Add m-esr52 at 52.6.0

1 files changed, 1071 insertions, 0 deletions

diff --git a/js/src/tests/ecma_5/Object/defineProperty-setup.js b/js/src/tests/ecma_5/Object/defineProperty-setup.js
new file mode 100644
index 000000000..da6fe8f49
--- /dev/null
+++ b/js/src/tests/ecma_5/Object/defineProperty-setup.js
@@ -0,0 +1,1071 @@
+// |reftest| skip -- not a test.
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+assertEq("defineProperty" in Object, true);
+assertEq(Object.defineProperty.length, 3);
+
+/*
+ * Disable an assertion that is pathologically slow given the exhaustiveness of
+ * these tests.
+ */
+if (typeof enableStackWalkingAssertion === "function")
+  enableStackWalkingAssertion(false);
+
+if (!Object.prototype.toSource)
+{
+  Object.defineProperty(Object.prototype, "toSource",
+  {
+    value: function toSource()
+    {
+      if (this instanceof RegExp)
+      {
+        var v = "new RegExp(" + uneval(this.source);
+        var f = (this.multiline ? "m" : "") +
+                (this.global ? "g" : "") +
+                (this.ignoreCase ? "i" : "");
+        return v + (f ? ", '" + f + "'" : "") + ")";
+      }
+      return JSON.stringify(this);
+    },
+    enumerable: false,
+    configurable: true,
+    writable: true
+  });
+}
+if (!("uneval" in this))
+{
+  Object.defineProperty(this, "uneval",
+  {
+    value: function uneval(v)
+    {
+      if (v === null)
+        return "null";
+      if (typeof v === "object")
+        return v.toSource();
+      if (typeof v === "string")
+      {
+        v = JSON.stringify({v:v});
+        return v.substring(5, v.length - 1);
+      }
+      return "" + v;
+    },
+    enumerable: false,
+    configurable: true,
+    writable: true
+  });
+}
+
+// reimplemented for the benefit of engines which don't have this helper
+function assertEq(v1, v2, m)
+{
+  if (!SameValue(v1, v2))
+  {
+    throw "assertion failed: " +
+          "got " + uneval(v1) + ", expected " + uneval(v2) +
+          (m ? ": " + m : "");
+  }
+}
+
+function SameValue(v1, v2)
+{
+  if (v1 === 0 && v2 === 0)
+    return 1 / v1 === 1 / v2;
+  if (v1 !== v1 && v2 !== v2)
+    return true;
+  return v1 === v2;
+}
+
+function PropertyDescriptor(pd)
+{
+  if (pd)
+    this.update(pd);
+}
+PropertyDescriptor.prototype.update = function update(pd)
+{
+  if ("get" in pd)
+    this.get = pd.get;
+  if ("set" in pd)
+    this.set = pd.set;
+  if ("configurable" in pd)
+    this.configurable = pd.configurable;
+  if ("writable" in pd)
+    this.writable = pd.writable;
+  if ("enumerable" in pd)
+    this.enumerable = pd.enumerable;
+  if ("value" in pd)
+    this.value = pd.value;
+};
+PropertyDescriptor.prototype.convertToDataDescriptor = function convertToDataDescriptor()
+{
+  delete this.get;
+  delete this.set;
+  this.writable = false;
+  this.value = undefined;
+};
+PropertyDescriptor.prototype.convertToAccessorDescriptor = function convertToAccessorDescriptor()
+{
+  delete this.writable;
+  delete this.value;
+  this.get = undefined;
+  this.set = undefined;
+};
+
+function compareDescriptors(d1, d2)
+{
+  if (d1 === undefined)
+  {
+    assertEq(d2, undefined, "non-descriptors");
+    return;
+  }
+  if (d2 === undefined)
+  {
+    assertEq(true, false, "descriptor-equality mismatch: " + uneval(d1) + ", " + uneval(d2));
+    return;
+  }
+
+  var props = ["value", "get", "set", "enumerable", "configurable", "writable"];
+  for (var i = 0, sz = props.length; i < sz; i++)
+  {
+    var p = props[i];
+    assertEq(p in d1, p in d2, p + " different in d1/d2");
+    if (p in d1)
+      assertEq(d1[p], d2[p], p);
+  }
+}
+
+function examine(desc, field, allowDefault)
+{
+  if (field in desc)
+    return desc[field];
