Android code coverage instructions

These are instructions for collecting code coverage data for android instrumentation and JUnit tests. For Clang(C++) code coverage refer to [clang coverage].

[TOC]

How JaCoCo coverage works

In order to use JaCoCo code coverage, we need to create build time pre-instrumented class files and runtime .exec files. Then we need to process them using the build/android/generate_jacoco_report.py script.

How to collect coverage data

1. Presentation on class verification in Chrome and WebView (Google-only

`gn target_os = "android" usejacococoverage = true `

Now when building, pre-instrumented files will be created in the build directory.

1. Presentation on class verification in Chrome and WebView (Google-only

the .exec file. For example, you can run chrome JUnit tests: out/Debug/bin/run_chrome_junit_tests --coverage-dir /tmp/coverage.

1. Presentation on class verification in Chrome and WebView (Google-only

automatically if they are in the same directory.

How to generate coverage report

1. Presentation on class verification in Chrome and WebView (Google-only

report using generate_jacoco_report.py, for example:

`shell build/android/generatejacocoreport.py \ --format html \ --output-dir /tmp/coverage_report/ \ --coverage-dir /tmp/coverage/ \ --sources-json-dir out/Debug/ \ ` Then an index.html containing coverage info will be created in output directory:

` [INFO] Loading execution data file /tmp/coverage/testTitle.exec. [INFO] Loading execution data file /tmp/coverage/testSelected.exec. [INFO] Loading execution data file /tmp/coverage/testClickToSelect.exec. [INFO] Loading execution data file /tmp/coverage/testClickToClose.exec. [INFO] Loading execution data file /tmp/coverage/testThumbnail.exec. [INFO] Analyzing 58 classes. `

1. Presentation on class verification in Chrome and WebView (Google-only

only one file will be generated as XML or CSV report. `shell build/android/generatejacocoreport.py \ --format xml \ --output-file /tmp/coverage_report/report.xml \ --coverage-dir /tmp/coverage/ \ --sources-json-dir out/Debug/ \ `

or

`shell build/android/generatejacocoreport.py \ --format csv \ --output-file /tmp/coverage_report/report.csv \ --coverage-dir /tmp/coverage/ \ --sources-json-dir out/Debug/ \ `

1. Presentation on class verification in Chrome and WebView (Google-only

when generating coverage for downstream targets, use the --include-substr-filter option to choose jars in the desired directory. Eg. for generating coverage report for Clank internal repo `shell build/android/generatejacocoreport.py --format html \ --output-dir /tmp/coverage_report/ --coverage-dir /tmp/coverage/ \ --sources-json-dir out/java_coverage/ \ --include-substr-filter obj/clank `

[clang coverage]: https://chromium.googlesource.com/chromium/src/+/HEAD/docs/testing/code_coverage.md