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.
microsoft · Sep 13, 2023 · de64cae · de64cae
1 parent 08bf803
commit de64cae
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Showing 5 changed files with 31 additions and 8 deletions.
diff --git a/packages/pyright-internal/src/analyzer/typeEvaluator.ts b/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,

diff --git a/packages/pyright-internal/src/localization/localize.ts b/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')

diff --git a/packages/pyright-internal/src/localization/package.nls.en-us.json b/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}\"",

diff --git a/packages/pyright-internal/src/tests/samples/typedDict1.py b/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
diff --git a/packages/pyright-internal/src/tests/typeEvaluator2.test.ts b/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', () => {