+  assertEq(allowDefault, true, "reimplementation error");
+  switch (field)
+  {
+    case "value":
+    case "get":
+    case "set":
+      return undefined;
+    case "writable":
+    case "enumerable":
+    case "configurable":
+      return false;
+    default:
+      assertEq(true, false, "bad field name: " + field);
+  }
+}
+
+function IsAccessorDescriptor(desc)
+{
+  if (!desc)
+    return false;
+  if (!("get" in desc) && !("set" in desc))
+    return false;
+  return true;
+}
+
+function IsDataDescriptor(desc)
+{
+  if (!desc)
+    return false;
+  if (!("value" in desc) && !("writable" in desc))
+    return false;
+  return true;
+}
+
+function IsGenericDescriptor(desc)
+{
+  if (!desc)
+    return false;
+  if (!IsAccessorDescriptor(desc) && !IsDataDescriptor(desc))
+    return true;
+  return false;
+}
+
+
+
+function CustomObject()
+{
+  this.properties = {};
+  this.extensible = true;
+}
+CustomObject.prototype =
+{
+  _reject: function _reject(throwing, msg)
+  {
+    if (throwing)
+      throw new TypeError(msg + "; rejected!");
+    return false;
+  },
+  defineOwnProperty: function defineOwnProperty(propname, desc, throwing)
+  {
+    assertEq(typeof propname, "string", "non-string propname");
+
+    // Step 1.
+    var current = this.properties[propname];
+
+    // Step 2.
+    var extensible = this.extensible;
+
+    // Step 3.
+    if (current === undefined && !extensible)
+      return this._reject(throwing, "object not extensible");
+
+    // Step 4.
+    if (current === undefined && extensible)
+    {
+      var p;
+      // Step 4(a).
+      if (IsGenericDescriptor(desc) || IsDataDescriptor(desc))
+      {
+        p = new PropertyDescriptor();
+        p.value = examine(desc, "value", true);
+        p.writable = examine(desc, "writable", true);
+        p.enumerable = examine(desc, "enumerable", true);
+        p.configurable = examine(desc, "configurable", true);
+      }
+      // Step 4(b).
+      else
+      {
+        p = new PropertyDescriptor();
+        p.get = examine(desc, "get", true);
+        p.set = examine(desc, "set", true);
+        p.enumerable = examine(desc, "enumerable", true);
+        p.configurable = examine(desc, "configurable", true);
+      }
+
+      this.properties[propname] = p;
+
+      // Step 4(c).
+      return true;
+    }
+
+    // Step 5.
+    if (!("value" in desc) && !("get" in desc) && !("set" in desc) &&
+        !("writable" in desc) && !("enumerable" in desc) &&
+        !("configurable" in desc))
+    {
+      return;
+    }
+
+    // Step 6.
+    do
+    {
+      if ("value" in desc)
+      {
+        if (!("value" in current) || !SameValue(desc.value, current.value))
+          break;
+      }
+      if ("get" in desc)
+      {
+        if (!("get" in current) || !SameValue(desc.get, current.get))
+          break;
+      }
+      if ("set" in desc)
+      {
+        if (!("set" in current) || !SameValue(desc.set, current.set))
+          break;
+      }
+      if ("writable" in desc)
+      {
+        if (!("writable" in current) ||
+            !SameValue(desc.writable, current.writable))
+        {
+          break;
+        }
+      }
+      if ("enumerable" in desc)
+      {
+        if (!("enumerable" in current) ||
+            !SameValue(desc.enumerable, current.enumerable))
+        {
+          break;
+        }
+      }
+      if ("configurable" in desc)
+      {
+        if (!("configurable" in current) ||
+            !SameValue(desc.configurable, current.configurable))
+        {
+          break;
+        }
+      }
+
+      // all fields in desc also in current, with the same values
+      return true;
+    }
+    while (false);
+
+    // Step 7.
