Introduce matchers#toBeInstanceOf

spec/core/matchers/toBeInstanceOfSpec.js

@@ -0,0 +1,235 @@
+describe('toBeInstanceOf', function() {
+  function setPrototypeOf(object, proto) {
+    // Support older environments
+    Object.setPrototypeOf ? Object.setPrototypeOf(object, proto) : object.__proto__ = proto;
+  }
+
+  describe('when expecting Number', function() {
+    it('passes for literal number', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(3, Number);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Number not to be an instance of Number'
+      });
+    });
+
+    it('passes for NaN', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(NaN, Number);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of NaN not to be an instance of Number'
+      });
+    });
+
+    it('passes for Infinity', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(Infinity, Number);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Number not to be an instance of Number'
+      });
+    });
+
+    it('fails for a non-number', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare('foo', Number);
+      expect(result).toEqual({
+        pass: false,
+        message: 'Expected instance of String to be an instance of Number'
+      });
+    });
+  });
+
+  describe('when expecting String', function() {
+    it('passes for a string', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare('foo', String);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of String not to be an instance of String'
+      });
+    });
+
+    it('fails for a non-string', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare({}, String);
+      expect(result).toEqual({
+        pass: false,
+        message: 'Expected instance of Object to be an instance of String'
+      });
+    });
+  });
+
+  describe('when expecting Boolean', function() {
+    it('passes for a boolean', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(true, Boolean);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Boolean not to be an instance of Boolean'
+      });
+    });
+
+    it('fails for a non-boolean', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare('false', Boolean);
+      expect(result).toEqual({
+        pass: false,
+        message: 'Expected instance of String to be an instance of Boolean'
+      });
+    });
+  });
+
+  describe('when expecting RegExp', function() {
+    it('passes for a literal regular expression', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(/foo/, RegExp);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of RegExp not to be an instance of RegExp'
+      });
+    });
+  });
+
+  describe('when expecting Function', function() {
+    it('passes for a function', function() {
+      var fn = function() { };
+
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(fn, Function);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Function not to be an instance of Function'
+      });
+    });
+
+    it('passes for an async function', function() {
+      jasmine.getEnv().requireAsyncAwait();
+
+      var fn = eval("(async function fn() { return 'foo'; })");
+      console.log(fn);
+
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(fn, Function);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of AsyncFunction not to be an instance of Function'
+      });
+    });
+  });
+
+  describe('when expecting Object', function() {
+    function Animal() { }
+
+    it('passes for any object', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare({ foo: 'bar' }, Object);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Object not to be an instance of Object'
+      });
+    });
+
+    it('passes for an Error object', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(new Error('example'), Object);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Error not to be an instance of Object'
+      });
+    });
+
+    it('passes for a user-defined class', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(new Animal(), Object);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Animal not to be an instance of Object'
+      });
+    });
+
+    it('fails for a non-object', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare('foo', Object);
+      expect(result).toEqual({
+        pass: false,
+        message: 'Expected instance of String to be an instance of Object'
+      });
+    });
+
+    it('passes for objects with no constructor', function() {
+      var object = {};
+      setPrototypeOf(object, null);
+
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(object, Object);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of null({  }) not to be an instance of Object'
+      });
+    });
+  });
+
+  describe('when expecting a user-defined class', function() {
+    // Base class
+    function Animal() { }
+
+    // Subclasses, defined using syntax that is as old as possible
+    function Dog() {
+      Animal.call(this);
+    }
+    Dog.prototype = new Animal();
+    Dog.prototype.constructor = Dog;
+
+    function Cat() {
+      Animal.call(this);
+    }
+    Cat.prototype = new Animal();
+    Cat.prototype.constructor = Cat;
+
+    it('passes for instances of that class', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(new Animal(), Animal);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Animal not to be an instance of Animal'
+      });
+    });
+
+    it('passes for instances of a subclass', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(new Cat(), Animal);
+      expect(result).toEqual({
+        pass: true,
+        message: 'Expected instance of Cat not to be an instance of Animal'
+      });
+    });
+
+    it('does not pass for sibling classes', function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      var result = matcher.compare(new Dog(), Cat);
+      expect(result).toEqual({
+        pass: false,
+        message: 'Expected instance of Dog to be an instance of Cat'
+      });
+    });
+  });
+
+  it('raises an error if passed an invalid expected value', function() {
+    expect(function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      matcher.compare({}, 'Error');
+    }).toThrowError('<toBeInstanceOf> : Expected value is not a constructor function\n' +
+        'Usage: expect(value).toBeInstanceOf(<ConstructorFunction>)');
+  });
+
+  it('raises an error if missing an expected value', function() {
+    expect(function() {
+      var matcher = jasmineUnderTest.matchers.toBeInstanceOf();
+      matcher.compare({}, undefined);
+    }).toThrowError('<toBeInstanceOf> : Expected value is not a constructor function\n' +
+        'Usage: expect(value).toBeInstanceOf(<ConstructorFunction>)');
+  });
+});

src/core/matchers/requireMatchers.js

@@ -4,6 +4,7 @@ getJasmineRequireObj().requireMatchers = function(jRequire, j$) {
       'toBe',
       'toBeCloseTo',
       'toBeDefined',
+      'toBeInstanceOf',
       'toBeFalse',
       'toBeFalsy',
       'toBeGreaterThan',

src/core/matchers/toBeInstanceOf.js

@@ -0,0 +1,45 @@
+getJasmineRequireObj().toBeInstanceOf = function(j$) {
+  var usageError =  j$.formatErrorMsg('<toBeInstanceOf>', 'expect(value).toBeInstanceOf(<ConstructorFunction>)');
+
+  /**
+   * {@link expect} the actual to be an instance of the expected class
+   * @function
+   * @name matchers#toBeInstanceOf
+   * @param {Object} expected - The class or constructor function to check for
+   * @example
+   * expect('foo').toBeInstanceOf(String);
+   * expect(3).toBeInstanceOf(Number);
+   * expect(new Error()).toBeInstanceOf(Error);
+   */
+  function toBeInstanceOf(util, customEqualityTesters) {
+    return {
+      compare: function(actual, expected) {
+        var actualType = actual && actual.constructor ? j$.fnNameFor(actual.constructor) : j$.pp(actual),
+            expectedType = expected ? j$.fnNameFor(expected) : j$.pp(expected),
+            expectedMatcher,
+            pass;
+
+        try {
+            expectedMatcher = new j$.Any(expected);
+            pass = expectedMatcher.asymmetricMatch(actual);
+        } catch (error) {
+            throw new Error(usageError('Expected value is not a constructor function'));
+        }
+
+        if (pass) {
+          return {
+            pass: true,
+            message: 'Expected instance of ' + actualType + ' not to be an instance of ' + expectedType
+          };
+        } else {
+          return {
+            pass: false,
+            message: 'Expected instance of ' + actualType + ' to be an instance of ' + expectedType
+          };
+        }
+      }
+    };
+  }
+
+  return toBeInstanceOf;
+};