Leveraging Xcode Code Coverage

Learn how to exploit Xcode Code Coverage information using the latest tools from Apple and the community.

Transcript

1. Leveraging Xcode Code Coverage Simone Civetta Monday, 13th July - Minsk, Belarus
2. What is Code Coverage?
3. Testing
4. Metric that measures the value of your tests
5. Code Coverage detects ☞ Which code is executing when we're running the tests ☞ Which code is untested
6. How does it work? ☞ The information is gathered in two steps ☞ compile time ☞ runtime ☞ Tools count each expression that is executed
7. Code coverage on iOS
8. Code coverage on iOS until last month
10. Objective-C
11. Swift
12. Swift
14. How it worked ☞ LLVM creates annotation and data files: ☞ .gcno ☞ .gcda
15. How to enable in Xcode
18. How to enable via command line
19. GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES GCC_GENERATE_TEST_COVERAGE_FILES=YES xcodebuild [...] test
20. Tools
21. Tools ☞ Coverstory ☞ gcovr ☞ lcov ☞ Slather
22. Slather Exports to: - HTML - Gutter JSON - Cobertura XML github.com/venmo/Slather
23. But, also
24. Swiftcov swiftcov github.com/realm/SwiftCov ☞ Supports gcov format ☞ Uses breakpoints to gather coverage data
26. Code coverage on iOS
27. Code coverage on iOS since last month
29. Objective-C
30. Swift
31. A new format ☞ gcov ☞ profdata
32. Xcode generates profdata files for ☞ Swift ☞ ...and Objective-C
33. How to enable in Xcode
37. How to enable via command line
38. xcodebuild [...] test -enableCodeCoverage YES
39. xcodebuild -scheme MoDevByProject -destination "name=iPhone 6,OS=latest" -enableCodeCoverage YES test
40. Exploiting the data ☞ llvm-cov
41. Exploiting the data $XCODE_PATH/Toolchains/XcodeDefault.xctoolchain/usr/bin/llvm-cov show -instr-profile MY_PROJECT_PROFDATA MY_PROJECT_BINARY_FILE
43. Tools
44. Tools ☞ Slather ☞ Xcode Server
45. Slather github.com/venmo/slather/pull/92
46. Xcode Server
49. Summing up
50. Doesn't tell you if your code is bad ...
53. Doesn't tell you if your code is bad But can help writing better code
54. You're just minutes away from collecting Code Coverage info for Swift Start soon!
55. Thank you
56. Simone Civetta @viteinfinite Xebia IT Architects