jasmine/spec/core/matchers/matchersUtilSpec.js

describe("matchersUtil", function() {
  describe("equals", function() {
    it("passes for literals that are triple-equal", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(null, null)).toBe(true);
      expect(matchersUtil.equals(void 0, void 0)).toBe(true);
    });

    it("fails for things that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({a: "foo"}, 1)).toBe(false);
    });

    it("passes for Strings that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals("foo", "foo")).toBe(true);
    });

    it("fails for Strings that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals("foo", "bar")).toBe(false);
    });

    it("passes for Numbers that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(123, 123)).toBe(true);
    });

    it("fails for Numbers that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(123, 456)).toBe(false);
    });

    it("passes for Dates that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Date("Jan 1, 1970"), new Date("Jan 1, 1970"))).toBe(true);
    });

    it("fails for Dates that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Date("Jan 1, 1970"), new Date("Feb 3, 1991"))).toBe(false);
    });

    it("passes for Booleans that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(true, true)).toBe(true);
    });

    it("fails for Booleans that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(true, false)).toBe(false);
    });

    it("passes for RegExps that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(/foo/, /foo/)).toBe(true);
    });

    it("fails for RegExps that are not equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(/foo/, /bar/)).toBe(false);
      expect(matchersUtil.equals(new RegExp("foo", "i"), new RegExp("foo"))).toBe(false);
    });

    it("passes for Arrays that are equivalent", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals([1, 2], [1, 2])).toBe(true);
    });

    it("passes for Arrays that are equivalent, with elements added by changing length", function() {
      var foo = [],
        matchersUtil = new jasmineUnderTest.MatchersUtil();
      foo.length = 1;

      expect(matchersUtil.equals(foo, [undefined])).toBe(true);
    });

    it("fails for Arrays that have different lengths", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals([1, 2], [1, 2, 3])).toBe(false);
    });

    it("fails for Arrays that have different elements", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals([1, 2, 3], [1, 5, 3])).toBe(false);
    });

    it("fails for Arrays whose contents are equivalent, but have differing properties", function() {
      var one = [1,2,3],
        two = [1,2,3],
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      one.foo = 'bar';
      two.foo = 'baz';

      expect(matchersUtil.equals(one, two)).toBe(false);
    });

    it("passes for Arrays with equivalent contents and properties", function() {
      var one = [1,2,3],
        two = [1,2,3],
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      one.foo = 'bar';
      two.foo = 'bar';

      expect(matchersUtil.equals(one, two)).toBe(true);
    });

    it("passes for Errors that are the same type and have the same message", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Error("foo"), new Error("foo"))).toBe(true);
    });

    it("fails for Errors that are the same type and have different messages", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Error("foo"), new Error("bar"))).toBe(false);
    });

    it("fails for objects with different constructors", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      function One() {}
      function Two() {}

      expect(matchersUtil.equals(new One(), new Two())).toBe(false);
    });

    it("passes for Objects that are equivalent (simple case)", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({a: "foo"}, {a: "foo"})).toBe(true);
    });

    it("fails for Objects that are not equivalent (simple case)", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({a: "foo"}, {a: "bar"})).toBe(false);
    });

    it("passes for Objects that are equivalent (deep case)", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({a: "foo", b: { c: "bar"}}, {a: "foo", b: { c: "bar"}})).toBe(true);
    });

    it("fails for Objects that are not equivalent (deep case)", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({a: "foo", b: { c: "baz"}}, {a: "foo", b: { c: "bar"}})).toBe(false);
    });

    it("passes for Objects that are equivalent (with cycles)", function() {
      var actual = { a: "foo" },
        expected = { a: "foo" },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      actual.b = actual;
      expected.b = actual;

      expect(matchersUtil.equals(actual, expected)).toBe(true);
    });

    it("fails for Objects that are not equivalent (with cycles)", function() {
      var actual = { a: "foo" },
        expected = { a: "bar" },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      actual.b = actual;
      expected.b = actual;

      expect(matchersUtil.equals(actual, expected)).toBe(false);
    });

    it("fails for Objects that have the same number of keys, but different keys/values", function () {
      var expected = { a: undefined },
        actual = { b: 1 },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(actual, expected)).toBe(false);
    });

