Add Array.prototype.includes

test/mjsunit/harmony/array-includes.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --harmony-array-includes
+
+// Largely ported from
+// https://github.com/tc39/Array.prototype.includes/tree/master/test
+// using https://www.npmjs.org/package/test262-to-mjsunit with further edits
+
+
+// Array.prototype.includes sees a new element added by a getter that is hit
+// during iteration
+(function() {
+  var arrayLike = {
+    length: 5,
+    0: "a",
+
+    get 1() {
+      this[2] = "c";
+      return "b";
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike, "c"));
+})();
+
+
+// Array.prototype.includes works on array-like objects
+(function() {
+  var arrayLike1 = {
+    length: 5,
+    0: "a",
+    1: "b"
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike1, "a"));
+  assertFalse(Array.prototype.includes.call(arrayLike1, "c"));
+
+  var arrayLike2 = {
+    length: 2,
+    0: "a",
+    1: "b",
+    2: "c"
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike2, "b"));
+  assertFalse(Array.prototype.includes.call(arrayLike2, "c"));
+})();
+
+
+// Array.prototype.includes should fail if used on a null or undefined this
+(function() {
+  assertThrows(function() {
+    Array.prototype.includes.call(null, "a");
+  }, TypeError);
+
+  assertThrows(function() {
+    Array.prototype.includes.call(undefined, "a");
+  }, TypeError);
+})();
+
+
+// Array.prototype.includes should terminate if getting an index throws an
+// exception
+(function() {
+  function Test262Error() {}
+
+  var trappedZero = {
+    length: 2,
+
+    get 0() {
+      throw new Test262Error();
+    },
+
+    get 1() {
+      assertUnreachable("Should not try to get the first element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(trappedZero, "a");
+  }, Test262Error);
+})();
+
+
+// Array.prototype.includes should terminate if ToNumber ends up being called on
+// a symbol fromIndex
+(function() {
+  var trappedZero = {
+    length: 1,
+
+    get 0() {
+      assertUnreachable("Should not try to get the zeroth element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(trappedZero, "a", Symbol());
+  }, TypeError);
+})();
+
+
+// Array.prototype.includes should terminate if an exception occurs converting
+// the fromIndex to a number
+(function() {
+  function Test262Error() {}
+
+  var fromIndex = {
+    valueOf: function() {
+      throw new Test262Error();
+    }
+  };
+
+  var trappedZero = {
+    length: 1,
+
+    get 0() {
+      assertUnreachable("Should not try to get the zeroth element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(trappedZero, "a", fromIndex);
+  }, Test262Error);
+})();
+
+
+// Array.prototype.includes should terminate if an exception occurs getting the
+// length
+(function() {
+  function Test262Error() {}
+
+  var fromIndexTrap = {
+    valueOf: function() {
+      assertUnreachable("Should not try to call ToInteger on valueOf");
+    }
+  };
+
+  var throwingLength = {
+    get length() {
+      throw new Test262Error();
+    },
+
+    get 0() {
+      assertUnreachable("Should not try to get the zeroth element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(throwingLength, "a", fromIndexTrap);
+  }, Test262Error);
+})();
+
+
+// Array.prototype.includes should terminate if ToLength ends up being called on
+// a symbol length
+(function() {
+  var fromIndexTrap = {
+    valueOf: function() {
+      assertUnreachable("Should not try to call ToInteger on valueOf");
+    }
+  };
+
+  var badLength = {
+    length: Symbol(),
+
+    get 0() {
+      assertUnreachable("Should not try to get the zeroth element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(badLength, "a", fromIndexTrap);
+  }, TypeError);
+})();
+
+
+// Array.prototype.includes should terminate if an exception occurs converting
+// the length to a number
+(function() {
+  function Test262Error() {}
+
+  var fromIndexTrap = {
+    valueOf: function() {
+      assertUnreachable("Should not try to call ToInteger on valueOf");
+    }
+  };
+
+  var badLength = {
+    length: {