+    if (!examine(current, "configurable"))
+    {
+      if ("configurable" in desc && examine(desc, "configurable"))
+        return this._reject(throwing, "can't make configurable again");
+      if ("enumerable" in desc &&
+          examine(current, "enumerable") !== examine(desc, "enumerable"))
+      {
+        return this._reject(throwing, "can't change enumerability");
+      }
+    }
+
+    // Step 8.
+    if (IsGenericDescriptor(desc))
+    {
+      // do nothing
+    }
+    // Step 9.
+    else if (IsDataDescriptor(current) !== IsDataDescriptor(desc))
+    {
+      // Step 9(a).
+      if (!examine(current, "configurable"))
+        return this._reject(throwing, "can't change unconfigurable descriptor's type");
+      // Step 9(b).
+      if (IsDataDescriptor(current))
+        current.convertToAccessorDescriptor();
+      // Step 9(c).
+      else
+        current.convertToDataDescriptor();
+    }
+    // Step 10.
+    else if (IsDataDescriptor(current) && IsDataDescriptor(desc))
+    {
+      // Step 10(a)
+      if (!examine(current, "configurable"))
+      {
+        // Step 10(a).i.
+        if (!examine(current, "writable") &&
+            "writable" in desc && examine(desc, "writable"))
+        {
+          return this._reject(throwing, "can't make data property writable again");
+        }
+        // Step 10(a).ii.
+        if (!examine(current, "writable"))
+        {
+          if ("value" in desc &&
+              !SameValue(examine(desc, "value"), examine(current, "value")))
+          {
+            return this._reject(throwing, "can't change value if not writable");
+          }
+        }
+      }
+      // Step 10(b).
+      else
+      {
+        assertEq(examine(current, "configurable"), true,
+                 "spec bug step 10(b)");
+      }
+    }
+    // Step 11.
+    else
+    {
+      assertEq(IsAccessorDescriptor(current) && IsAccessorDescriptor(desc),
+               true,
+               "spec bug");
+
+      // Step 11(a).
+      if (!examine(current, "configurable"))
+      {
+        // Step 11(a).i.
+        if ("set" in desc &&
+            !SameValue(examine(desc, "set"), examine(current, "set")))
+        {
+          return this._reject(throwing, "can't change setter if not configurable");
+        }
+        // Step 11(a).ii.
+        if ("get" in desc &&
+            !SameValue(examine(desc, "get"), examine(current, "get")))
+        {
+          return this._reject(throwing, "can't change getter if not configurable");
+        }
+      }
+    }
+
+    // Step 12.
+    current.update(desc);
+
+    // Step 13.
+    return true;
+  }
+};
+
+function IsCallable(v)
+{
+  return typeof v === "undefined" || typeof v === "function";
+}
+
+var NativeTest =
+  {
+    newObject: function newObject()
+    {
+      return {};
+    },
+    defineProperty: function defineProperty(obj, propname, propdesc)
+    {
+      Object.defineProperty(obj, propname, propdesc);
+    },
+    getDescriptor: function getDescriptor(obj, propname)
+    {
+      return Object.getOwnPropertyDescriptor(obj, propname);
+    }
+  };
+
+var ReimplTest =
+  {
+    newObject: function newObject()
+    {
+      return new CustomObject();
+    },
+    defineProperty: function defineProperty(obj, propname, propdesc)
+    {
+      assertEq(obj instanceof CustomObject, true, "obj not instanceof CustomObject");
+      if ("get" in propdesc || "set" in propdesc)
+      {
+        if ("value" in propdesc || "writable" in propdesc)
+          throw new TypeError("get/set and value/writable");
+        if (!IsCallable(propdesc.get))
+          throw new TypeError("get defined, uncallable");
+        if (!IsCallable(propdesc.set))
+          throw new TypeError("set defined, uncallable");
+      }
+      return obj.defineOwnProperty(propname, propdesc, true);
+    },
+    getDescriptor: function getDescriptor(obj, propname)
+    {
+      if (!(propname in obj.properties))
+        return undefined;
+
+      return new PropertyDescriptor(obj.properties[propname]);
+    }
+  };
+
+var JSVAL_INT_MAX = Math.pow(2, 30) - 1;
+var JSVAL_INT_MIN = -Math.pow(2, 30);
+
+
+function isValidDescriptor(propdesc)
+{
+  if ("get" in propdesc || "set" in propdesc)
+  {
+    if ("value" in propdesc || "writable" in propdesc)
+      return false;
+
+    // We permit null here simply because this test's author believes the
+    // implementation may sometime be susceptible to making mistakes in this
+    // regard and would prefer to be cautious.
