PY-83700 Support implicit type aliases at class level

(cherry picked from commit efaf7fb9ae413370f18429859c05f114e6cf4677)

IJ-CR-176451

(cherry picked from commit 71bdaa9858d8092ad6201ce773c8b5d4117b86f5)

GitOrigin-RevId: be66d9701e23760f035a3f5f3db822cfcc8630bb

Author: east825

python/python-psi-impl/src/com/jetbrains/python/psi/impl/stubs/PyTypingAliasStubType.java

@@ -25,6 +25,7 @@
 import com.jetbrains.python.PyElementTypes;
 import com.jetbrains.python.PyTokenTypes;
 import com.jetbrains.python.ast.impl.PyUtilCore;
+import com.jetbrains.python.codeInsight.dataflow.scope.ScopeUtil;
 import com.jetbrains.python.codeInsight.typing.PyTypingTypeProvider;
 import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.resolve.PyResolveUtil;
@@ -68,7 +69,7 @@ public final class PyTypingAliasStubType extends CustomTargetExpressionStubType<
   }
 
   private static @Nullable PyExpression getAssignedValueIfTypeAliasLike(@NotNull PyTargetExpression target, boolean forStubCreation) {
-    if (!PyUtil.isTopLevel(target) || !looksLikeTypeAliasTarget(target)) {
+    if (!(PyUtil.isTopLevel(target) || ScopeUtil.getScopeOwner(target) instanceof PyClass) || !looksLikeTypeAliasTarget(target)) {
       return null;
     }
     final PyExpression value = target.findAssignedValue();

python/testData/inspections/PyTypeHintsInspection/ImplicitTypeAliasAtClassLevelMultiFile/a.py

@@ -0,0 +1,4 @@
+from lib import Baz
+
+
+def bar(baz: Baz.SOME_TYPE) -> None: ...

python/testData/inspections/PyTypeHintsInspection/ImplicitTypeAliasAtClassLevelMultiFile/lib.py

@@ -0,0 +1,10 @@
+from typing import Generic, TypeVar
+
+T1 = TypeVar("T1")
+
+
+class Foo(Generic[T1]): ...
+
+
+class Baz:
+    SOME_TYPE = Foo[int]

python/testSrc/com/jetbrains/python/inspections/PyTypeHintsInspectionTest.java

@@ -2957,6 +2957,11 @@ public void testImplicitTypeAliasUsingCallableWithNewStyleUnion() {
                    """);
   }
 
+  // PY-83700
+  public void testImplicitTypeAliasAtClassLevelMultiFile() {
+    doMultiFileTest();
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {