Revert "Revert "fix reportUninitializedInstanceVariable false posit…

…ive on `NamedTuple` (new bug in upstream)" since it has now been fixed upstream"

This reverts commit 9f80bab.

packages/pyright-internal/src/analyzer/checker.ts

@@ -5232,13 +5232,19 @@ export class Checker extends ParseTreeWalker {
             if (parentSymbol) {
                 return;
             }
-
-            // Report the variable as uninitialized only on the first decl.
-            this._evaluator.addDiagnostic(
-                DiagnosticRule.reportUninitializedInstanceVariable,
-                LocMessage.uninitializedInstanceVariable().format({ name: name }),
-                decls[0].node
-            );
+            if (
+                !classType.details.baseClasses.some(
+                    (baseClass) =>
+                        baseClass.category === TypeCategory.Class && baseClass.details.fullName === 'typing.NamedTuple'
+                )
+            ) {
+                // Report the variable as uninitialized only on the first decl.
+                this._evaluator.addDiagnostic(
+                    DiagnosticRule.reportUninitializedInstanceVariable,
+                    LocMessage.uninitializedInstanceVariable().format({ name: name }),
+                    decls[0].node
+                );
+            }
         });
 
         // See if there are any variables from abstract base classes

packages/pyright-internal/src/tests/samples/uninitializedVariableBased.py

@@ -0,0 +1,7 @@
+from typing import NamedTuple
+
+class Foo(NamedTuple):
+    a: int # no error
+
+class Bar:
+    b: str # error

packages/pyright-internal/src/tests/typeEvaluatorBased.test.ts

@@ -102,3 +102,12 @@ test('subscript context manager types on 3.8', () => {
         ],
     });
 });
+
+test('no reportUninitializedInstanceVariable on NamedTuple', () => {
+    const configOptions = new ConfigOptions(Uri.empty());
+    configOptions.diagnosticRuleSet.reportUninitializedInstanceVariable = 'error';
+    const analysisResults = typeAnalyzeSampleFiles(['uninitializedVariableBased.py'], configOptions);
+    validateResultsButBased(analysisResults, {
+        errors: [{ code: DiagnosticRule.reportUninitializedInstanceVariable, line: 6 }],
+    });
+});