+    if (propdesc.get !== null && propdesc.get !== undefined && !IsCallable(propdesc.get))
+      return false;
+    if (propdesc.set !== null && propdesc.set !== undefined && !IsCallable(propdesc.set))
+      return false;
+  }
+
+  return true;
+}
+
+
+var OMIT = {};
+var VALUES =
+  [-Infinity, JSVAL_INT_MIN, -0, +0, 1.5, JSVAL_INT_MAX, Infinity,
+   NaN, "foo", "bar", null, undefined, true, false, {}, /a/, OMIT];
+var GETS =
+  [undefined, function get1() { return 1; }, function get2() { return 2; },
+   null, 5, OMIT];
+var SETS =
+  [undefined, function set1() { return 1; }, function set2() { return 2; },
+   null, 5, OMIT];
+var ENUMERABLES = [true, false, OMIT];
+var CONFIGURABLES = [true, false, OMIT];
+var WRITABLES = [true, false, OMIT];
+
+function mapTestDescriptors(filter)
+{
+  var descs = [];
+  var desc = {};
+
+  function put(field, value)
+  {
+    if (value !== OMIT)
+      desc[field] = value;
+  }
+
+  VALUES.forEach(function(value)
+  {
+    GETS.forEach(function(get)
+    {
+      SETS.forEach(function(set)
+      {
+        ENUMERABLES.forEach(function(enumerable)
+        {
+          CONFIGURABLES.forEach(function(configurable)
+          {
+            WRITABLES.forEach(function(writable)
+            {
+              desc = {};
+              put("value", value);
+              put("get", get);
+              put("set", set);
+              put("enumerable", enumerable);
+              put("configurable", configurable);
+              put("writable", writable);
+              if (filter(desc))
+                descs.push(desc);
+            });
+          });
+        });
+      });
+    });
+  });
+
+  return descs;
+}
+
+var ALL_DESCRIPTORS = mapTestDescriptors(function(d) { return true; });
+var VALID_DESCRIPTORS = mapTestDescriptors(isValidDescriptor);
+
+function TestRunner()
+{
+  this._logLines = [];
+}
+TestRunner.prototype =
+  {
+    // MAIN METHODS
+
+    runFunctionLengthTests: function runFunctionLengthTests()
+    {
+      var self = this;
+      function functionLengthTests()
+      {
+        self._fullFunctionLengthTests(() => Function("one", "/* body */"), 1);
+        self._fullFunctionLengthTests(() => function(one, two, three=null) { }, 2);
+        self._fullFunctionLengthTests(() => (one, two, ...etc) => 0, 2);
+        self._fullFunctionLengthTests(() => ({method(){}}.method), 0);
+        self._fullFunctionLengthTests(() => Object.getOwnPropertyDescriptor({set x(v){}}, "x").set, 1);
+      }
+
+      this._runTestSet(functionLengthTests, "Function length tests completed!");
+    },
+
+    runNotPresentTests: function runNotPresentTests()
+    {
+      var self = this;
+      function notPresentTests()
+      {
+        print("Running not-present tests now...");
+
+        for (var i = 0, sz = ALL_DESCRIPTORS.length; i < sz; i++)
+          self._runSingleNotPresentTest(ALL_DESCRIPTORS[i]);
+      };
+
+      this._runTestSet(notPresentTests, "Not-present length tests completed!");