+      valueOf: function() {
+        throw new Test262Error();
+      }
+    },
+
+    get 0() {
+      assertUnreachable("Should not try to get the zeroth element");
+    }
+  };
+
+  assertThrows(function() {
+    Array.prototype.includes.call(badLength, "a", fromIndexTrap);
+  }, Test262Error);
+})();
+
+
+// Array.prototype.includes should search the whole array, as the optional
+// second argument fromIndex defaults to 0
+(function() {
+  assertTrue([10, 11].includes(10));
+  assertTrue([10, 11].includes(11));
+
+  var arrayLike = {
+    length: 2,
+
+    get 0() {
+      return "1";
+    },
+
+    get 1() {
+      return "2";
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike, "1"));
+  assertTrue(Array.prototype.includes.call(arrayLike, "2"));
+})();
+
+
+// Array.prototype.includes returns false if fromIndex is greater or equal to
+// the length of the array
+(function() {
+  assertFalse([1, 2].includes(2, 3));
+  assertFalse([1, 2].includes(2, 2));
+
+  var arrayLikeWithTrap = {
+    length: 2,
+
+    get 0() {
+      assertUnreachable("Getter for 0 was called");
+    },
+
+    get 1() {
+      assertUnreachable("Getter for 1 was called");
+    }
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTrap, "c", 2));
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTrap, "c", 3));
+})();
+
+
+// Array.prototype.includes searches the whole array if the computed index from
+// the given negative fromIndex argument is less than 0
+(function() {
+  assertTrue([1, 3].includes(1, -4));
+  assertTrue([1, 3].includes(3, -4));
+
+  var arrayLike = {
+    length: 2,
+    0: "a",
+
+    get 1() {
+      return "b";
+    },
+
+    get "-1"() {
+      assertUnreachable("Should not try to get the element at index -1");
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike, "a", -4));
+  assertTrue(Array.prototype.includes.call(arrayLike, "b", -4));
+})();
+
+
+// Array.prototype.includes should use a negative value as the offset from the
+// end of the array to compute fromIndex
+(function() {
+  assertTrue([12, 13].includes(13, -1));
+  assertFalse([12, 13].includes(12, -1));
+  assertTrue([12, 13].includes(12, -2));
+
+  var arrayLike = {
+    length: 2,
+
+    get 0() {
+      return "a";
+    },
+
+    get 1() {
+      return "b";
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLike, "b", -1));
+  assertFalse(Array.prototype.includes.call(arrayLike, "a", -1));
+  assertTrue(Array.prototype.includes.call(arrayLike, "a", -2));
+})();
+
+
+// Array.prototype.includes converts its fromIndex parameter to an integer
+(function() {
+  assertFalse(["a", "b"].includes("a", 2.3));
+
+  var arrayLikeWithTraps = {
+    length: 2,
+
+    get 0() {
+      assertUnreachable("Getter for 0 was called");
+    },
+
+    get 1() {
+      assertUnreachable("Getter for 1 was called");
+    }
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTraps, "c", 2.1));
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTraps, "c", +Infinity));
+  assertTrue(["a", "b", "c"].includes("a", -Infinity));
+  assertTrue(["a", "b", "c"].includes("c", 2.9));
+  assertTrue(["a", "b", "c"].includes("c", NaN));
+
+  var arrayLikeWithTrapAfterZero = {
+    length: 2,
+
+    get 0() {
+      return "a";
+    },
+
+    get 1() {
+      assertUnreachable("Getter for 1 was called");
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(arrayLikeWithTrapAfterZero, "a", NaN));
+
+  var numberLike = {
+    valueOf: function() {
+      return 2;
+    }
+  };
+
+  assertFalse(["a", "b", "c"].includes("a", numberLike));
+  assertFalse(["a", "b", "c"].includes("a", "2"));
+  assertTrue(["a", "b", "c"].includes("c", numberLike));
+  assertTrue(["a", "b", "c"].includes("c", "2"));
+})();
+
+
+// Array.prototype.includes should have length 1
+(function() {
+  assertEquals(1, Array.prototype.includes.length);
+})();
+
+
+// Array.prototype.includes should have name property with value 'includes'
+(function() {
+  assertEquals("includes", Array.prototype.includes.name);
+})();
+
+
+// !!! Test failed to convert:
+// Cannot convert tests with includes.
