Jacoco report target filtering.

[jtrobec]

Adds an argument for the jacoco jvm coverage processor that filters targets included in reports using a list of regular expressions.

Problem

The current implementation of jacoco code coverage will produce a report that includes all targets used in the test run. This includes targets not directly under test, but dependencies of the package actually under test. As a result, there's a lot of undesirable noise in the reports.

Solution

Introduce a parameter to filter the class files supplied to the jacoco cli when the report is produced. The jacoco cli does not provide a native parameter for exclusions, and instead the best we can do is to exclude class files when generating the reports. Classes that aren't passed to the cli during report generation aren't included in the resulting report.

The parameter I've added is a list of regular expressions. When specified, pants will only pass targets that match one of the regexes to the cli during report generation. Any target that doesn't match the pattern will be excluded, and thus not show up in the report.

[stuhood]

Thanks!

[stuhood]

Thanks, looks good! Will merge on green.

[stuhood]

You hit a flaky test. Going to merge. Thanks!

[ggetv]

Can someone give an example of using this new filter option, cannot find it in the documentation for junit test?

I am using pants 1.15.0, tried to set the option in this way: --test-junit-coverage-jacoco-target-filters="[com.foo.bar,com.foo.bar2]", but got this error: Exception message: Unrecognized command line flags on scope 'test.junit': --coverage-jacoco-target-filters

The full command:

./pants test.junit --cache-test-junit-ignore --test-junit-coverage-processor=jacoco --test-junit-coverage --test-junit-output-mode=ALL --no-test-junit-timeouts --test-junit-html-report --test-junit-open --test-junit-coverage-open --test-junit-coverage-jacoco-target-filters="[com.foo.bar,com.foo.bar2]" "src/test/java/foo::"

I checked release history, 1.15.0 is released on 4/15/2019, so this PR should be included already?

Can someone give some idea how to use this new filter option?

[baroquebobcat]

I think it's just --jacoco-target-filters, not --test-junit-coverage...

[ggetv]

@baroquebobcat yes, --jacoco-target-filters works! thanks so much!
@stuhood if this option is not included in the Pants document, can we please add it? thanks in advance.

[stuhood]

It should be, under jacoco on this page: https://www.pantsbuild.org/options_reference.html

[ggetv]

@stuhood found it under jacoco section, thanks a lot! I was looking at test.junit section advanced options, since cobertura exclusion was there. Thanks for the info and help!