Be the Quality You Want to See in Your App [Swift Edition]

This talk has been given on Thursday, June 16th at AltConf 2016.

Once upon a time, back in the dark ages of Objective-C, monitoring the quality metrics of a codebase was a cumbersome operation, which involved the setup of obscure tools and easily produced unreliable results.

Times have changed and, just a few months after the announcement of Swift, it is now straightforward for iOS and macOS developers to improve their toolbelts and analyse the evolution of their code throughout the weeks.

During this talk you will discover why and how to monitor your codebase’s health, by leveraging metrics such as code complexity, duplication, coverage and others, by adopting open-source tools such as Fastlane, Lizard, SwiftLint, Slather, and the Swift SonarQube plugin.

Transcript

2. Welcome!
4. September, 2014
5. Code Quality Metrics...
6. Code Quality Metrics... ...in Objective-C
7. Technical Debt
8. Tooling in 2014
9. Tooling in 2014 ☞ gcov ☞ PMD ☞ bash scripts ☞ ...
10. Back to Swift
11. AltConf 2015
13. I Code metrics
14. # lines of code
15. ❝Mo Code Mo Problems❞
16. # of tests
17. Code coverage
18. Cyclomatic complexity func example(a: Int, b: Int, c:Int, d:Int) { // 1 if a == b { // 2 print("I") } else if (c == d) { // 3 for index in 1...5 { // 4 print("Have") } } else { // 5 switch c { case 1: // 6 print("No") case 2: // 7 print("Idea") default: // 8 print("What I'm doing") } } }
19. NPath complexity func example(a:Int, b:Int) { if a > 10 { print(1) } else { print(2) } if a > b { print(3) } else { print(4) } } // Result: 4
20. Duplications
21. Depth of inheritance
22. Class coupling
23. Code issues
24. NCSS
26. SPLINTER
27. S wift P layground L aunch INTER val
28. II How to measure
29. swiftc
30. SwiftLint github.com/realm/SwiftLint
31. SwiftLint ☞ Static analysis ☞ via AST... ☞ ...and Regular Expressions ☞ Supports custom rules ☞ Detects cyclomatic complexity
32. SwiftLint ☞ $ brew install swiftlint ☞ $ swiftlint Rules ☞ $ swiftlint rules <rule_name>
33. Tailor github.com/sleekbyte/tailor
34. Tailor ☞ Cross-platform ☞ Different output formats ☞ Based on ANTLR ☞ Simpler rules
35. Tailor $ brew install tailor $ tailor
36. Lizard github.com/terryyin/lizard Cyclomatic complexity analyzer pip install lizard
37. Slather github.com/SlatherOrg/slather
38. Slather ☞ Reads Xcode Code Coverage information ☞ Outputs to a number of different formats (included Cobertura) ☞ Supports a plethora of systems, such as Coveralls, Codecov, etc
39. Slather $ gem install slather $ slather coverage [FORMAT] -b [BUILD_DIR] --scheme [SCHEME] [PROJECT]
40. To sum up ☞ swiftc ☞ SwiftLint ☞ Tailor ☞ Lizard ☞ Slather
42. III Integration
44. Codecov codecov.io
45. Codecov ☞ GitHub Integration ☞ Code coverage
46. Hound github.com/houndci/hound
47. Hound ☞ Code issues (via SwiftLint) ☞ GitHub Integration
50. Code climate codeclimate.com
51. Code climate ☞ Code issues (via Tailor) ☞ GitHub Integration ☞ Code Coverage
52. Xcode Bots
53. Xcode Bots ☞ Code issues (via swiftc and SwiftLint) ☞ Code Coverage
57. SonarQube sonarqube.org
58. SonarQube ☞ Acts as an hub for a variety of code metrics ☞ Code Coverage ☞ Code Issues ☞ SCM ☞ Complexity (Project-wide) ☞ Duplications
59. SonarQube - Installing $ brew install sonar Tip ☞ Configure a database (MySQL or Postgre)
60. SonarQube Runner