    it("fails when comparing an empty object to an empty array (issue #114)", function() {
      var emptyObject = {},
        emptyArray = [],
        matchersUtil = new jasmineUnderTest.MatchersUtil();


      expect(matchersUtil.equals(emptyObject, emptyArray)).toBe(false);
      expect(matchersUtil.equals(emptyArray, emptyObject)).toBe(false);
    });

    it("passes for equivalent frozen objects (GitHub issue #266)", function() {
      var a = { foo: 1 },
        b = {foo: 1 },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      Object.freeze(a);
      Object.freeze(b);

      expect(matchersUtil.equals(a,b)).toBe(true);
    });

    it("passes for equivalent Promises (GitHub issue #1314)", function() {
      if (typeof Promise === 'undefined') { return; }

      var p1 = new Promise(function () {}),
        p2 = new Promise(function () {}),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(p1, p1)).toBe(true);
      expect(matchersUtil.equals(p1, p2)).toBe(false);
    });

    describe("when running in a browser", function() {
      function isNotRunningInBrowser() {
        return typeof document === 'undefined'
      }

      it("passes for equivalent DOM nodes", function() {
        if (isNotRunningInBrowser()) {
          return;
        }
        var a = document.createElement("div");
        var matchersUtil = new jasmineUnderTest.MatchersUtil();

        a.setAttribute("test-attr", "attr-value");
        a.appendChild(document.createTextNode('test'));

        var b = document.createElement("div");
        b.setAttribute("test-attr", "attr-value");
        b.appendChild(document.createTextNode('test'));

        expect(matchersUtil.equals(a,b)).toBe(true);
      });

      it("passes for equivalent objects from different frames", function() {
        if (isNotRunningInBrowser()) {
          return;
        }
        var matchersUtil = new jasmineUnderTest.MatchersUtil();
        var iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.contentWindow.eval('window.testObject = {}');
        expect(matchersUtil.equals({}, iframe.contentWindow.testObject)).toBe(true);
        document.body.removeChild(iframe);
      });

      it("fails for DOM nodes with different attributes or child nodes", function() {
        if (isNotRunningInBrowser()) {
          return;
        }
        var matchersUtil = new jasmineUnderTest.MatchersUtil();
        var a = document.createElement("div");
        a.setAttribute("test-attr", "attr-value");
        a.appendChild(document.createTextNode('test'));

        var b = document.createElement("div");
        b.setAttribute("test-attr", "attr-value2");
        b.appendChild(document.createTextNode('test'));

        expect(matchersUtil.equals(a,b)).toBe(false);

        b.setAttribute("test-attr", "attr-value");
        expect(matchersUtil.equals(a,b)).toBe(true);

        b.appendChild(document.createTextNode('2'));
        expect(matchersUtil.equals(a,b)).toBe(false);

        a.appendChild(document.createTextNode('2'));
        expect(matchersUtil.equals(a,b)).toBe(true);
      });
    });

    describe("when running in Node", function() {
      function isNotRunningInNode() {
        return typeof require !== 'function'
      }

      it("passes for equivalent objects from different vm contexts", function() {
        if (isNotRunningInNode()) {
          return;
        }
        var matchersUtil = new jasmineUnderTest.MatchersUtil();
        var vm = require('vm');
        var sandbox = {
          obj: null
        };
        vm.runInNewContext('obj = {a: 1, b: 2}', sandbox);

        expect(matchersUtil.equals(sandbox.obj, {a: 1, b: 2})).toBe(true);
      });

      it("passes for equivalent arrays from different vm contexts", function() {
        if (isNotRunningInNode()) {
          return;
        }
        var matchersUtil = new jasmineUnderTest.MatchersUtil();
        var vm = require('vm');
        var sandbox = {
          arr: null
        };
        vm.runInNewContext('arr = [1, 2]', sandbox);

        expect(matchersUtil.equals(sandbox.arr, [1, 2])).toBe(true);
      });
    });

    it("passes when Any is used", function() {
      var number = 3,
        anyNumber = new jasmineUnderTest.Any(Number),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(number, anyNumber)).toBe(true);
      expect(matchersUtil.equals(anyNumber, number)).toBe(true);
    });

