Technical Practices for Sustainable Code - Chicago Code Camp 2019

@TheQuinnGil https://QuinnGil.com
with
Technical Practices for
Sustainable Code
Feature Parity in
25% of the Dev Hours

View Slide

Technical Practices for
Sustainable Code

View Slide

Quinn Gil
Blog -- QuinnGil.com
Twitter -- TheQuinnGil
Github -- Fyzxs

View Slide

This is for you.

View Slide

Sustainable Code

View Slide

Why?
Sustainable Code

View Slide

What’s Our Job?
Sustainable Code - Why?

View Slide

Sustainably grow the value of
the company’s digital assets.
Sustainable Code - What’s our job?

View Slide

I’m Lazy
Sustainable Code

View Slide

How?
Sustainable Code

View Slide

Mindset Change
Sustainable Code - How?

View Slide

Technical Practices
Sustainable Code - How?

View Slide

Sustainable Code
through
Technical Practices

View Slide

Sustainable Code through Technical Practices
● No Getters / No Setters
● `if` Only As Guard Clause
● Isolate Their Code
● Never `null`
● Limit Object Creation
● Composition, Not Inheritance
●
● Be Immutable
● No Primitives
● Extract Cohesion
● No Public Statics
● Never Reflection

View Slide

But First!

View Slide

Fully Test Behaviors
Sustainable Code - Testing!

View Slide

● Never `null`
●
● Be Immutable
● No Primitives

View Slide

No Getters / No Setters
Technical Practices

View Slide

Technical Practices - No Getters / No Setters
class FizzBuzzBag{
public int Input{ get; set; }
public string Result{ get; set; }
}
class FizzBuzzBag:
def __init__(self):
self._result = None
self._input = None
@property
def result(self):
return self._result
@result.setter
def result(self, value):
self._result = value
@property
def input(self):
return self._input
@input.setter
def input(self, value):
self._input = value
class FizzBuzzBag{
private int input;
private String result;
public String getResult(){
return result;
}
public void setResult(String value){
result = value;
}
public int getInput(){
return input;
}
public void setInput(int value){
input = value;
}
}
class FizzBuzzBag
attr_accessor :input
attr_accessor :result
end

View Slide

No Way

View Slide

Technical Practices

View Slide

Technical Practices - No Getters
Why?

View Slide

Technical Practices - No Setters
Why?

View Slide

How?

View Slide

No Getters / No Setters - How?
The Class Does It

View Slide

public class FizzBuzz{
public int Input { get; set; }
public string Result { get; set; }
}
public static class FizzBuzzUtils{
public static void Calculate(FizzBuzz fb){
if (fb.Input % 3 == 0){
fb.Result = "Fizz";
}
if (fb.Input % 5 == 0){
if (fb.Result == null){
fb.Result = "Buzz";
} else {
fb.Result += "Buzz";
}
}
if (string.IsNullOrEmpty(fb.Result)){
fb.Result = fb.Input.ToString();
}
}
}

View Slide

private readonly int _input;
public FizzBuzz(int input) => _input = input;
public string Result(){
string result = null;
if (_input % 3 == 0) result = "Fizz";
if (_input % 5 == 0){
if (result == null) result = "Buzz";
else result += "Buzz";
}
if (string.IsNullOrEmpty(result)){
result = _input.ToString();
}
return result;
}
}
public int Input { get; set; }
public string Result { get; set; }
}
public static class FizzBuzzUtils{
public static void Calculate(FizzBuzz fb){
if (fb.Input % 3 == 0){
fb.Result = "Fizz";
}
if (fb.Input % 5 == 0){
if (fb.Result == null){
fb.Result = "Buzz";
} else {
fb.Result += "Buzz";
}
}
if (string.IsNullOrEmpty(fb.Result)){
fb.Result = fb.Input.ToString();
}
}
}

View Slide

Technical Practices - No Setters
Benefits

View Slide

Technical Practices

View Slide

● Never `null`
●
● Be Immutable
● No Primitives

View Slide

`if` Only As Guard Clause
Technical Practices

View Slide

Technical Practices - `if` Only As Guard Clause
No Way

View Slide

Success Path

View Slide

`if` Only As Guard Clause - Success Path
if (_input % 5 == 0){
}
}
return result;
}
}

View Slide

`if` Only As Guard Clause - Success Path
if (_input % 15 == 0) return "FizzBuzz";
if (_input % 3 == 0) return "Fizz";
if (_input % 5 == 0) return "Buzz";
return _input.ToString();
}
}
if (_input % 5 == 0){
}
}
return result;
}
}

View Slide

Cascading Changes

View Slide

How?

