An exciting intro to JavaScript unit testing

Utah JS 2019

Transcript

1. An exciting intro to Javascript unit testing Juan Lizarazo @juanlizarazog 2019 UtahJS Conference
2. Hi I am Juan Lizarazo @juanlizarazog
3. No, this talk is not about AMP :) Still, check it out at https://amp.dev
5. An exciting intro to Javascript unit testing @juanlizarazog
6. 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
7. How to make unit testing exciting? @juanlizarazog
8. Let’s face it:
 
 Unit testing is boring! @juanlizarazog
9. But learning about it doesn’t have to be! @juanlizarazog
10. •Testing individual units of code • Unit is the smallest testable part What is unit testing? @juanlizarazog
11. •Trust changes you make on existing (already tested) code. •Code quality •Changes occur quickly •Documents your own code •Automation Why? @juanlizarazog
12. How do we unit test JavaScript? @juanlizarazog
13. 1. Pick a library or framework @juanlizarazog
14. 2. Learn some core concepts @juanlizarazog
15. 1. Learn some key concepts @juanlizarazog @juanlizarazog Expectations •Test the state of the code expect(1 + 1).toBe(2);
16. 1. Learn some key concepts @juanlizarazog @juanlizarazog Matchers •It’s just a function •Implements a boolean comparison expect(1 + 1).toBe(2);
17. 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);
 });
18. 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);
 });
19. 1. Learn some key concepts @juanlizarazog @juanlizarazog Suites •Group of tests •Help us organize our units describe('sum()', () => {
 // specs
 });
20. 3. Do not test implementation details! Ever! I mean it. # @juanlizarazog
21. @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
 }
22. 4. Write tests! @juanlizarazog
23. Recap 1. Pick a library or framework 2. Learn some core concepts 3. Do not test implementation details 4. Write tests! @juanlizarazog
24. UTAHJS2019 Enroll for free, use this code at checkout (10 available) @juanlizarazog
25. Technology is our friend — @juanlizarazog
26. Thank you!!! Udemy: https://www.udemy.com/course/unit-testing-your-javascript-with-jasmine/ Slides: https://speakerdeck.com/juanlizarazo @juanlizarazog