+// !!!
+
+
+// Array.prototype.includes does not skip holes; if the array has a prototype it
+// gets from that
+(function() {
+  var holesEverywhere = [,,,];
+
+  holesEverywhere.__proto__ = {
+    1: "a"
+  };
+
+  holesEverywhere.__proto__.__proto__ = Array.prototype;
+  assertTrue(holesEverywhere.includes("a"));
+  var oneHole = ["a", "b",, "d"];
+
+  oneHole.__proto__ = {
+    get 2() {
+      return "c";
+    }
+  };
+
+  assertTrue(Array.prototype.includes.call(oneHole, "c"));
+})();
+
+
+// Array.prototype.includes does not skip holes; instead it treates them as
+// undefined
+(function() {
+  assertTrue([,,,].includes(undefined));
+  assertTrue(["a", "b",, "d"].includes(undefined));
+})();
+
+
+// Array.prototype.includes gets length property from the prototype if it's
+// available
+(function() {
+  var proto = {
+    length: 1
+  };
+
+  var arrayLike = Object.create(proto);
+  arrayLike[0] = "a";
+
+  Object.defineProperty(arrayLike, "1", {
+    get: function() {
+      assertUnreachable("Getter for 1 was called");
+    }
+  });
+
+  assertTrue(Array.prototype.includes.call(arrayLike, "a"));
+})();
+
+
+// Array.prototype.includes treats a missing length property as zero
+(function() {
+  var arrayLikeWithTraps = {
+    get 0() {
+      assertUnreachable("Getter for 0 was called");
+    },
+
+    get 1() {
+      assertUnreachable("Getter for 1 was called");
+    }
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTraps, "a"));
+})();
+
+
+// Array.prototype.includes should always return false on negative-length
+// objects
+(function() {
+  assertFalse(Array.prototype.includes.call({
+    length: -1
+  }, 2));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -2
+  }));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -Infinity
+  }, undefined));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -Math.pow(2, 53)
+  }, NaN));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -1,
+    "-1": 2
+  }, 2));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -3,
+    "-1": 2
+  }, 2));
+
+  assertFalse(Array.prototype.includes.call({
+    length: -Infinity,
+    "-1": 2
+  }, 2));
+
+  var arrayLikeWithTrap = {
+    length: -1,
+
+    get 0() {
+      assertUnreachable("Getter for 0 was called");
+    }
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLikeWithTrap, 2));
+})();
+
+
+// Array.prototype.includes should clamp positive lengths to 2^53 - 1
+(function() {
+  var fromIndexForLargeIndexTests = 9007199254740990;
+
+  assertFalse(Array.prototype.includes.call({
+    length: 1
+  }, 2));
+
+  assertTrue(Array.prototype.includes.call({
+    length: 1,
+    0: "a"
+  }, "a"));
+
+  assertTrue(Array.prototype.includes.call({
+    length: +Infinity,
+    0: "a"
+  }, "a"));
+
+  assertFalse(Array.prototype.includes.call({
+    length: +Infinity
+  }, "a", fromIndexForLargeIndexTests));
+
+  var arrayLikeWithTrap = {
+    length: +Infinity,
+
+    get 9007199254740992() {
+      assertUnreachable("Getter for 9007199254740992 (i.e. 2^53) was called");
+    },
+
+    "9007199254740993": "a"
+  };
+
+  assertFalse(
+    Array.prototype.includes.call(arrayLikeWithTrap, "a", fromIndexForLargeIndexTests)
+  );
+
+  var arrayLikeWithTooBigLength = {
+    length: 9007199254740996,
+    "9007199254740992": "a"
+  };
+
+  assertFalse(
+    Array.prototype.includes.call(arrayLikeWithTooBigLength, "a", fromIndexForLargeIndexTests)
+  );
+})();
+
+
