Fix issue 1361 - Implement ES5 Array.prototype.toString.

BUG=v8:1361
TEST=mjsunit/array-tostring

Review URL: http://codereview.chromium.org/8124025

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9519 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/array.js

@@ -201,17 +201,14 @@ function ConvertToString(x) {
 
 
 function ConvertToLocaleString(e) {
-  if (e == null) {
+  if (IS_NULL_OR_UNDEFINED(e)) {
     return '';
   } else {
-    // e_obj's toLocaleString might be overwritten, check if it is a function.
-    // Call ToString if toLocaleString is not a function.
-    // See issue 877615.
+    // According to ES5, seciton 15.4.4.3, the toLocaleString conversion
+    // must throw a TypeError if ToObject(e).toLocaleString isn't
+    // callable.
     var e_obj = ToObject(e);
-    if (IS_SPEC_FUNCTION(e_obj.toLocaleString))
-      return ToString(e_obj.toLocaleString());
-    else
-      return ToString(e);
+    return %ToString(e_obj.toLocaleString());
   }
 }
 
@@ -381,18 +378,31 @@ function SimpleMove(array, start_i, del_count, len, num_additional_args) {
 
 
 function ArrayToString() {
-  if (!IS_ARRAY(this)) {
-    throw new $TypeError('Array.prototype.toString is not generic');
+  var array;
+  var func;
+  if (IS_ARRAY(this)) {
+    func = this.join;
+    if (func === ArrayJoin) {
+      return Join(this, this.length, ',', ConvertToString);
+    }
+    array = this;
+  } else {
+    array = ToObject(this);
+    func = array.join;
   }
-  return Join(this, this.length, ',', ConvertToString);
+  if (!IS_SPEC_FUNCTION(func)) {
+    return %_CallFunction(array, ObjectToString);
+  }
+  return %_CallFunction(array, func);
 }
 
 
 function ArrayToLocaleString() {
-  if (!IS_ARRAY(this)) {
-    throw new $TypeError('Array.prototype.toString is not generic');
-  }
-  return Join(this, this.length, ',', ConvertToLocaleString);
+  var array = ToObject(this);
+  var arrayLen = array.length;
+  var len = TO_UINT32(arrayLen);
+  if (len === 0) return "";
+  return Join(array, len, ',', ConvertToLocaleString);
 }
 
 

