1 files changed, 62 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/function/length-dflt.js b/js/src/tests/test262/language/statements/function/length-dflt.js
new file mode 100644
index 0000000000..e778ff2b9f
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+++ b/js/src/tests/test262/language/statements/function/length-dflt.js
@@ -0,0 +1,62 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+es6id: 14.1.6
+description: >
+  Default parameters' effect on function length
+info: |
+  Function length is counted by the non initialized parameters in the left.
+
+  9.2.4 FunctionInitialize (F, kind, ParameterList, Body, Scope)
+
+  [...]
+  2. Let len be the ExpectedArgumentCount of ParameterList.
+  3. Perform ! DefinePropertyOrThrow(F, "length", PropertyDescriptor{[[Value]]:
+     len, [[Writable]]: false, [[Enumerable]]: false, [[Configurable]]: true}).
+  [...]
+
+  FormalsList : FormalParameter
+
+    1. If HasInitializer of FormalParameter is true return 0
+    2. Return 1.
+
+  FormalsList : FormalsList , FormalParameter
+
+    1. Let count be the ExpectedArgumentCount of FormalsList.
+    2. If HasInitializer of FormalsList is true or HasInitializer of
+    FormalParameter is true, return count.
+    3. Return count+1.
+features: [default-parameters]
+includes: [propertyHelper.js]
+---*/
+
+
+function f1(x = 42) {}
+
+assert.sameValue(f1.length, 0, 'FormalsList: x = 42');
+verifyNotEnumerable(f1, 'length');
+verifyNotWritable(f1, 'length');
+verifyConfigurable(f1, 'length');
+
+function f2(x = 42, y) {}
+
+assert.sameValue(f2.length, 0, 'FormalsList: x = 42, y');
+verifyNotEnumerable(f2, 'length');
+verifyNotWritable(f2, 'length');
+verifyConfigurable(f2, 'length');
+
+function f3(x, y = 42) {}
+
+assert.sameValue(f3.length, 1, 'FormalsList: x, y = 42');
+verifyNotEnumerable(f3, 'length');
+verifyNotWritable(f3, 'length');
+verifyConfigurable(f3, 'length');
+
+function f4(x, y = 42, z) {}
+
+assert.sameValue(f4.length, 1, 'FormalsList: x, y = 42, z');
+verifyNotEnumerable(f4, 'length');
+verifyNotWritable(f4, 'length');
+verifyConfigurable(f4, 'length');
+
+reportCompare(0, 0);