61. SonarQube Runner The frontend for executing sonar Reads a sonar-project.properties file in the project folder
62. SonarQube Runner - Installing $ brew install sonar-runner # Front end
63. SonarQube + Swift == !
64. SonarQube + Swift ==
65. SonarQube Swift plugin github.com/Backelite/sonar-swift
66. SonarQube Swift plugin Retrieves reports from: ☞ Test execution ☞ SwiftLint ☞ Lizard ☞ Slather
67. SonarQube Swift plugin Adds: ☞ Documentation count ☞ LOCs ☞ CPD (Duplication)
68. SonarQube Swift plugin - Installing a. Build from sources: $ cd path/to/swift/plugin $ ./build-and-deploy.sh b. Or download pre-built jar file into $SONARQUBE_HOME/extensions/plugins
74. III bis Automation
76. Fastlane
77. Fastlane actions we use ➀ scan ➁ slather ➂ swiftlint ➃ lizard (via sh) ➄ sonar
78. 0. Fastlane platform :ios do desc "Collect all the metrics" lane :metrics do
79. 1. scan scan(scheme: "MyProject", code_coverage: true, xcargs: "-derivedDataPath ./DerivedData", output_directory: "./reports")
80. 2. Slather slather(cobertura_xml: true, scheme: "MyProject", output_directory: "./reports", build_directory: "./DerivedData", binary_basename: "MyProject", proj: "./MyProject.xcodeproj")
81. 3. SwiftLint swiftlint(output_file: "./reports/swiftlint.txt", ignore_exit_status: true)
82. 4. Lizard sh("cd .. && lizard ./MyProject -l swift --xml > ./reports/lizard-report.xml")
83. 5.1 Sonar: sonar-project.properties sonar.projectKey = MyProject sonar.projectName = MyProject sonar.language = swift sonar.sources = MyProject # Sources Folder sonar.tests = MyProjectTests # Test Sources Folder # Report paths sonar.junit.reportsPath = reports/ sonar.swift.lizard.report = reports/lizard-report.xml sonar.swift.coverage.reportPattern = reports/cobertura.xml sonar.swift.SwiftLint.report = reports/*SwiftLint.txt
84. 5.2 Sonar-Runner - Fastlane sonar(project_version: Time.new.strftime("%Y.%m.%d.%H.%M"))
85. Complete example platform :ios do desc "Collect all the metrics" lane :metrics do scan(scheme: "MyProject", code_coverage: true, xcargs: "-derivedDataPath ./DerivedData", output_directory: "./reports") slather(cobertura_xml: true, jenkins: true, scheme: "MyProject", output_directory: "./reports", build_directory: "./DerivedData", binary_basename: "MyProject", proj: "./MyProject.xcodeproj") sh("cd .. && lizard ./MyProject -l swift --xml > ./reports/lizard-report.xml") swiftlint(output_file: "./reports/swiftlint.txt", ignore_exit_status: true) sonar(project_version: Time.new.strftime("%Y.%m.%d.%H.%M")) end end
86. IV The bottom line
87. Do not blindly believe in metrics
88. Why should we use them? ☞ understand which components need reworking ☞ identify potential risks ☞ track progress ☞ have an overall view of large systems
89. Automate
90. Pick complementary metrics
91. Aim for all metrics (rather than excelling in a single one)
92. Be honest with yourself
93. Share the results with your team
94. Analyse your metrics
95. Be the quality you want to see in your app
96. Thank you!
97. @viteinfinite
98. One more film
103. CFP is open papercall.io/frenchkit-2016
104. Thank you! @viteinfinite
105. THE USE OF ANY COPYRIGHTED MATERIAL IS USED UNDER THE GUIDELINES OF "FAIR USE" IN TITLE 17 § 107 OF THE UNITED STATES CODE. SUCH MATERIAL REMAINS THE COPYRIGHT OF THE ORIGINAL HOLDER AND IS USED HERE FOR THE PURPOSES OF EDUCATION, COMPARISON, AND CRITICISM ONLY. NO INFRINGEMENT OF COPYRIGHT IS INTENDED.