    it("fails when Any is compared to something unexpected", function() {
      var number = 3,
        anyString = new jasmineUnderTest.Any(String),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(number, anyString)).toBe(false);
      expect(matchersUtil.equals(anyString, number)).toBe(false);
    });

    it("passes when ObjectContaining is used", function() {
      var obj = {
        foo: 3,
        bar: 7
      },
        containing = new jasmineUnderTest.ObjectContaining({foo: 3}),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(obj, containing)).toBe(true);
      expect(matchersUtil.equals(containing, obj)).toBe(true);
    });

    it("passes when MapContaining is used", function() {
      jasmine.getEnv().requireFunctioningMaps();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var obj = new Map();
      obj.set(1, 2);
      obj.set('foo', 'bar');
      var containing = new jasmineUnderTest.MapContaining(new Map());
      containing.sample.set('foo', 'bar');

      expect(matchersUtil.equals(obj, containing)).toBe(true);
      expect(matchersUtil.equals(containing, obj)).toBe(true);
    });

    it("passes when SetContaining is used", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var obj = new Set();
      obj.add(1);
      obj.add('foo');
      var containing = new jasmineUnderTest.SetContaining(new Set());
      containing.sample.add(1);

      expect(matchersUtil.equals(obj, containing)).toBe(true);
      expect(matchersUtil.equals(containing, obj)).toBe(true);
    });

    it("passes when an asymmetric equality tester returns true", function() {
      var tester = { asymmetricMatch: function(other) { return true; } },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(false, tester)).toBe(true);
      expect(matchersUtil.equals(tester, false)).toBe(true);
    });

    it("fails when an asymmetric equality tester returns false", function() {
      var tester = { asymmetricMatch: function(other) { return false; } },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(true, tester)).toBe(false);
      expect(matchersUtil.equals(tester, true)).toBe(false);
    });

    it("passes when ArrayContaining is used", function() {
      var arr = ["foo", "bar"],
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(arr, new jasmineUnderTest.ArrayContaining(["bar"]))).toBe(true);
    });

    it("passes when a custom equality matcher passed to equals returns true", function() {
      // TODO: remove this in the next major release.
      var tester = function(a, b) { return true; },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(1, 2, [tester])).toBe(true);
    });

    it("passes when a custom equality matcher passed to the constructor returns true", function() {
      var tester = function(a, b) { return true; },
        matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [tester]});

      expect(matchersUtil.equals(1, 2)).toBe(true);
    });

    it("passes for two empty Objects", function () {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals({}, {})).toBe(true);
    });

    describe("when a custom equality matcher is passed to equals that returns 'undefined'", function () {
      // TODO: remove this in the next major release.
      var tester = function(a, b) { return jasmine.undefined; };

      it("passes for two empty Objects", function () {
        var matchersUtil = new jasmineUnderTest.MatchersUtil();
        expect(matchersUtil.equals({}, {}, [tester])).toBe(true);
      });
    });

    describe("when a custom equality matcher is passed to the constructor that returns 'undefined'", function () {
      var tester = function(a, b) { return jasmine.undefined; };

      it("passes for two empty Objects", function () {
        var matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [tester]});
        expect(matchersUtil.equals({}, {})).toBe(true);
      });
    });

    it("fails for equivalents when a custom equality matcher passed to equals returns false", function() {
      // TODO: remove this in the next major release.
      var tester = function(a, b) { return false; },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(1, 1, [tester])).toBe(false);
    });

    it("fails for equivalents when a custom equality matcher passed to the constructor returns false", function() {
      var tester = function(a, b) { return false; },
        matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [tester]});

      expect(matchersUtil.equals(1, 1)).toBe(false);
    });

    it("passes for an asymmetric equality tester that returns true when a custom equality tester passed to equals return false", function() {
      // TODO: remove this in the next major release.
      var asymmetricTester = { asymmetricMatch: function(other) { return true; } },
        symmetricTester = function(a, b) { return false; },
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(asymmetricTester, true, [symmetricTester])).toBe(true);
      expect(matchersUtil.equals(true, asymmetricTester, [symmetricTester])).toBe(true);
    });

