Document how to measure the test coverage
Since the source and test packages differ in the code-owners plugin, we
need to override the instrumentation filter from Bazel (otherwise the
packages for which no test package exists will be missing in the
report).
Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Iebe401f1de1891d97b726e97c5ffddd92a20ccd2
diff --git a/resources/Documentation/build.md b/resources/Documentation/build.md
index 6c2db04..38d44ed 100644
--- a/resources/Documentation/build.md
+++ b/resources/Documentation/build.md
@@ -22,6 +22,14 @@
```
bazel test //plugins/@PLUGIN@/...
```
+\
+To measure the test coverage run:
+
+```
+ bazel coverage --test_output=all plugins/code-owners/... --coverage_report_generator=@bazel_tools//tools/test:coverage_report_generator --combined_report=lcov --instrumentation_filter="^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/acceptance[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/acceptance/testsuite[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/api[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/api/impl[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/backend[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/common[/:],,^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/metrics[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/restapi[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/testing[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/util[/:],^//plugins/code-owners/java/com/google/gerrit/plugins/codeowners/validation[/:]" && genhtml -o . --ignore-errors source bazel-out/_coverage/_coverage_report.dat
+```
+\
+and then open the generated `index.html` in a browser.
---
