Provide fields' types for typing.NamedTuple(...) inheritors (PY-32240)

python/src/com/jetbrains/python/codeInsight/stdlib/PyNamedTupleTypeProvider.kt

@@ -34,6 +34,11 @@ class PyNamedTupleTypeProvider : PyTypeProviderBase() {
       return fieldTypeForNamedTuple
     }
 
+    val fieldTypeForTypingNTFunctionInheritor = getFieldTypeForTypingNTFunctionInheritor(referenceExpression, context)
+    if (fieldTypeForTypingNTFunctionInheritor != null) {
+      return fieldTypeForTypingNTFunctionInheritor
+    }
+
     val namedTupleTypeForCallee = getNamedTupleTypeForCallee(referenceExpression, context)
     if (namedTupleTypeForCallee != null) {
       return namedTupleTypeForCallee
@@ -90,6 +95,20 @@ class PyNamedTupleTypeProvider : PyTypeProviderBase() {
       return qualifierNTType.fields[referenceExpression.name]?.type
     }
 
+    private fun getFieldTypeForTypingNTFunctionInheritor(referenceExpression: PyReferenceExpression, context: TypeEvalContext): PyType? {
+      val qualifierType = referenceExpression.qualifier?.let { context.getType(it) } as? PyWithAncestors
+      if (qualifierType == null || qualifierType is PyNamedTupleType) return null
+
+      return PyUnionType.union(
+        qualifierType
+          .getAncestorTypes(context)
+          .filterIsInstance<PyNamedTupleType>()
+          .mapNotNull { it.fields[referenceExpression.name] }
+          .map { it.type }
+          .toList()
+      )
+    }
+
     private fun getNamedTupleTypeForCallee(referenceExpression: PyReferenceExpression, context: TypeEvalContext): PyNamedTupleType? {
       if (PyCallExpressionNavigator.getPyCallExpressionByCallee(referenceExpression) == null) return null
 

python/testSrc/com/jetbrains/python/PyTypeTest.java

@@ -2588,6 +2588,17 @@ public class PyTypeTest extends PyTestCase {
     );
   }
 
+  // PY-32240
+  public void testTypingNTFunctionInheritorField() {
+    doTest("str",
+           "from typing import NamedTuple\n" +
+           "\n" +
+           "class A(NamedTuple(\"NT\", [(\"user\", str)])):\n" +
+           "    pass\n" +
+           "    \n" +
+           "expr = A(undefined).user");
+  }
+
   // PY-4351
   public void testCollectionsNTInheritorField() {
     // Seems that this case won't be supported because