    it("passes for an asymmetric equality tester that returns true when a custom equality tester passed to the constructor return false", function() {
      var asymmetricTester = { asymmetricMatch: function(other) { return true; } },
        symmetricTester = function(a, b) { return false; },
        matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [symmetricTester()]});

      expect(matchersUtil.equals(asymmetricTester, true)).toBe(true);
      expect(matchersUtil.equals(true, asymmetricTester)).toBe(true);
    });

    describe("The compatibility shim passed to asymmetric equality testers", function() {
      describe("When equals is called with custom equality testers", function() {
        it("is both a matchersUtil and the custom equality testers passed to equals", function() {
          var asymmetricTester = jasmine.createSpyObj('tester', ['asymmetricMatch']),
            symmetricTester = function() { } ,
            matchersUtil = new jasmineUnderTest.MatchersUtil(),
            shim;

          matchersUtil.equals(true, asymmetricTester, [symmetricTester]);
          shim = asymmetricTester.asymmetricMatch.calls.argsFor(0)[1];
          expect(shim).toEqual(jasmine.any(jasmineUnderTest.MatchersUtil));
          expect(shim.length).toEqual(1);
          expect(shim[0]).toEqual(symmetricTester);
        });
      });

      describe("When equals is called with custom equality testers", function() {
        it("is both a matchersUtil and the custom equality testers passed to the constructor", function() {
          var asymmetricTester = jasmine.createSpyObj('tester', ['asymmetricMatch']),
            symmetricTester = function() { } ,
            matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [symmetricTester]}),
            shim;

          matchersUtil.equals(true, asymmetricTester);
          shim = asymmetricTester.asymmetricMatch.calls.argsFor(0)[1];
          expect(shim).toEqual(jasmine.any(jasmineUnderTest.MatchersUtil));
          expect(shim.length).toEqual(1);
          expect(shim[0]).toEqual(symmetricTester);
        });
      });
    });

    it("passes when an Any is compared to an Any that checks for the same type", function() {
      var any1 = new jasmineUnderTest.Any(Function),
        any2 = new jasmineUnderTest.Any(Function),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      expect(matchersUtil.equals(any1, any2)).toBe(true);
    });

    it("passes for null prototype objects with same properties", function () {
      var objA = Object.create(null),
        objB = Object.create(null),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      objA.name = 'test';
      objB.name = 'test';

      expect(matchersUtil.equals(objA, objB)).toBe(true);
    });

    it("fails for null prototype objects with different properties", function () {
      var objA = Object.create(null),
        objB = Object.create(null),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      objA.name = 'test';
      objB.test = 'name';

      expect(matchersUtil.equals(objA, objB)).toBe(false);
    });

    it("passes when comparing two empty sets", function() {
      jasmine.getEnv().requireFunctioningSets();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Set(), new Set())).toBe(true);
    });

    it("passes when comparing identical sets", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA = new Set();
      setA.add(6);
      setA.add(5);
      var setB = new Set();
      setB.add(6);
      setB.add(5);

      expect(matchersUtil.equals(setA, setB)).toBe(true);
    });

    it("passes when comparing identical sets with different insertion order and simple elements", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA = new Set();
      setA.add(3);
      setA.add(6);
      var setB = new Set();
      setB.add(6);
      setB.add(3);

      expect(matchersUtil.equals(setA, setB)).toBe(true);
    });

    it("passes when comparing identical sets with different insertion order and complex elements 1", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA1 = new Set();
      setA1.add(['a',3]);
      setA1.add([6,1]);
      var setA2 = new Set();
      setA1.add(['y',3]);
      setA1.add([6,1]);
      var setA = new Set();
      setA.add(setA1);
      setA.add(setA2);


      var setB1 = new Set();
      setB1.add([6,1]);
      setB1.add(['a',3]);
      var setB2 = new Set();
      setB1.add([6,1]);
      setB1.add(['y',3]);
      var setB = new Set();
      setB.add(setB1);
      setB.add(setB2);

      expect(matchersUtil.equals(setA, setB)).toBe(true);
    });

    it("passes when comparing identical sets with different insertion order and complex elements 2", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA = new Set();
      setA.add([[1,2], [3,4]]);
      setA.add([[5,6], [7,8]]);
      var setB = new Set();
      setB.add([[5,6], [7,8]]);
      setB.add([[1,2], [3,4]]);

