Part1 - constructors and prototypes

README.md

@@ -1,25 +1,3 @@
-# Test Framework
-
-An empty project with Tape to demonstrate proper unit test writing. Part of a recent Intro to
-JavaScript class I taught.
-
-## Running
-
-Follow the usual procedure for setting up NPM:
-
-```sh
-$ npm install
-````
-
-And then run the unit tests via NPM scripts:
-
-```sh
-$ npm test
-# or npm run test
-```
-
-## Files
-
-Any file ending in `spec.js` anywhere within the source folder will be included in the running
-tests. For an example, check out `src/spec.js`, which tests `src/index.js`.
+# Hello
 
+Questions and thoughs are in the comments.

src/index.js

@@ -1,26 +1,28 @@
-export function double ( x ) {
-  return x * 2;
-}
-
-export function doubleXTimes ( x, num ) {
-  let result = x;
 
-  for ( let i = 1; i <= num; i++ ) {
-    // result = result * 2;
-    result = double( result );
-  }
-
-  return result;
+const Animal = function() {};
+Animal.prototype = function() {};
+Animal.prototype.speak = function() {
+  return 'generic sound';
 }
 
-export function doubleEach ( arr ) {
-  let result = arr.map( double );
+const Reptile = function() {};
+Reptile.prototype = Object.create(Animal.prototype);
+Reptile.SOUND = 'Slither slither';
+Reptile.prototype.speak = function(sound = Reptile.SOUND) {
+  return Reptile.SOUND;
+};
 
-  // const result = arr.map( x => double( x ) );
-  // const result = arr.map( function ( x ) {
-  //   return double( x );
-  // });
+const Primate = function() {};
+Primate.prototype = Object.create(Animal.prototype);
+Primate.SOUND = 'Ug ug';
+Primate.prototype.speak = function(sound = Primate.SOUND) {
+  return Primate.SOUND;
+};
 
-  return result;
-}
+const Human = function() {};
+Human.prototype = Object.create(Primate.prototype);
+Human.prototype.speak = function(sound) {
+  return sound;
+};
 
+export { Animal, Reptile, Primate, Human };

src/spec.js

@@ -1,30 +1,76 @@
 import test from 'tape';
-import { double, doubleXTimes, doubleEach } from './index';
+import { Animal, Reptile, Primate, Human } from './index';
 
-test( 'double fn', function ( test ) {
-  const actual = double( 5 );
-  const expected = 10;
 
-  test.equal( actual, expected, 'should double the value' );
+
+test('Create a constructor function and a prototype for an Animal', function(test) {
+
+  const animal = new Animal();
+
+  test.ok( animal instanceof Animal, 'should create an instance of Animal' );
 
   test.end();
 });
 
-test( 'doubleXTimes', function ( test ) {
-  const actual = doubleXTimes( 5, 3 );
-  const expected = 40;
 
-  test.equal( actual, expected, 'should double 5 three times' );
+
+test('Create a function on Animal ‘s prototype called speak  that returns the animal’s sound.', function(test) {
+
+  const animal = new Animal();
+  const expected = 'generic sound';
+  const actual = animal.speak();
+
+  test.equal( actual, expected, 'should make a generic sound when it speaks' );
 
   test.end();
 });
 
-test( 'doubleEach', function ( test ) {
-  const actual = doubleEach([ 0, 1, 2 ]);
-  const expected = [ 0, 2, 4 ];
 
-  test.deepEqual( actual, expected, 'should double each in the array' );
 
+test('Create two new constructors with prototypes that inherit from Animal: Reptile and Primate.  Overwrite the speak  method for each.', function(test) {
+
+  let actual, expected;
+
+  const reptile = new Reptile();
+
+  test.ok( reptile instanceof Reptile, 'should be an instance of Reptile' );
+  test.ok( reptile instanceof Animal, 'should be an instance of Animal' );
+
+  expected = Reptile.SOUND;
+
+  actual = reptile.speak();
+  console.log(`* Reptile says, "${actual}"`);
+  test.equal( actual, expected, 'should make a reptile sound when it speaks' );
+
+  const primate = new Primate();
+
+  test.ok( primate instanceof Primate, 'should be an instance of Primate' );
+  test.ok( primate instanceof Animal, 'should be an instance of Animal' );
+
+  expected = Primate.SOUND;
+  actual = primate.speak();
+  console.log(`* Primate, says, "${actual}"`);
+  test.equal( actual, expected, 'should make a primate sound when it speaks' );
   test.end();
 });
 
+
+
+test('Create one more that inherits from Primate called Human.', function(test) {
+
+  let actual, expected;
+
+  const human = new Human();
+
+  test.ok( human instanceof Human, 'should be an instance of Human' );
+  test.ok( human instanceof Primate, 'should be an instance of Primate' );
+  test.ok( human instanceof Animal, 'should be an instance of Animal' );
+
+  const message = 'Hello';
+  expected = message;
+  actual = human.speak( message );
+  console.log(`* Human says, "${actual}"`);
+  test.equal( actual, expected, 'should speak what it is asked to speak' );
+
+  test.end();
+});