View Slide

}
}

View Slide

}
}
if (IsFizzBuzz()) return "FizzBuzz";
if (IsFizz()) return "Fizz";
if (IsBuzz()) return "Buzz";
return InputToString();
}
}

View Slide

`if` Only As Guard Clause
Technical Practices

View Slide

● Never `null`
●
● Be Immutable
● No Primitives

View Slide

Isolate Their Code
Technical Practices

View Slide

Technical Practices - Isolate Their Code - 3rd Party
private readonly string _input;
public FizzBuzz(string input) => _input = input;
JObject jObject = JObject.Parse(_input);
int input = jObject.Value("number");
if (IsFizzBuzz(input)) return "FizzBuzz";
if (IsFizz(input)) return "Fizz";
if (IsBuzz(input)) return "Buzz";
return input.ToString();
}
}

View Slide

Technical Practices - Isolate Their Code - 3rd Party
private readonly string _input;
private readonly IParser _parser;
public FizzBuzz(string input) => _input = input;
IParsedObject pObject = _parser.Parse(_input);
int input = pObject.IntValue("input");
if (IsFizzBuzz(input)) return "FizzBuzz";
if (IsFizz(input)) return "Fizz";
if (IsBuzz(input)) return "Buzz";
return input.ToString();
}
}

View Slide

Isolate Their Code
Technical Practices

View Slide

Operating System
Technical Practices - Isolate Their Code

View Slide

How?

View Slide

Technical Practices - Isolate Their Code - How?
internal class HttpClientBookEnd : IHttpClientBookEnd{
private static HttpClient _testClient;
#if DEBUG
public static void SetTestClient(HttpClient testClient) => _testClient = testClient;
#endif
private readonly HttpClient _httpClient;
public HttpClientBookEnd() : this(new HttpClient()){}
private HttpClientBookEnd(HttpClient httpClient) => _httpClient = httpClient;
public void SendRequestAsync(HttpRequestMessage msg) => HttpClient().SendAsync(msg);
private HttpClient HttpClient() => _testClient ?? _httpClient;
}

View Slide

User Interface

View Slide

Isolate Their Code
Technical Practices

View Slide

● Never `null`
●
● Be Immutable
● No Primitives

View Slide

Never `null`
Technical Practices

View Slide

Why?
Technical Practices - Never `null`

View Slide

How?

View Slide

public string CalculateThing(ICanBeNull canBeNull)
{
if (canBeNull == null) return "Default";
IAlsoNull alsoNull = canBeNull.Example();
if (alsoNull == null) return "Default";
string sample = alsoNull.Sample();
if (sample == null) return "Default";
return sample;
}

View Slide

public string CalculateThing(ICanNotBeNull canNotBeNull)
{
return canNotBeNull.Example().Sample();
}
{
return sample;
}

View Slide

{
return sample;
}
{
}
public void Foo(){
string thing = _bar.CalculateThing(_canBeNull);
//Do something with `thing`
}

View Slide

{
return sample;
}
{
}
public void Foo(){
string thing = _bar.CalculateThing(_canBeNull);
}
public void Foo(){
string thing = _canNotBeNull.Example().Sample();
}

View Slide

{
return sample;
}
{
}
public class NullObject : ICanNotBeNull{
public IAlsoNotNull Example() => new NullObjectAlso();
}
public class NullObjectAlso : IAlsoNotNull{
public string Sample() => "Default";
}

View Slide

Languages and Null

View Slide

Never `null`
Technical Practices

View Slide

● Never `null`
●
● Be Immutable
● No Primitives

View Slide

THANK YOU!

View Slide

Technical Practices for Sustainable Code - Chicago Code Camp 2019

Technical Practices for Sustainable Code - Chicago Code Camp 2019

Quinn

More Decks by Quinn

Other Decks in Programming

Featured

Transcript