Code Coverage for Swift Applications

Code coverage for the Swift language measures executed and non-executed code during testing, such as unit test cases. It identifies areas of software not exercised by a test case series. Code coverage metrics establish baselines for writing new test cases to boost coverage and determine quantitative metrics.

Code coverage for Swift applications example

Identify the project folder requiring instrumentation and generate coverage data, ensuring the project is configured and testable.

Enable the RKTracer tool

Run the rktracer -on command on the Swift folders you want to instrument.

rktracer -on foldername1 .swift -v
rktracer -on foldername2 .swift -v

Rebuild application

Clean and rebuild the application.

swift package clean

swift build

Run tests on the instrumented application

Run your tests against the instrumented application.

swift run

Generate code coverage reports

Run the rkresults command in the application root folder, where the rktracer folder was generated during instrumentation.

rktracer -off foldername .swift -v
rktracer -off foldername2 .swift -v

Enable coverage for selected files

You can scope coverage to specific folders, files, or functions by editing rktracer.config.

Generate coverage reports for the selected folders

ignore *.swift

instrument */power/* */core/* */keys/*

never */firmware_loader/* */lockdown/*

Generate coverage reports only for selected functions from three different files

ignore *.swift

instrument *source-file-X.swift *source-file-Y.swift *source-file-Z.swift

function-ignore *

function-instrument fun_X() fun_Y() fun_Z()

Next steps

Once your Swift application reports coverage, the same RKTracer workflow applies across other build systems and languages. Browse the rest of the documentation, or read more about how RKTracer measures coverage through MC/DC.