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​​[archive] JS Live Class Day 1: Activities

​​Environment

​​Download, install, and setup Node.js.

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​​Launch the REPL and ensure you can run some commands

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​​Finally, download the code and get it running.

​​Test-Driven Development

​​Writing really solid unit tests is a non-negotiable skill for an engineer to master. Unfortunately, they are also shrouded in mystery. Take a look at the following resources to understand the rationale behind my testing setup:

• ​​Five Questions Every Unit Test Must Answer

• ​​Why I Use Tape Instead of Mocha and So Should You

• ​​Five Misconceptions About TDD & Unit Tests

​​Learn about Constructors and Prototypes

​​Create a constructor function and a prototype for an Animal​ .

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​​Here’s a test to try to make pass:

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​​const animal = new Animal();

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​​test.ok( animal instanceof Animal, 'should create an instance of Animal' );

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​​Create a function on Animal​ ‘s prototype called speak​  that returns the animal’s sound.

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​​const animal = new Animal();

​​const expected = 'generic sound';

​​const actual = animal.speak();

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​​test.equal( actual, expected, 'should make a generic sound when it speaks' );

​​Inheritance

​​Create two new constructors with prototypes that inherit from Animal​: Reptile​ and Primate​.  Overwrite the speak​  method for each.

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​​let actual, expected;

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​​const reptile = new Reptile();

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​​test.ok( reptile instanceof Reptile, 'should be an instance of Reptile' );

​​test.ok( reptile instanceof Animal, 'should be an instance of Animal' );

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​​expected = Reptile.SOUND;

​​actual = reptile.speak();

​​test.equal( actual, expected, 'should make a reptile sound when it speaks' );

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​​const primate = new Primate();

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​​test.ok( primate instanceof Primate, 'should be an instance of Primate' );

​​test.ok( primate instanceof Animal, 'should be an instance of Animal' );

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​​expected = Primate.SOUND;

​​actual = primate.speak();

​​test.equal( actual, expected, 'should make a primate sound when it speaks' );