test/mjsunit/array-tostring.js

+// Copyright 2011 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Array's toString should call the object's own join method, if one exists and
+// is callable. Otherwise, just use the original Object.toString function.
+
+var success = "[test success]";
+var expectedThis;
+function testJoin() {
+  assertEquals(0, arguments.length);
+  assertSame(expectedThis, this);
+  return success;
+}
+
+
+// On an Array object.
+
+// Default case.
+var a1 = [1, 2, 3];
+assertEquals(a1.join(), a1.toString());
+
+// Non-standard "join" function is called correctly.
+var a2 = [1, 2, 3];
+a2.join = testJoin;
+expectedThis = a2;
+assertEquals(success, a2.toString());
+
+// Non-callable join function is ignored and Object.prototype.toString is
+// used instead.
+var a3 = [1, 2, 3];
+a3.join = "not callable";
+assertEquals("[object Array]", a3.toString());
+
+// Non-existing join function is treated same as non-callable.
+var a4 = [1, 2, 3];
+a4.__proto__ = { toString: Array.prototype.toString };
+// No join on Array.
+assertEquals("[object Array]", a4.toString());
+
+
+// On a non-Array object.
+
+// Default looks-like-an-array case.
+var o1 = {length: 3, 0: 1, 1: 2, 2: 3,
+          toString: Array.prototype.toString,
+          join: Array.prototype.join};
+assertEquals(o1.join(), o1.toString());
+
+
+// Non-standard join is called correctly.
+// Check that we don't read, e.g., length before calling join.
+var o2 = {toString : Array.prototype.toString,
+          join: testJoin,
+          get length() { assertUnreachable(); },
+          get 0() { assertUnreachable(); }};
+expectedThis = o2;
+assertEquals(success, o2.toString());
+
+// Non-standard join is called even if it looks like an array.
+var o3 = {length: 3, 0: 1, 1: 2, 2: 3,
+          toString: Array.prototype.toString,
+          join: testJoin};
+expectedThis = o3;
+assertEquals(success, o3.toString());
+
+// Non-callable join works same as for Array.
+var o4 = {length: 3, 0: 1, 1: 2, 2: 3,
+          toString: Array.prototype.toString,
+          join: "not callable"};
+assertEquals("[object Object]", o4.toString());
+
+
+// Non-existing join works same as for Array.
+var o5 = {length: 3, 0: 1, 1: 2, 2: 3,
+          toString: Array.prototype.toString
+          /* no join */};
+assertEquals("[object Object]", o5.toString());
+
+
+// Test that ToObject is called before getting "join", so the instance
+// that "join" is read from is the same one passed as receiver later.
+var called_before = false;
+expectedThis = null;
+Object.defineProperty(Number.prototype, "join", {get: function() {
+            assertFalse(called_before);
+            called_before = true;
+            expectedThis = this;
+            return testJoin;
+        }});
+Number.prototype.arrayToString = Array.prototype.toString;
+assertEquals(success, (42).arrayToString());
+
+// ----------------------------------------------------------
+// Testing Array.prototype.toLocaleString
+
+// Ensure that it never uses Array.prototype.toString for anything.
+Array.prototype.toString = function() { assertUnreachable(); };
+
+// Default case.
+var la1 = [1, [2, 3], 4];
+assertEquals("1,2,3,4", la1.toLocaleString());
+
+// Used on a string (which looks like an array of characters).
+String.prototype.toLocaleString = Array.prototype.toLocaleString;
+assertEquals("1,2,3,4", "1234".toLocaleString());
+
+// If toLocaleString of element is not callable, throw a TypeError.
+var la2 = [1, {toLocaleString: "not callable"}, 3];
+assertThrows(function() { la2.toLocaleString(); }, TypeError);
+
+// If toLocaleString of element is callable, call it.
+var la3 = [1, {toLocaleString: function() { return "XX";}}, 3];
+assertEquals("1,XX,3", la3.toLocaleString());
+
+// Omitted elements, as well as undefined and null, become empty string.
+var la4 = [1, null, 3, undefined, 5,, 7];
+assertEquals("1,,3,,5,,7", la4.toLocaleString());
+
+
+// ToObject is called first and the same object is being used for the
+// rest of the operations.
+Object.defineProperty(Number.prototype, "length", {
+    get: function() {
+      exptectedThis = this;
+      return 3;
+    }});
+for (var i = 0; i < 3; i++) {
+  Object.defineProperty(Number.prototype, i, {
+      get: function() {
+        assertEquals(expectedThis, this);
+        return +this;
+      }});
+}
+Number.prototype.arrayToLocaleString = Array.prototype.toLocaleString;
+assertEquals("42,42,42", (42).arrayToLocaleString());
\ No newline at end of file

test/mjsunit/regress/regress-877615.js

@@ -25,13 +25,13 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-Number.prototype.toLocaleString = function() { return 'invalid'};
-assertEquals([1].toLocaleString(), 'invalid');  // invalid
+Number.prototype.toLocaleString = function() { return 'invalid'; };
+assertEquals('invalid', [1].toLocaleString());  // invalid
 
 Number.prototype.toLocaleString = 'invalid';
-assertEquals([1].toLocaleString(), '1');  // 1
+assertThrows(function() { [1].toLocaleString(); });  // Not callable.
 
+delete Number.prototype.toLocaleString;
 Number.prototype.toString = function() { return 'invalid' };
-assertEquals([1].toLocaleString(), '1');  // 1
-assertEquals([1].toString(), '1');        // 1
-
+assertEquals([1].toLocaleString(), 'invalid');  // Uses ToObject on elements.
+assertEquals([1].toString(), '1');        // Uses ToString directly on elements.