1 files changed, 104 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/class/params-dflt-meth-args-unmapped.js b/js/src/tests/test262/language/statements/class/params-dflt-meth-args-unmapped.js
new file mode 100644
index 0000000000..e38673c6b5
--- /dev/null
+++ b/js/src/tests/test262/language/statements/class/params-dflt-meth-args-unmapped.js
@@ -0,0 +1,104 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: Referencing the arguments object from a default parameter (class expression method)
+esid: sec-runtime-semantics-bindingclassdeclarationevaluation
+es6id: 14.5.15
+features: [default-parameters]
+info: |
+    ClassDeclaration : class BindingIdentifier ClassTail
+
+    1. Let className be StringValue of BindingIdentifier.
+    2. Let value be the result of ClassDefinitionEvaluation of ClassTail with
+       argument className.
+    [...]
+
+    14.5.14 Runtime Semantics: ClassDefinitionEvaluation
+
+    21. For each ClassElement m in order from methods
+        a. If IsStatic of m is false, then
+           i. Let status be the result of performing
+              PropertyDefinitionEvaluation for m with arguments proto and
+              false.
+        [...]
+
+    14.3.8 Runtime Semantics: DefineMethod
+
+    MethodDefinition : PropertyName ( StrictFormalParameters ) { FunctionBody }
+
+    [...]
+    6. Let closure be FunctionCreate(kind, StrictFormalParameters, FunctionBody,
+       scope, strict). If functionPrototype was passed as a parameter then pass its
+       value as the functionPrototype optional argument of FunctionCreate.
+    [...]
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+    14.1.19 Runtime Semantics: IteratorBindingInitialization
+
+    FormalsList : FormalsList , FormalParameter
+
+    1. Let status be the result of performing IteratorBindingInitialization for
+       FormalsList using iteratorRecord and environment as the arguments.
+    2. ReturnIfAbrupt(status).
+    3. Return the result of performing IteratorBindingInitialization for
+       FormalParameter using iteratorRecord and environment as the arguments. 
+---*/
+
+var callCount = 0;
+class C {
+  method(x, _ = 0) {
+    assert.sameValue(x, undefined, 'parameter binding value (initial)');
+    assert.sameValue(
+      arguments[0], undefined, 'arguments property value (initial)'
+    );
+
+    arguments[0] = 1;
+
+    assert.sameValue(
+      x, undefined, 'parameter binding value (after arguments modification)'
+    );
+    assert.sameValue(
+      arguments[0], 1, 'arguments property value (after arguments modification)'
+    );
+
+    x = 2;
+
+    assert.sameValue(
+      x, 2, 'parameter binding value (after parameter binding modification)'
+    );
+    assert.sameValue(
+      arguments[0],
+      1,
+      'arguments property value (after parameter binding modification)'
+    );
+    callCount = callCount + 1;
+  }
+}
+
+C.prototype.method();
+
+assert.sameValue(callCount, 1, 'method invoked exactly once');
+
+reportCompare(0, 0);