+    },
+
+    runPropertyPresentTestsFraction:
+    function runPropertyPresentTestsFraction(part, parts)
+    {
+      var self = this;
+      function propertyPresentTests()
+      {
+        print("Running already-present tests now...");
+
+        var total = VALID_DESCRIPTORS.length;
+        var start = Math.floor((part - 1) / parts * total);
+        var end = Math.floor(part / parts * total);
+
+        for (var i = start; i < end; i++)
+        {
+          var old = VALID_DESCRIPTORS[i];
+          print("Starting test with old descriptor " + old.toSource() + "...");
+
+          for (var j = 0, sz2 = VALID_DESCRIPTORS.length; j < sz2; j++)
+            self._runSinglePropertyPresentTest(old, VALID_DESCRIPTORS[j], []);
+        }
+      }
+
+      this._runTestSet(propertyPresentTests,
+                       "Property-present fraction " + part + " of " + parts +
+                       " completed!");
+    },
+
+    runNonTerminalPropertyPresentTestsFraction:
+    function runNonTerminalPropertyPresentTestsFraction(part, parts)
+    {
+      var self = this;
+
+      /*
+       * A plain old property to define on the object before redefining the
+       * originally-added property, to test redefinition of a property that's
+       * not also lastProperty.  NB: we could loop over every possible
+       * descriptor here if we wanted, even try adding more than one, but we'd
+       * hit cubic complexity and worse, and SpiderMonkey only distinguishes by
+       * the mere presence of the middle property, not its precise details.
+       */
+      var middleDefines =
+        [{
+           property: "middle",
+           descriptor:
+             { value: 17, writable: true, configurable: true, enumerable: true }
+         }];
+
+      function nonTerminalPropertyPresentTests()
+      {
+        print("Running non-terminal already-present tests now...");
+
+        var total = VALID_DESCRIPTORS.length;
+        var start = Math.floor((part - 1) / parts * total);
+        var end = Math.floor(part / parts * total);
+
+        for (var i = start; i < end; i++)
+        {
+          var old = VALID_DESCRIPTORS[i];
+          print("Starting test with old descriptor " + old.toSource() + "...");
+
+          for (var j = 0, sz2 = VALID_DESCRIPTORS.length; j < sz2; j++)
+          {
+            self._runSinglePropertyPresentTest(old, VALID_DESCRIPTORS[j],
+                                               middleDefines);
+          }
+        }
+      }
+
+      this._runTestSet(nonTerminalPropertyPresentTests,
+                       "Non-terminal property-present fraction " +
+                       part + " of " + parts + " completed!");
+    },
+
+    runDictionaryPropertyPresentTestsFraction:
+    function runDictionaryPropertyPresentTestsFraction(part, parts)
+    {
+      var self = this;
+
+      /*
+       * Add and readd properties such that the scope for the object is in
+       * dictionary mode.
