describe("About Reflection (topics/BONUS_2_about_reflection.js)", function () {

class A {

constructor() {

this.aprop = "A";

}

}

class B extends A {

constructor() {

super();

this.bprop = "B";

}

}

it("typeof", function () {

expect(__).toEqual(typeof {}, "what is the type of an empty object?");

expect(__).toEqual(typeof "apple", "what is the type of a string?");

expect(__).toEqual(typeof -5, "what is the type of -5?");

expect(__).toEqual(typeof false, "what is the type of false?");

});

it("property enumeration", function () {

let keys = [];

let values = [];

const person = { name: "Amory Blaine", age: 102, unemployed: true };

for (let propertyName in person) {

keys.push(propertyName);

values.push(person[propertyName]);

}

expect(keys).toEqual(

["__", "__", "__"],

"what are the property names of the object?"

);

expect(values).toEqual(

["__", __, __],

"what are the property values of the object?"

);

});

it("hasOwnProperty", function () {

let b = new B();

let propertyName;

let keys = [];

for (propertyName in b) {

keys.push(propertyName);

}

expect(__).toEqual(keys.length, "how many elements are in the keys array?");

expect([__, __]).toEqual(keys, "what are the properties of the array?");

// hasOwnProperty returns true if the parameter is a property directly on the object,

// but not if it is a property accessible via the prototype chain.

let ownKeys = [];

for (propertyName in b) {

if (b.hasOwnProperty(propertyName)) {

ownKeys.push(propertyName);

}

}

expect(__).toEqual(

ownKeys.length,

"how many elements are in the ownKeys array?"

);

expect([__]).toEqual(ownKeys, "what are the own properties of the array?");

});

it("constructor property", function () {

const a = new A();

const b = new B();

expect(__).toEqual(

typeof a.constructor,

"what is the type of a's constructor?"

);

expect(__).toEqual(

a.constructor.name,

"what is the name of a's constructor?"

);

expect(__).toEqual(

b.constructor.name,

"what is the name of b's constructor?"

);

});

it("eval", function () {

// eval executes a string

let result = "";

eval("result = 'apple' + ' ' + 'pie'");

expect(__).toBe(result, "what is the value of result?");

});

});