Fixed a bug that led to a false negative when using a non-TypedDict b…

…ase class within a TypedDict class statement. This addresses #5937.

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

@@ -15935,13 +15935,6 @@ export function createTypeEvaluator(importLookup: ImportLookup, evaluatorOptions
  // a TypedDict, it is considered a TypedDict.
  if (ClassType.isBuiltIn(argType, 'TypedDict') || ClassType.isTypedDictClass(argType)) {
  classType.details.flags |= ClassTypeFlags.TypedDictClass;
- } else if (ClassType.isTypedDictClass(classType) && !ClassType.isTypedDictClass(argType)) {
- // Exempt Generic from this test. As of Python 3.11, generic TypedDict
- // classes are supported.
- if (!isInstantiableClass(argType) || !ClassType.isBuiltIn(argType, 'Generic')) {
- // TypedDict classes must derive only from other TypedDict classes.
- addError(Localizer.Diagnostic.typedDictBaseClass(), arg);
- }
  }
 
  // Validate that the class isn't deriving from itself, creating a
@@ -16385,6 +16378,27 @@ export function createTypeEvaluator(importLookup: ImportLookup, evaluatorOptions
 
  // Synthesize TypedDict methods.
  if (ClassType.isTypedDictClass(classType)) {
+ // TypedDict classes must derive only from other TypedDict classes.
+ let foundInvalidBaseClass = false;
+ const diag = new DiagnosticAddendum();
+
+ classType.details.baseClasses.forEach((baseClass) => {
+ if (
+ isClass(baseClass) &&
+ !ClassType.isTypedDictClass(baseClass) &&
+ !ClassType.isBuiltIn(baseClass, ['_TypedDict', 'Generic'])
+ ) {
+ foundInvalidBaseClass = true;
+ diag.addMessage(
+ Localizer.DiagnosticAddendum.typedDictBaseClass().format({ type: baseClass.details.name })
+ );
+ }
+ });
+
+ if (foundInvalidBaseClass) {
+ addError(Localizer.Diagnostic.typedDictBaseClass() + diag.getString(), node.name);
+ }
+
  synthesizeTypedDictClassMethods(
  evaluatorInterface,
  node,

packages/pyright-internal/src/localization/localize.ts

@@ -1353,6 +1353,8 @@ export namespace Localizer {
  new ParameterizedString<{ type: string; name: string }>(
  getRawString('DiagnosticAddendum.typeConstrainedTypeVar')
  );
+ export const typedDictBaseClass = () =>
+ new ParameterizedString<{ type: string }>(getRawString('DiagnosticAddendum.typedDictBaseClass'));
  export const typedDictFieldMissing = () =>
  new ParameterizedString<{ name: string; type: string }>(
  getRawString('DiagnosticAddendum.typedDictFieldMissing')

packages/pyright-internal/src/localization/package.nls.en-us.json

@@ -680,6 +680,7 @@
  "typeAssignmentMismatch": "Type \"{sourceType}\" cannot be assigned to type \"{destType}\"",
  "typeBound": "Type \"{sourceType}\" is incompatible with bound type \"{destType}\" for type variable \"{name}\"",
  "typeConstrainedTypeVar": "Type \"{type}\" is incompatible with constrained type variable \"{name}\"",
+ "typedDictBaseClass": "Class \"{type}\" is not a TypedDict",
  "typedDictFieldMissing": "\"{name}\" is missing from \"{type}\"",
  "typedDictFieldNotReadOnly": "\"{name}\" is not read-only in \"{type}\"",
  "typedDictFieldNotRequired": "\"{name}\" is not required in \"{type}\"",

packages/pyright-internal/src/tests/samples/typedDict1.py

@@ -62,3 +62,9 @@ class NotATD:
 # base classes shouldn't be allowed for TD classes.
 class TD6(TD3, NotATD):
  pass
+
+
+# This should generate an error because non-TypeDict
+# base classes shouldn't be allowed for TD classes.
+class TD7(NotATD, TypedDict):
+ pass

packages/pyright-internal/src/tests/typeEvaluator2.test.ts

@@ -1320,7 +1320,7 @@ test('Protocol44', () => {
 test('TypedDict1', () => {
  const analysisResults = TestUtils.typeAnalyzeSampleFiles(['typedDict1.py']);
 
- TestUtils.validateResults(analysisResults, 6);
+ TestUtils.validateResults(analysisResults, 7);
 });
 
 test('TypedDict2', () => {