+       */
+      var middleDefines =
+        [
+         {
+           property: "mid1",
+           descriptor:
+             { value: 17, writable: true, configurable: true, enumerable: true }
+         },
+         {
+           property: "mid2",
+           descriptor:
+             { value: 17, writable: true, configurable: true, enumerable: true }
+         },
+         {
+           property: "mid1",
+           descriptor:
+             { get: function g() { }, set: function s(v){}, configurable: false,
+               enumerable: true }
+         },
+         ];
+
+      function dictionaryPropertyPresentTests()
+      {
+        print("Running dictionary already-present tests now...");
+
+        var total = VALID_DESCRIPTORS.length;
+        var start = Math.floor((part - 1) / parts * total);
+        var end = Math.floor(part / parts * total);
+
+        for (var i = start; i < end; i++)
+        {
+          var old = VALID_DESCRIPTORS[i];
+          print("Starting test with old descriptor " + old.toSource() + "...");
+
+          for (var j = 0, sz2 = VALID_DESCRIPTORS.length; j < sz2; j++)
+          {
+            self._runSinglePropertyPresentTest(old, VALID_DESCRIPTORS[j],
+                                               middleDefines);
+          }
+        }
+      }
+
+      this._runTestSet(dictionaryPropertyPresentTests,
+                       "Dictionary property-present fraction " +
+                       part + " of " + parts + " completed!");
+    },
+
+
+    // HELPERS
+
+    runPropertyPresentTests: function runPropertyPresentTests()
+    {
+      print("Running already-present tests now...");
+
+      for (var i = 0, sz = VALID_DESCRIPTORS.length; i < sz; i++)
+      {
+        var old = VALID_DESCRIPTORS[i];
+        print("Starting test with old descriptor " + old.toSource() + "...");
+
+        for (var j = 0, sz2 = VALID_DESCRIPTORS.length; j < sz2; j++)
+          this._runSinglePropertyPresentTest(old, VALID_DESCRIPTORS[j], []);
+      }
+    },
+    _runTestSet: function _runTestSet(fun, completeMessage)
+    {
+      try
+      {
+        fun();
+
+        print(completeMessage);
+      }
+      catch (e)
+      {
+        print("ERROR, EXITING (line " + (e.lineNumber || -1) + "): " + e);
+        throw e;
+      }
+      finally
+      {
+        this._reportAllErrors();
+      }
+    },
+    _reportAllErrors: function _reportAllErrors()
+    {
+      var errorCount = this._logLines.length;
+      print("Full accumulated number of errors: " + errorCount);
+      if (errorCount > 0)
+        throw errorCount + " errors detected, FAIL";
+    },
+    _fullFunctionLengthTests: function _fullFunctionLengthTests(funFactory, len)
+    {
+      print("Running Function.length (" + funFactory + ") tests now...");
+
+      for (var i = 0, sz = VALID_DESCRIPTORS.length; i < sz; i++)
+      {
+        var desc = VALID_DESCRIPTORS[i];
+        this._runSingleFunctionLengthTest(funFactory(), len, desc);
+      }
+    },
+    _log: function _log(v)
+    {
+      var m = "" + v;
+      print(m);
+      this._logLines.push(m);
+    },
+    _runSingleNotPresentTest: function _runSingleNotPresentTest(desc)
+    {
+      var nativeObj = NativeTest.newObject();
+      var reimplObj = ReimplTest.newObject();
+
+      try
+      {
+        NativeTest.defineProperty(nativeObj, "foo", desc);
+      }
+      catch (e)
+      {
+        try
+        {
+          ReimplTest.defineProperty(reimplObj, "foo", desc);
+        }
+        catch (e2)
+        {
+          if (e.constructor !== e2.constructor)
+          {
+            this._log("Difference when comparing native/reimplementation " +
+                      "behavior for new descriptor " + desc.toSource() +
+                      ", native threw " + e + ", reimpl threw " + e2);
+          }
+          return;
+        }
+        this._log("Difference when comparing native/reimplementation " +
+                  "behavior for new descriptor " + desc.toSource() +
+                  ", error " + e);
+        return;
+      }
+
+      try
+      {
+        ReimplTest.defineProperty(reimplObj, "foo", desc);
+      }
+      catch (e)
+      {
+        this._log("Reimpl threw defining new descriptor " + desc.toSource() +
+                  ", error: " + e);
+        return;
+      }
+
