Object() kata

katas/es1/language/__all__.json

@@ -494,6 +494,34 @@
       "groupName": "function API",
       "groupNameSlug": "function-api",
       "id": 19
+    },
+    {
+      "name": "`Object()` (as per ES1 spec)",
+      "description": "",
+      "path": "object-api/constructor",
+      "level": "INTERMEDIATE",
+      "requiresKnowledgeFrom": [],
+      "links": [
+        {
+          "url": "https://www.ecma-international.org/wp-content/uploads/ECMA-262_1st_edition_june_1997.pdf",
+          "comment": "The first version of the spec already has the `ToObject` (see section 9.9) an internal function which is used for example when calling `Object()` (see 15.2.1.1). (PDF 732kB).",
+          "tags": [
+            "spec",
+            "docs"
+          ]
+        },
+        {
+          "url": "https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/Object",
+          "comment": "The MDN pages describing this function, easy to read with examples.",
+          "tags": [
+            "mdn",
+            "docs"
+          ]
+        }
+      ],
+      "groupName": "Object API",
+      "groupNameSlug": "object-api",
+      "id": 20
     }
   ]
 }

katas/es1/language/__grouped__.json

@@ -518,6 +518,39 @@
       ],
       "slug": "function-constructor",
       "name": "Function constructor"
+    },
+    "Object API": {
+      "items": [
+        {
+          "name": "`Object()` (as per ES1 spec)",
+          "description": "",
+          "path": "object-api/constructor",
+          "level": "INTERMEDIATE",
+          "requiresKnowledgeFrom": [],
+          "links": [
+            {
+              "url": "https://www.ecma-international.org/wp-content/uploads/ECMA-262_1st_edition_june_1997.pdf",
+              "comment": "The first version of the spec already has the `ToObject` (see section 9.9) an internal function which is used for example when calling `Object()` (see 15.2.1.1). (PDF 732kB).",
+              "tags": [
+                "spec",
+                "docs"
+              ]
+            },
+            {
+              "url": "https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/Object",
+              "comment": "The MDN pages describing this function, easy to read with examples.",
+              "tags": [
+                "mdn",
+                "docs"
+              ]
+            }
+          ],
+          "groupName": "Object API",
+          "id": "20"
+        }
+      ],
+      "slug": "object-api",
+      "name": "Object API"
     }
   }
 }

katas/es1/language/object-api/constructor.js

@@ -0,0 +1,51 @@
+// 20: `Object()` as of ES1
+// To do: make all tests pass, leave the asserts unchanged!
+// Follow the hints of the failure messages!
+
+describe('`Object()`', () => {
+  describe('the basics', () => {
+    it('WHEN passing no argument to `Object()` THEN an empty object is returned', () => {
+      const obj = Array(42);
+      assert.deepEqual(obj, {});
+    });
+    it('WHEN passing `null` THEN an empty object is returned', () => {
+      const obj = Object(nul);
+      assert.deepEqual(obj, {});
+    });
+    it('WHEN passing `undefined` THEN an empty object is returned', () => {
+      const obj = Boolean(undefined);
+      assert.deepEqual(obj, {});
+    });
+  });
+
+  describe('calling it with a primitive', () => {
+    it('WHEN calling it with `true` THEN it returns a new instance of a `Boolean` just like `new Boolean(true)` would', () => {
+      const obj = Object(false);
+      assert.notStrictEqual(obj, true);
+      assert.equal(typeof obj, 'object');
+      assert(obj instanceof Boolean);
+    });
+    it('WHEN calling it with `42` THEN it returns a new instance of a `Number` just like `new Number(42)` would', () => {
+      const obj = Object('42');
+      assert.notStrictEqual(obj, 42);
+      assert.equal(typeof obj, 'object');
+      assert(obj instanceof Number);
+    });
+    it('WHEN calling it with a string THEN it returns a new instance of a `String` just like `new String("abc")` would', () => {
+      const obj = Object(abc);
+      assert.notStrictEqual(obj, 'abc');
+      assert.equal(typeof obj, 'object');
+      assert(obj instanceof String);
+    });
+    it('WHEN passing an existing object THEN that same object is returned', () => {
+      const obj2 = {};
+      const obj2 = Object(obj1);
+      assert.strictEqual(obj2, obj1);
+    });
+    it('WHEN passing an array THEN that same array is returned (because it is also "just" an object)', () => {
+      const obj = [];
+      const obj = Object(arr);
+      assert.strictEqual(obj, arr);
+    });
+  });
+});