      expect(matchersUtil.equals(setA, setB)).toBe(true);
    });

    it("fails for sets with different elements", function() {
      jasmine.getEnv().requireFunctioningSets();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA = new Set();
      setA.add(6);
      setA.add(3);
      setA.add(5);
      var setB = new Set();
      setB.add(6);
      setB.add(4);
      setB.add(5);

      expect(matchersUtil.equals(setA, setB)).toBe(false);
    });

    it("fails for sets of different size", function() {
      jasmine.getEnv().requireFunctioningSets();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setA = new Set();
      setA.add(6);
      setA.add(3);
      var setB = new Set();
      setB.add(6);
      setB.add(4);
      setB.add(5);

      expect(matchersUtil.equals(setA, setB)).toBe(false);
    });

    it("passes when comparing two empty maps", function() {
      jasmine.getEnv().requireFunctioningMaps();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.equals(new Map(), new Map())).toBe(true);
    });

    it("passes when comparing identical maps", function() {
      jasmine.getEnv().requireFunctioningMaps();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var mapA = new Map();
      mapA.set(6, 5);
      var mapB = new Map();
      mapB.set(6, 5);
      expect(matchersUtil.equals(mapA, mapB)).toBe(true);
    });

    it("passes when comparing identical maps with different insertion order", function() {
      jasmine.getEnv().requireFunctioningMaps();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var mapA = new Map();
      mapA.set("a", 3);
      mapA.set(6, 1);
      var mapB = new Map();
      mapB.set(6, 1);
      mapB.set("a", 3);
      expect(matchersUtil.equals(mapA, mapB)).toBe(true);
    });

    it("fails for maps with different elements", function() {
      jasmine.getEnv().requireFunctioningMaps();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var mapA = new Map();
      mapA.set(6, 3);
      mapA.set(5, 1);
      var mapB = new Map();
      mapB.set(6, 4);
      mapB.set(5, 1);

      expect(matchersUtil.equals(mapA, mapB)).toBe(false);
    });

    it("fails for maps of different size", function() {
      jasmine.getEnv().requireFunctioningMaps();
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var mapA = new Map();
      mapA.set(6, 3);
      var mapB = new Map();
      mapB.set(6, 4);
      mapB.set(5, 1);
      expect(matchersUtil.equals(mapA, mapB)).toBe(false);
    });

    describe("when running in an environment with array polyfills", function() {
      var findIndexDescriptor = Object.getOwnPropertyDescriptor(Array.prototype, 'findIndex');
      if (!findIndexDescriptor) {
        return;
      }

      beforeEach(function() {
        Object.defineProperty(Array.prototype, 'findIndex', {
          enumerable: true,
          value: function (predicate) {
            if (this === null) {
              throw new TypeError('Array.prototype.findIndex called on null or undefined');
            }

            if (typeof predicate !== 'function') {
              throw new TypeError('predicate must be a function');
            }

            var list = Object(this);
            var length = list.length >>> 0;
            var thisArg = arguments[1];
            var value;

            for (var i = 0; i < length; i++) {
              value = list[i];
              if (predicate.call(thisArg, value, i, list)) {
                return i;
              }
            }

            return -1;
          }
        });
      });

      afterEach(function() {
        Object.defineProperty(Array.prototype, 'findIndex', findIndexDescriptor);
      });

      it("passes when there's an array polyfill", function() {
        expect(['foo']).toEqual(['foo']);
      });
    });

    it('uses a diffBuilder if one is provided as the fourth argument', function() {
      // TODO: remove this in the next major release.
      var diffBuilder = new jasmineUnderTest.DiffBuilder(),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      spyOn(diffBuilder, 'record');
      spyOn(diffBuilder, 'withPath').and.callThrough();

      matchersUtil.equals([1], [2], [], diffBuilder);
      expect(diffBuilder.withPath).toHaveBeenCalledWith('length', jasmine.any(Function));
      expect(diffBuilder.withPath).toHaveBeenCalledWith(0, jasmine.any(Function));
      expect(diffBuilder.record).toHaveBeenCalledWith(1, 2);
    });

