Introduce Array.splice builtin.

test/mjsunit/array-splice.js

Index: test/mjsunit/array-splice.js
diff --git a/test/mjsunit/array-splice.js b/test/mjsunit/array-splice.js
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+// Copyright 2010 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.
+
+// Check that splicing array of holes keeps it as array of holes
+(function() {
+  for (var i = 0; i < 7; i++) {
+    var array = new Array(10);
+    var spliced = array.splice(1, 1, 'one', 'two');
+    assertEquals(1, spliced.length);
+    assertFalse(0 in spliced);
+
+    assertEquals(11, array.length);
+    assertFalse(0 in array);
+    assertTrue(1 in array);
+    assertTrue(2 in array);
+    assertFalse(3 in array);
+  }
+})();
+
+
+// Check various forms of arguments omission.
+(function() {
+  var array;
+  for (var i = 0; i < 7; i++) {
+    // SpiderMonkey and JSC return undefined in the case where no
+    // arguments are given instead of using the implicit undefined
+    // arguments.  This does not follow ECMA-262, but we do the same for
+    // compatibility.
+    // TraceMonkey follows ECMA-262 though.
+    array = [1, 2, 3]
+    assertEquals(undefined, array.splice());
+    assertEquals([1, 2, 3], array);
+
+    // SpiderMonkey, TraceMonkey and JSC treat the case where no delete count is
+    // given differently from when an undefined delete count is given.
+    // This does not follow ECMA-262, but we do the same for
+    // compatibility.
+    array = [1, 2, 3]
+    assertEquals([1, 2, 3], array.splice(0));
+    assertEquals([], array);
+
+    array = [1, 2, 3]
+    assertEquals([1, 2, 3], array.splice(undefined));
+    assertEquals([], array);
+
+    array = [1, 2, 3]
+    assertEquals([1, 2, 3], array.splice("foobar"));
+    assertEquals([], array);
+
+    array = [1, 2, 3]
+    assertEquals([], array.splice(undefined, undefined));
+    assertEquals([1, 2, 3], array);
+
+    array = [1, 2, 3]
+    assertEquals([], array.splice("foobar", undefined));
+    assertEquals([1, 2, 3], array);
+
+    array = [1, 2, 3]
+    assertEquals([], array.splice(undefined, "foobar"));
+    assertEquals([1, 2, 3], array);
+
+    array = [1, 2, 3]
+    assertEquals([], array.splice("foobar", "foobar"));
+    assertEquals([1, 2, 3], array);
+  }
+})();
+
+
+// Check variants of negatives and positive indices.
+(function() {
+  var array, spliced;
+  for (var i = 0; i < 7; i++) {
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(-100);
+    assertEquals([], array);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(-3);
+    assertEquals([1, 2, 3, 4], array);
+    assertEquals([5, 6, 7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(4);
+    assertEquals([1, 2, 3, 4], array);
+    assertEquals([5, 6, 7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(6);
+    assertEquals([1, 2, 3, 4, 5, 6], array);
+    assertEquals([7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(7);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], array);
+    assertEquals([], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(8);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], array);
+    assertEquals([], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(100);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], array);
+    assertEquals([], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, -100);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], array);
+    assertEquals([], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, -3);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], array);
+    assertEquals([], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, 4);
+    assertEquals([5, 6, 7], array);
+    assertEquals([1, 2, 3, 4], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, 6);
+    assertEquals([7], array);
+    assertEquals([1, 2, 3, 4, 5, 6], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, 7);
+    assertEquals([], array);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, 8);
+    assertEquals([], array);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], spliced);
+
+    array = [1, 2, 3, 4, 5, 6, 7];
+    spliced = array.splice(0, 100);
+    assertEquals([], array);
+    assertEquals([1, 2, 3, 4, 5, 6, 7], spliced);
+
+    // Some exotic cases.
+    obj = { toString: function() { throw 'Exception'; } };
+
+    // Throwing an exception in conversion:
+    try {
+      [1, 2, 3].splice(obj, 3);
+      throw 'Should have thrown';
+    } catch (e) {
+      assertEquals('Exception', e);
+    }
+
+    try {
+      [1, 2, 3].splice(0, obj, 3);
+      throw 'Should have thrown';
+    } catch (e) {
+      assertEquals('Exception', e);
+    }
+
+    array = [1, 2, 3];
+    array.splice(0, 3, obj);
+    assertEquals(1, array.length);
+
+    // Custom conversion:
+    array = [1, 2, 3];
+    spliced = array.splice({valueOf: function() { return 1; }},
+                           {toString: function() { return 2; }},
+                           'one', 'two');
+    assertEquals([2, 3], spliced);
+    assertEquals([1, 'one', 'two'], array);
+  }
+})();
+
+
+// Nasty: modify the array in ToInteger.
+(function() {
+  var array = [];
+  var spliced;
+
+  for (var i = 0; i < 13; i++) {
+    bad_start = { valueOf: function() { array.push(2*i); return -1; } };
+    bad_count = { valueOf: function() { array.push(2*i + 1); return 1; } };
+    spliced = array.splice(bad_start, bad_count);
+    // According to the spec (15.4.4.12), length is calculated before
+    // performing ToInteger on arguments.  However, v8 ignores elements
+    // we add while converting, so we need corrective pushes.
+    array.push(2*i); array.push(2*i + 1);
+    if (i == 0) {
+      assertEquals([], spliced);  // Length was 0, nothing to get.
+      assertEquals([0, 1], array);
+    } else {
+      // When we start splice, array is [0 .. 2*i - 1], so we get
+      // as a result [2*i], this element is removed from the array,
+      // but [2 * i, 2 * i + 1] are added.
+      assertEquals([2 * i - 1], spliced);
+      assertEquals(2 * i, array[i]);
+      assertEquals(2 * i + 1, array[i + 1]);
+    }
+  }
+})();
+
+
+// Now check the case with array of holes and some elements on prototype.
+(function() {
+  var len = 9;
+
+  var at3 = "@3";
+  var at7 = "@7";
+
+  for (var i = 0; i < 7; i++) {
+    var array = new Array(len);
+    Array.prototype[3] = at3;
+    Array.prototype[7] = at7;
+
+    var spliced = array.splice(2, 2, 'one', undefined, 'two');
+
+    // Second hole (at index 3) of array turns into
+    // value of Array.prototype[3] while copying.
+    assertEquals([, at3], spliced);
+    assertEquals([, , 'one', undefined, 'two', , , at7, at7, ,], array);
+
+    // ... but array[7] is actually a hole:
+    assertTrue(delete Array.prototype[7]);
+    assertEquals(undefined, array[7]);
+
+    // and now check hasOwnProperty
+    assertFalse(array.hasOwnProperty(0));
+    assertFalse(array.hasOwnProperty(1));
+    assertTrue(array.hasOwnProperty(2));
+    assertTrue(array.hasOwnProperty(3));
+    assertTrue(array.hasOwnProperty(4));
+    assertFalse(array.hasOwnProperty(5));
+    assertFalse(array.hasOwnProperty(6));
+    assertFalse(array.hasOwnProperty(7));
+    assertTrue(array.hasOwnProperty(8));
+    assertFalse(array.hasOwnProperty(9));
+
+    // and now check couple of indices above length.
+    assertFalse(array.hasOwnProperty(10));
+    assertFalse(array.hasOwnProperty(15));
+    assertFalse(array.hasOwnProperty(31));
+    assertFalse(array.hasOwnProperty(63));
+    assertFalse(array.hasOwnProperty(2 << 32 - 1));
+  }
+})();