+      var nativeDesc = NativeTest.getDescriptor(nativeObj, "foo");
+      var reimplDesc = ReimplTest.getDescriptor(reimplObj, "foo");
+      try
+      {
+        compareDescriptors(nativeDesc, reimplDesc);
+      }
+      catch (e)
+      {
+        this._log("Difference comparing returned descriptors for new " +
+                  "property defined with descriptor " + desc.toSource() +
+                  "; error: " + e);
+        return;
+      }
+    },
+    _runSinglePropertyPresentTest:
+    function _runSinglePropertyPresentTest(old, add, middleDefines)
+    {
+      var nativeObj = NativeTest.newObject();
+      var reimplObj = ReimplTest.newObject();
+
+      try
+      {
+        NativeTest.defineProperty(nativeObj, "foo", old);
+      }
+      catch (e)
+      {
+        if (!SameValue(NativeTest.getDescriptor(nativeObj, "foo"), undefined))
+        {
+          this._log("defining bad property descriptor: " + old.toSource());
+          return;
+        }
+
+        try
+        {
+          ReimplTest.defineProperty(reimplObj, "foo", old);
+        }
+        catch (e2)
+        {
+          if (!SameValue(ReimplTest.getDescriptor(reimplObj, "foo"),
+                         undefined))
+          {
+            this._log("defining bad property descriptor: " + old.toSource() +
+                      "; reimplObj: " + uneval(reimplObj));
+          }
+
+          if (e.constructor !== e2.constructor)
+          {
+            this._log("Different errors defining bad property descriptor: " +
+                      old.toSource() + "; native threw " + e + ", reimpl " +
+                      "threw " + e2);
+          }
+
+          return;
+        }
+
+        this._log("Difference defining a property with descriptor " +
+                  old.toSource() + ", error " + e);
+        return;
+      }
+
+      try
+      {
+        ReimplTest.defineProperty(reimplObj, "foo", old);
+      }
+      catch (e)
+      {
+        this._log("Difference when comparing native/reimplementation " +
+                  "behavior when adding descriptor " + add.toSource() +
+                  ", error: " + e);
+        return;
+      }
+
+      // Now add (or even readd) however many properties were specified between
+      // the original property to add and the new one, to test redefining
+      // non-last-properties and properties in scopes in dictionary mode.
+      for (var i = 0, sz = middleDefines.length; i < sz; i++)
+      {
+        var middle = middleDefines[i];
+        var prop = middle.property;
+        var desc = middle.descriptor;
+
+        try
+        {
+          NativeTest.defineProperty(nativeObj, prop, desc);
+          ReimplTest.defineProperty(reimplObj, prop, desc);
+        }
+        catch (e)
+        {
+          this._log("failure defining middle descriptor: " + desc.toSource() +
+                    ", error " + e);
+          return;
+        }
+
+        // Sanity check
+        var nativeDesc = NativeTest.getDescriptor(nativeObj, prop);
+        var reimplDesc = ReimplTest.getDescriptor(reimplObj, prop);
+
+        compareDescriptors(nativeDesc, reimplDesc);
+        compareDescriptors(nativeDesc, desc);
+      }
+
+      try
+      {
+        NativeTest.defineProperty(nativeObj, "foo", add);
+      }
+      catch (e)
+      {
+        try
+        {
+          ReimplTest.defineProperty(reimplObj, "foo", add);
+        }
+        catch (e2)
+        {
+          if (e.constructor !== e2.constructor)
+          {
+            this._log("Difference when comparing native/reimplementation " +
+                      "behavior for descriptor " + add.toSource() +
+                      " overwriting descriptor " + old.toSource() + "; " +
+                      "native threw " + e + ", reimpl threw " + e2);
+          }
+          return;
+        }
+        this._log("Difference when comparing native/reimplementation " +
+                  "behavior for added descriptor " + add.toSource() + ", " +
+                  "initial was " + old.toSource() + "; error: " + e);
+        return;
+      }
+
+      try
+      {
+        ReimplTest.defineProperty(reimplObj, "foo", add);
+      }
+      catch (e)
+      {
+        this._log("Difference when comparing native/reimplementation " +
+                  "behavior for readded descriptor " + add.toSource() + ", " +
