Added missing check for out-of-bound index accesses for named tuple i…

…nstances. This addresses #7196. (#7207)
microsoft · Feb 4, 2024 · 626f655 · 626f655
1 parent e2fab53
commit 626f655
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Showing 3 changed files with 10 additions and 6 deletions.
diff --git a/packages/pyright-internal/src/analyzer/checker.ts b/packages/pyright-internal/src/analyzer/checker.ts
@@ -144,6 +144,7 @@ import {
     getDeclaredGeneratorReturnType,
     getGeneratorTypeArgs,
     getProtocolSymbolsRecursive,
+    getSpecializedTupleType,
     getTypeVarArgumentsRecursive,
     getTypeVarScopeId,
     isLiteralType,
@@ -1242,13 +1243,15 @@ export class Checker extends ParseTreeWalker {
         const baseType = this._evaluator.getType(node.baseExpression);
         if (baseType) {
             doForEachSubtype(baseType, (subtype) => {
+                const tupleType = getSpecializedTupleType(subtype);
+
                 if (
                     isClassInstance(subtype) &&
-                    subtype.tupleTypeArguments &&
-                    !isUnboundedTupleClass(subtype) &&
-                    !this._evaluator.isTypeSubsumedByOtherType(subtype, baseType, /* allowAnyToSubsume */ false)
+                    tupleType?.tupleTypeArguments &&
+                    !isUnboundedTupleClass(tupleType) &&
+                    !this._evaluator.isTypeSubsumedByOtherType(tupleType, baseType, /* allowAnyToSubsume */ false)
                 ) {
-                    const tupleLength = subtype.tupleTypeArguments.length;
+                    const tupleLength = tupleType.tupleTypeArguments.length;
 
                     if (
                         node.items.length === 1 &&

diff --git a/packages/pyright-internal/src/tests/samples/tuple1.py b/packages/pyright-internal/src/tests/samples/tuple1.py
@@ -174,9 +174,10 @@ def func13(
 
     v10 = d[0]
 
+    # This should generate an error.
     v11 = d[1]
 
-    # This should generate an error.
+    # This should generate two errors.
     v12 = d[2]
 
     v13: tuple[()] = ()

diff --git a/packages/pyright-internal/src/tests/typeEvaluator1.test.ts b/packages/pyright-internal/src/tests/typeEvaluator1.test.ts
@@ -1270,7 +1270,7 @@ test('Optional2', () => {
 test('Tuple1', () => {
     const analysisResults = TestUtils.typeAnalyzeSampleFiles(['tuple1.py']);
 
-    TestUtils.validateResults(analysisResults, 22);
+    TestUtils.validateResults(analysisResults, 24);
 });
 
 test('Tuple2', () => {