+// Array.prototype.includes should always return false on zero-length objects
+(function() {
+  assertFalse([].includes(2));
+  assertFalse([].includes());
+  assertFalse([].includes(undefined));
+  assertFalse([].includes(NaN));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0
+  }, 2));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0
+  }));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0
+  }, undefined));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0
+  }, NaN));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0,
+    0: 2
+  }, 2));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0,
+    0: undefined
+  }));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0,
+    0: undefined
+  }, undefined));
+
+  assertFalse(Array.prototype.includes.call({
+    length: 0,
+    0: NaN
+  }, NaN));
+
+  var arrayLikeWithTrap = {
+    length: 0,
+
+    get 0() {
+      assertUnreachable("Getter for 0 was called");
+    }
+  };
+
+  Array.prototype.includes.call(arrayLikeWithTrap);
+
+  var trappedFromIndex = {
+    valueOf: function() {
+      assertUnreachable("Should not try to convert fromIndex to a number on a zero-length array");
+    }
+  };
+
+  [].includes("a", trappedFromIndex);
+
+  Array.prototype.includes.call({
+    length: 0
+  }, trappedFromIndex);
+})();
+
+
+// Array.prototype.includes works on objects
+(function() {
+  assertFalse(["a", "b", "c"].includes({}));
+  assertFalse([{}, {}].includes({}));
+  var obj = {};
+  assertTrue([obj].includes(obj));
+  assertFalse([obj].includes(obj, 1));
+  assertTrue([obj, obj].includes(obj, 1));
+
+  var stringyObject = {
+    toString: function() {
+      return "a";
+    }
+  };
+
+  assertFalse(["a", "b", obj].includes(stringyObject));
+})();
+
+
+// Array.prototype.includes does not see an element removed by a getter that is
+// hit during iteration
+(function() {
+  var arrayLike = {
+    length: 5,
+    0: "a",
+
+    get 1() {
+      delete this[2];
+      return "b";
+    },
+
+    2: "c"
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLike, "c"));
+})();
+
+
+// Array.prototype.includes should use the SameValueZero algorithm to compare
+(function() {
+  assertTrue([1, 2, 3].includes(2));
+  assertFalse([1, 2, 3].includes(4));
+  assertTrue([1, 2, NaN].includes(NaN));
+  assertTrue([1, 2, -0].includes(+0));
+  assertTrue([1, 2, -0].includes(-0));
+  assertTrue([1, 2, +0].includes(-0));
+  assertTrue([1, 2, +0].includes(+0));
+  assertFalse([1, 2, -Infinity].includes(+Infinity));
+  assertTrue([1, 2, -Infinity].includes(-Infinity));
+  assertFalse([1, 2, +Infinity].includes(-Infinity));
+  assertTrue([1, 2, +Infinity].includes(+Infinity));
+})();
+
+
+// Array.prototype.includes stops once it hits the length of an array-like, even
+// if there are more after
+(function() {
+  var arrayLike = {
+    length: 2,
+    0: "a",
+    1: "b",
+
+    get 2() {
+      assertUnreachable("Should not try to get the second element");
+    }
+  };
+
+  assertFalse(Array.prototype.includes.call(arrayLike, "c"));
+})();
+
+
+// Array.prototype.includes works on typed arrays
+(function() {
+  assertTrue(Array.prototype.includes.call(new Uint8Array([1, 2, 3]), 2));
+
+  assertTrue(
+    Array.prototype.includes.call(new Float32Array([2.5, 3.14, Math.PI]), 3.1415927410125732)
+  );
+
+  assertFalse(Array.prototype.includes.call(new Uint8Array([1, 2, 3]), 4));
+  assertFalse(Array.prototype.includes.call(new Uint8Array([1, 2, 3]), 2, 2));
+})();