Code Review

Code Review Tools, Configurations, and Recommendations

Linters

Swift Linters

• SwiftLint
  • https://github.com/realm/SwiftLint
  • Configuration: .swiftlint.yml
    • Setup options:
      • ln -s swiftlint.yml .swiftlint.yml
      • mv swiftlint.yml .swiftlint.yml

swiftlint --config .swiftlint.yml

Objective-C Linters

• oclint
  • https://github.com/oclint/oclint
  • Configuration: .oclint
    • Setup options:
      • ln -s oclint.yml .oclint
      • mv oclint.yml .oclint

xcodebuild -project MyProject.xcodeproj -scheme MyScheme -sdk macosx -configuration Debug build | xcpretty -r json-compilation-database -o compile_commands.json
oclint-json-compilation-database
oclint -rc CYCLOMATIC_COMPLEXITY=10 -rc LONG_CLASS=1000

OCLint requires a "JSON compilation database" files to perform it's linting. This file contains a list of the Xcode build plan with the compiler flags that Xcode will pass to the compiler for each file. This complicates using oclint since we have to first run a build pass on the project, post-process the output using xcpretty, then post-process the xcpretty output using the oclint-json-compilation-database tool.

• https://github.com/xcpretty/xcpretty

gem install xcpretty

Formatters

Swift Formatters

• swift-format
  • https://github.com/apple/swift-format
  • Methodology
    • Parses code into AST then outputs AST through pretty printing
    • Strips all custom formatting
    • Can modify output formatting via configuration
  • Configuration: .swift-format.json
    • Setup options:
      • ln -s swift-format.json .swift-format.json
      • mv swift-format.json .swift-format.json

swiftformat **/*.swift

• SwiftFormat
  • https://github.com/nicklockwood/SwiftFormat
  • Methodology
    • Text parser
    • Operates on line groups
    • Can ignore some text via configuration
  • Configuration: .swiftformat
    • Rules
    • Setup options:
      • ln -s swiftformat.cfg .swiftformat
      • mv swiftformat.cfg .swiftformat

swiftformat **/*.swift

Objective-C Formatters

• clang-format
  • https://clang.llvm.org/docs/ClangFormatStyleOptions.html
  • Standard with Xcode
  • Configuration: .clang-format
    • Setup options:
      • ln -s clang-format.yml .clang-format
      • mv clang-format.yml .clang-format

xcrun clang-format -i **/*.[hm]

Style Guides

• Apple sample code:
  • Apple Swift Style Sample
• Style guides based on Apple documentation and sample code
  • Google Swift Style Guide