Dealing with legacy code - Valencia Codes Level Up #3

Presentation for the Valencia Codes meetup on June 1st, 2022.

https://www.meetup.com/valencia-codes/events/285716636/

Behaviour driven development, BDD, will help you work with any codebase.

BDD, TDD, linux, containers

Transcript

1. DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY DEALING WITH LEGACY CODE CODE CODE CODE CODE CODE CODE CODE CODE CODE CODE CODE José Miguel June 1, 2022
2. INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION INTRODUCTION who am I? staff software engineer @ zscaler passionate about OSS
4. MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION MOTIVATION
5. STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY STRATEGY reliability confidence joy tests automate
6. APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES APPROACHES top bottom bottom up
8. TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS TACTICS
9. TESTING FRAMEWORK TESTING FRAMEWORK junit testng scalatest jest pytest
10. BDD BDD test behaviours instead of implementations plain english
11. add(myArray, item) returns an array with bigger size Given a collection and an item When that item is added to that collection Then collection size increases
12. DO ONE THING WELL DO ONE THING WELL too many asserts -> testing too much?
13. TEST AS YOU MEAN IT TEST AS YOU MEAN IT
14. const suma = (a, b) => { return a + b; } it('suma(2,3) = suma(3, 2)', () => { expect(suma(2, 3)).toBe(suma(3, 2)); });
15. const suma = (a, b) => { return a + b; } describe('Addition', () => { describe('given two numbers', () => { it('must return the same result independently of their order', () => { expect(suma(2, 3)).toBe(suma(3, 2)); }); }); });
16. PASS ./suma.test.js ✓ suma(2,3) = suma(3, 2) (1 ms) PASS ./suma.test.js Addition given two numbers ✓ must return the same result independently of their order (2 ms)
17. TESTS ARE YOUR PLAYGROUND TESTS ARE YOUR PLAYGROUND REPL is your friend, with a bad memory
18. FUNCTIONAL PROGRAMMING FUNCTIONAL PROGRAMMING not crazy stuff, just: inmutability avoid side effects readibility
19. TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING TOOLING containers wiremock automate: make build make run
20. BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY BY THE WAY we’re hiring
21. FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP FOLLOW UP @jm2dev
22. Q & A Q & A Q & A Q & A Q & A Q & A Q & A Q & A Q & A Q & A Q & A Q & A