    it('uses a diffBuilder if one is provided as the third argument', function() {
      var diffBuilder = new jasmineUnderTest.DiffBuilder(),
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      spyOn(diffBuilder, 'record');
      spyOn(diffBuilder, 'withPath').and.callThrough();

      matchersUtil.equals([1], [2], diffBuilder);
      expect(diffBuilder.withPath).toHaveBeenCalledWith('length', jasmine.any(Function));
      expect(diffBuilder.withPath).toHaveBeenCalledWith(0, jasmine.any(Function));
      expect(diffBuilder.record).toHaveBeenCalledWith(1, 2);
    });
  });

  describe("contains", function() {
    it("passes when expected is a substring of actual", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains("ABC", "BC")).toBe(true);
    });

    it("fails when expected is a not substring of actual", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains("ABC", "X")).toBe(false);
    });

    it("passes when expected is an element in an actual array", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains(['foo', 'bar'], 'foo')).toBe(true);
    });

    it("fails when expected is not an element in an actual array", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains(['foo', 'bar'], 'baz')).toBe(false);
    });

    it("passes with mixed-element arrays", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains(["foo", {some: "bar"}], "foo")).toBe(true);
      expect(matchersUtil.contains(["foo", {some: "bar"}], {some: "bar"})).toBe(true);
    });

    it("uses custom equality testers if passed to contains and actual is an Array", function() {
      // TODO: remove this in the next major release.
      var customTester = function(a, b) {return true;},
        matchersUtil = new jasmineUnderTest.MatchersUtil();

        expect(matchersUtil.contains([1, 2], 3, [customTester])).toBe(true);
    });

    it("uses custom equality testers if passed to the constructor and actual is an Array", function() {
      var customTester = function(a, b) {return true;},
        matchersUtil = new jasmineUnderTest.MatchersUtil({customTesters: [customTester]});

      expect(matchersUtil.contains([1, 2], 3)).toBe(true);
    });

    it("fails when actual is undefined", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains(undefined, 'A')).toBe(false);
    });

    it("fails when actual is null", function() {
      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      expect(matchersUtil.contains(null, 'A')).toBe(false);
    });

    it("passes with array-like objects", function() {
      var capturedArgs = null,
        matchersUtil = new jasmineUnderTest.MatchersUtil();

      function testFunction(){
        capturedArgs = arguments;
      }

      testFunction('foo', 'bar');
      expect(matchersUtil.contains(capturedArgs, 'bar')).toBe(true);
    });

    it("passes for set members", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var setItem = {'foo': 'bar'};
      var set = new Set();
      set.add(setItem);

      expect(matchersUtil.contains(set, setItem)).toBe(true);
    });

    // documenting current behavior
    it("fails (!) for objects that equal to a set member", function() {
      jasmine.getEnv().requireFunctioningSets();

      var matchersUtil = new jasmineUnderTest.MatchersUtil();
      var set = new Set();
      set.add({'foo': 'bar'});

      expect(matchersUtil.contains(set, {'foo': 'bar'})).toBe(false);
    });
  });

  describe("buildMessage", function() {

    it("builds an English sentence for a failure case", function() {
      var actual = "foo",
        name = "toBar",
        matchersUtil = new jasmineUnderTest.MatchersUtil(),
        message = matchersUtil.buildFailureMessage(name, false, actual);

      expect(message).toEqual("Expected 'foo' to bar.");
    });

    it("builds an English sentence for a 'not' failure case", function() {
      var actual = "foo",
        name = "toBar",
        isNot = true,
        matchersUtil = new jasmineUnderTest.MatchersUtil(),
        message = message = matchersUtil.buildFailureMessage(name, isNot, actual);

      expect(message).toEqual("Expected 'foo' not to bar.");
    });

    it("builds an English sentence for an arbitrary array of expected arguments", function() {
      var actual = "foo",
        name = "toBar",
        matchersUtil = new jasmineUnderTest.MatchersUtil(),
        message = matchersUtil.buildFailureMessage(name, false, actual, "quux", "corge");

      expect(message).toEqual("Expected 'foo' to bar 'quux', 'corge'.");
    });
  });
});