software quality - a whirlwind tour “is my code good?”

things to touch on

code reviews - to improve your code quality and level up as developers refactoring/code smells - to learn the mechanics of improving code

Themes: trade-offs deliberate context

What is quality? What makes code good? How do I know if my code is good?

LOC? Performant? Reliable? Easy to change? Easy to understand? Confidence? Profitable? Helpful?

Test Driven Development Behavior Driven Development Design patterns Single Responsibility Principle Don’t Repeat Yourself Rule of Threes Law of Demeter Metrics Refactoring Code Reviews Pair Programming Automated Testing Static Analyis Linters Style Guides SOLID YAGNI KISS Command-Query Separation Inversion of Control Cohesion Coupling Continuous Integration Continuous Deployment


who is doing it? what is it/what is it not? within a TDD workflow show the smallest types of refactoring before code smells (naming, express intent with methods) common patterns (extract method, class, rename)

show code side-by-side to evaluate refactoring show one example (maybe some polymorphism?) that doesnt exactly work recommendation: Fowler’s Refactoring trade-offs: you never know less about your program than you do right now

code smells

what is it? trade-offs: not always a problem explain how smells might conflict with each other common examples (feature envy, long method, shotgun surgery)

Message/Method Chains Hide delegate

// Uber.js

var matt = new Driver(“Matt”); matt.addRide(new Ride(“Carmel”, “Mass Ave”, new Time(“10am”))) matt.addRide(new Ride(“Mass Ave”, “Broad Ripple”, new Time(“9pm”)))

var total = 0.0; for each (Ride ride : matt.getRides()) { total = total + matt.calculate(ride) }

print “You earned: $” + total print “But we don’t provide benefits :(“

class Driver { String name Car car List rides

int calculate(ride) {
  var d = GeoUtils.calculate(ride.startLatitude, ride.startLongitude, 
    ride.endLatitude, ride.endLongitude);

  var s = 0;
  var t = getType()
  switch t {
    case "Black Car":
      s = 10.0
    case "Uber XL":
      s = 7.0
    case "Uber X":
      s = 5.0

  s = s + d * 0.50

  // Surge pricing after 6pm and Fri/Sat/Sun
  if (currentRide.requestedTime.hour >= 17 || >= 5) {
    s = s * 2.5

  return s * 1.05 //tax;

string getType() {
    if (car.getColor() == "black" && car.getYear() > 2010) {
        return "Black Car"
    } else if (car.getPassengerCount() > 4) {
        return "Uber XL"
    } else {
        return "Uber X"
} } ```

use Uber as context for examples

code reviews

who is doing them? giving context to reviewer code is read 10x more than written [cite] example of empty, “what” and “why” pull requests receiving feedback why junior devs should review code trade-offs: readability vs performance team vs individual learning/launching recommendation: exercism