An exciting intro to Javascript unit testing Juan Lizarazo @juanlizarazog 2019 UtahJS Conference 

Hi I am Juan Lizarazo @juanlizarazog 

No, this talk is not about AMP :) Still, check it out at https://amp.dev 

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An exciting intro to Javascript unit testing @juanlizarazog 

Unit testing is a software testing method by which individual units of source code, sets of one or more computer program modules together with associated control data, usage procedures, and operating procedures, are tested to determine whether they are fit for use. @juanlizarazog 

How to make unit testing exciting? @juanlizarazog 

Let’s face it:
 
 Unit testing is boring! @juanlizarazog 

But learning about it doesn’t have to be! @juanlizarazog 

•Testing individual units of code • Unit is the smallest testable part What is unit testing? @juanlizarazog 

•Trust changes you make on existing (already tested) code. •Code quality •Changes occur quickly •Documents your own code •Automation Why? @juanlizarazog 

How do we unit test JavaScript? @juanlizarazog 

1. Pick a library or framework @juanlizarazog 

2. Learn some core concepts @juanlizarazog 

1. Learn some key concepts @juanlizarazog @juanlizarazog Expectations •Test the state of the code expect(1 + 1).toBe(2); 

1. Learn some key concepts @juanlizarazog @juanlizarazog Matchers •It’s just a function •Implements a boolean comparison expect(1 + 1).toBe(2); 

1. Learn some key concepts @juanlizarazog @juanlizarazog Specs •Short of specification •Group of expectations (that test the state of the code). •spec -> test test('adds 1 + 1 to equal 2', () => {
 expect(sum(1, 1)).toBe(2);
 }); 

1. Learn some key concepts @juanlizarazog @juanlizarazog Specs •Short of specification •Group of expectations (that test the state of the code). •spec -> test it('adds 1 + 1 to equal 2', () => {
 expect(sum(1, 1)).toBe(2);
 }); 

1. Learn some key concepts @juanlizarazog @juanlizarazog Suites •Group of tests •Help us organize our units describe('sum()', () => {
 // specs
 }); 

3. Do not test implementation details! Ever! I mean it. # @juanlizarazog 

@juanlizarazog test('adds 1 + 2 to equal 3', () => {
 expect(sum(1, 2)).toBe(3);
 }); function sum(a, b) {
 // return b + a;
 // return a + b;
 // return Number.parseInt(a, 10) + Number.parseInt(b, 10);
 // or anything else, we just care that the result is the sum
 } 

4. Write tests! @juanlizarazog 

Recap 1. Pick a library or framework 2. Learn some core concepts 3. Do not test implementation details 4. Write tests! @juanlizarazog 

UTAHJS2019 Enroll for free, use this code at checkout (10 available) @juanlizarazog 

Technology is our friend — @juanlizarazog 

Thank you!!! Udemy: https://www.udemy.com/course/unit-testing-your-javascript-with-jasmine/ Slides: https://speakerdeck.com/juanlizarazo @juanlizarazog