+                  "initial was " + old.toSource() + "; native readd didn't " +
+                  "throw, reimpl add did, error: " + e);
+        return;
+      }
+
+      var nativeDesc = NativeTest.getDescriptor(nativeObj, "foo");
+      var reimplDesc = ReimplTest.getDescriptor(reimplObj, "foo");
+      try
+      {
+        compareDescriptors(nativeDesc, reimplDesc);
+      }
+      catch (e)
+      {
+        this._log("Difference comparing returned descriptors for readded " +
+                  "property defined with descriptor " + add.toSource() + "; " +
+                  "initial was " + old.toSource() + "; error: " + e);
+        return;
+      }
+    },
+    _runSingleFunctionLengthTest: function _runSingleFunctionLengthTest(fun, len, desc)
+    {
+      var nativeObj = fun;
+      var reimplObj = ReimplTest.newObject();
+      ReimplTest.defineProperty(reimplObj, "length",
+      {
+        value: len,
+        enumerable: false,
+        configurable: true,
+        writable: false
+      });
+
+      try
+      {
+        NativeTest.defineProperty(nativeObj, "length", desc);
+      }
+      catch (e)
+      {
+        try
+        {
+          ReimplTest.defineProperty(reimplObj, "length", desc);
+        }
+        catch (e2)
+        {
+          if (e.constructor !== e2.constructor)
+          {
+            this._log("Difference when comparing native/reimplementation " +
+                      "behavior defining fun.length with " + desc.toSource() +
+                      "; native threw " + e + ", reimpl threw " + e2);
+          }
+          return;
+        }
+        this._log("Difference when comparing Function.length native/reimpl " +
+                  "behavior for descriptor " + desc.toSource() +
+                  ", native impl threw error " + e);
+        return;
+      }
+
+      try
+      {
+        ReimplTest.defineProperty(reimplObj, "length", desc);
+      }
+      catch (e)
+      {
+        this._log("Difference defining new Function.length descriptor: impl " +
+                  "succeeded, reimpl threw for descriptor " +
+                  desc.toSource() + ", error: " + e);
+        return;
+      }
+
+      var nativeDesc = NativeTest.getDescriptor(nativeObj, "length");
+      var reimplDesc = ReimplTest.getDescriptor(reimplObj, "length");
+      try
+      {
+        compareDescriptors(nativeDesc, reimplDesc);
+      }
+      catch (e)
+      {
+        this._log("Difference comparing returned descriptors for " +
+                  "Function.length with descriptor " + desc.toSource() +
+                  "; error: " + e);
+        return;
+      }
+    }
+  };
+
+function runDictionaryPropertyPresentTestsFraction(PART, PARTS)
+{
+  var testfile =
+    '15.2.3.6-dictionary-redefinition-' + PART + '-of-' + PARTS + '.js';
+  var BUGNUMBER = 560566;
+  var summary =
+    'ES5 Object.defineProperty(O, P, Attributes): dictionary redefinition ' +
+    PART + ' of ' + PARTS;
+
+  print(BUGNUMBER + ": " + summary);
+
+  try
+  {
+    new TestRunner().runDictionaryPropertyPresentTestsFraction(PART, PARTS);
+  }
+  catch (e)
+  {
+    throw "Error thrown during testing: " + e +
+            " at line " + e.lineNumber + "\n" +
+          (e.stack
+            ? "Stack: " + e.stack.split("\n").slice(2).join("\n") + "\n"
+            : "");
+  }
+
+  if (typeof reportCompare === "function")
+    reportCompare(true, true);
+
+  print("Tests complete!");
+}
+
+function runNonTerminalPropertyPresentTestsFraction(PART, PARTS)
+{
+  var BUGNUMBER = 560566;
+  var summary =
+    'ES5 Object.defineProperty(O, P, Attributes): middle redefinition ' +
+    PART + ' of ' + PARTS;
+
+  print(BUGNUMBER + ": " + summary);
+
+
+  /**************
+   * BEGIN TEST *
+   **************/
+
+  try
+  {
+    new TestRunner().runNonTerminalPropertyPresentTestsFraction(PART, PARTS);
+  }
+  catch (e)
+  {
+    throw "Error thrown during testing: " + e +
+            " at line " + e.lineNumber + "\n" +
+          (e.stack
+            ? "Stack: " + e.stack.split("\n").slice(2).join("\n") + "\n"
+            : "");
+  }
+
+  /******************************************************************************/
+
+  if (typeof reportCompare === "function")
+    reportCompare(true, true);
+
+  print("Tests complete!");
+}