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

Feature Parity in 25% of the Dev Hours @TheQuinnGil QuinnGil.com

@TheQuinnGil QuinnGil.com Technical Practices for Sustainable Code

Quinn Gil Software Development Coach International Speaker on Software Development Past 15 years focused on High Quality code Blog at QuinnGil.com @TheQuinnGil QuinnGil.com

This is for you. @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices @TheQuinnGil QuinnGil.com

Tests @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection

Sustainable Code through Technical Practices ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection No Getters / No Setters @TheQuinnGil QuinnGil.com

Technical Practices - No Getters - Defined 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 @TheQuinnGil QuinnGil.com

Technical Practices - No Getters No Getters? No Way! @TheQuinnGil QuinnGil.com

No Getters Technical Practices @TheQuinnGil QuinnGil.com

Technical Practices - No Getters Why No Getters? @TheQuinnGil QuinnGil.com

Technical Practices - No Getters How? @TheQuinnGil QuinnGil.com

Technical Practices - No Getters - How? The Class Does It @TheQuinnGil QuinnGil.com

Technical Practices - No Getters 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(); } } } @TheQuinnGil QuinnGil.com

Technical Practices - No Getters / No Setters public class FizzBuzz{ 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 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(); } } } @TheQuinnGil QuinnGil.com

Technical Practices - No Getters / No Setters Benefits @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices No Getters / No Setters @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection Sustainable Code from Encapsulating Behavior

Sustainable Code through Technical Practices `if` Only As Guard Clause @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection

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

Technical Practices - `if` Only As Guard Clause Default Path @TheQuinnGil QuinnGil.com

`if` Only As Guard Clause - Default Path public class FizzBuzz{ 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; } } @TheQuinnGil QuinnGil.com

public class FizzBuzz{ 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; } } `if` Only As Guard Clause - Default Path public class FizzBuzz{ private int _input; public FizzBuzz(int input) => _input = input; public string Result(){ if (_input % 15 == 0) return "FizzBuzz"; if (_input % 3 == 0) return "Fizz"; if (_input % 5 == 0) return "Buzz"; return _input.ToString(); } } @TheQuinnGil QuinnGil.com

Technical Practices - `if` Only As Guard Clause Cascading Changes @TheQuinnGil QuinnGil.com

Technical Practices - `if` Only As Guard Clause Cascading Changes switch and else - always evil @TheQuinnGil QuinnGil.com

Technical Practices - `if` Only As Guard Clause How? @TheQuinnGil QuinnGil.com

`if` Only As Guard Clause - Default Path public class FizzBuzz{ private int _input; public FizzBuzz(int input) => _input = input; public string Result(){ if (_input % 15 == 0) return "FizzBuzz"; if (_input % 3 == 0) return "Fizz"; if (_input % 5 == 0) return "Buzz"; return _input.ToString(); } } public class FizzBuzz{ 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; } } @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices `if` Only As Guard Clause @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection Sustainable Code from Limited Branching; Smaller Methods; Encapsulated Behavior Decisions

Sustainable Code through Technical Practices Isolate Their Code @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { HttpClient httpClient = new HttpClient(); HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { //COUPLING HttpClient httpClient = new HttpClient(); HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { //COUPLING HttpClient httpClient = new HttpClient(); //EXCEPTION HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { //COUPLING HttpClient httpClient = new HttpClient(); //EXCEPTION HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); //EXCEPTION, COUPLING JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { //COUPLING HttpClient httpClient = new HttpClient(); //EXCEPTION HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); //EXCEPTION, COUPLING JObject jsonContent = JObject.Parse(readAsStringAsync); //IMPERATIVE string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { //COUPLING HttpClient httpClient = new HttpClient(); //EXCEPTION HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); //EXCEPTION, COUPLING JObject jsonContent = JObject.Parse(readAsStringAsync); //IMPERATIVE string value = jsonContent.Value("some_key"); //EXCEPTION return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { HttpClient httpClient = new HttpClient(); HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpClientBookEnd httpClient = new HttpClientFacade(); HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpClientBookEnd httpClient = new HttpClientFacade(); IHttpResponseMessageBookEnd httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpClientBookEnd httpClient = new HttpClientFacade(); IHttpResponseMessageBookEnd httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.ContentAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpResponseMessageBookEnd httpResponseMessage = await _httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.ContentAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpResponseMessageBookEnd httpResponseMessage = await _httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.ContentAsStringAsync(); IParsedObject parsedObject = _parser.Parse(readAsStringAsync); string value = parsedObject.StringValue("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { IHttpResponseMessageBookEnd httpResponseMessage = await _httpClient.SendAsync(r); IParsedObject parsedObject = await httpResponseMessage.ParsedContent(_parser); string value = parsedObject.StringValue("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - 3rd Party public async Task NetworkCall(HttpRequestMessage r) { HttpClient httpClient = new HttpClient(); HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(r); string readAsStringAsync = await httpResponseMessage.Content.ReadAsStringAsync(); JObject jsonContent = JObject.Parse(readAsStringAsync); string value = jsonContent.Value("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } public async Task NetworkCall(HttpRequestMessage r) { IHttpResponseMessageBookEnd httpResponseMessage = await _httpClient.SendAsync(r); IParsedObject parsedObject = await httpResponseMessage.ParsedContent(_parser); string value = parsedObject.StringValue("some_key"); return value.Contains("expected_Value") ? "Success" : "Failure"; } @TheQuinnGil QuinnGil.com

What Else? Technical Practices - Isolate Their Code @TheQuinnGil QuinnGil.com

Operating System Technical Practices - Isolate Their Code @TheQuinnGil QuinnGil.com

How? Technical Practices - Isolate Their Code @TheQuinnGil QuinnGil.com

Technical Practices - Isolate Their Code - How? HttpClient httpClient = new HttpClient(); @TheQuinnGil QuinnGil.com IHttpClientBookEnd httpClient = new HttpClientFacade();

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

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

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

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

User Interface Technical Practices - Isolate Their Code @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices Isolate Their Code @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection Sustainable Code from Full Testability; Narrow Scope of Change; Reduced Complexity

Sustainable Code through Technical Practices @TheQuinnGil QuinnGil.com ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection

Feature Parity in 25% of the Dev Hours @TheQuinnGil QuinnGil.com

THANK YOU! @TheQuinnGil QuinnGil.com

Sustainable Code through Technical Practices ● No Getters / No Setters ● `if` Only As Guard Clause ● Isolate Their Code ● Never `null` ● No `new` inline ● Composition, Not Inheritance ● ● Be Immutable ● No Primitives ● Extract Cohesion ● No Public Statics ● Never Reflection @TheQuinnGil QuinnGil.com