Fix in operator inside for statement destructuring

https://bugs.webkit.org/show_bug.cgi?id=247436 rdar://102065296 Reviewed by Alexey Shvayka. Destructing statement should allow `in` operator even in `for...in/of`. * JSTests/stress/destructing-in.js: Added. (shouldBe): * Source/JavaScriptCore/parser/Parser.cpp: (JSC::Parser<LexerType>::parseVariableDeclarationList): Canonical link: https://commits.webkit.org/256497@main
WebKit · Nov 9, 2022 · 598cda6 · 598cda6
1 parent 6a2efe7
commit 598cda6
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Showing 2 changed files with 26 additions and 1 deletion.
diff --git a/JSTests/stress/destructing-in.js b/JSTests/stress/destructing-in.js
@@ -0,0 +1,20 @@
+function shouldBe(actual, expected) {
+    if (actual !== expected)
+        throw new Error('bad value: ' + actual);
+}
+
+for (var { x = 0 in [0] } of [0]) {
+    shouldBe(x, true);
+}
+
+for (var { x = (0 in [0]) } of [0]) {
+    shouldBe(x, true);
+}
+
+for (var { x = 0 in [0] } in [0]) {
+    shouldBe(x, true);
+}
+
+for (var { x = (0 in [0]) } in [0]) {
+    shouldBe(x, true);
+}
diff --git a/Source/JavaScriptCore/parser/Parser.cpp b/Source/JavaScriptCore/parser/Parser.cpp
@@ -952,7 +952,12 @@ template <class TreeBuilder> TreeExpression Parser<LexerType>::parseVariableDecl
             }
         } else {
             lastIdent = nullptr;
-            auto pattern = parseDestructuringPattern(context, destructuringKindFromDeclarationType(declarationType), exportType, nullptr, nullptr, assignmentContext);
+            TreeDestructuringPattern pattern;
+            {
+                bool allowsInOperator = true;
+                SetForScope allowsInScope(m_allowsIn, allowsInOperator);
+                pattern = parseDestructuringPattern(context, destructuringKindFromDeclarationType(declarationType), exportType, nullptr, nullptr, assignmentContext);
+            }
             failIfFalse(pattern, "Cannot parse this destructuring pattern");
             hasInitializer = match(EQUAL);
             failIfTrue(declarationListContext == VarDeclarationContext && !hasInitializer, "Expected an initializer in destructuring variable declaration");