builtins fixtures/tuple.pyi]
+
+[case testRecursiveTypeVarDefaultOnlyAliasNewStyle]
+type A[T = A] = list[T]
+a: A
+reveal_type(a)  # N: Revealed type is "builtins.list[builtins.list[Any]]"
+[builtins fixtures/tuple.pyi]
+
 [case testRecursiveAliasTypeVarDefaultNewStyle]
 type A[T = A] = int
 a: A