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stage | group | info | type |
---|---|---|---|
Verify | Testing | To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments | reference, howto |
Test Coverage Visualization
- Introduced in GitLab 12.9.
- Feature flag removed in GitLab 13.5.
With the help of GitLab CI/CD, you can collect the test coverage information of your favorite testing or coverage-analysis tool, and visualize this information inside the file diff view of your merge requests (MRs). This will allow you to see which lines are covered by tests, and which lines still require coverage, before the MR is merged.
How test coverage visualization works
Collecting the coverage information is done via GitLab CI/CD's artifacts reports feature. You can specify one or more coverage reports to collect, including wildcard paths. GitLab will then take the coverage information in all the files and combine it together.
For the coverage analysis to work, you have to provide a properly formatted
Cobertura XML report to
artifacts:reports:cobertura
.
This format was originally developed for Java, but most coverage analysis frameworks
for other languages have plugins to add support for it, like:
- simplecov-cobertura (Ruby)
- gocover-cobertura (Golang)
Other coverage analysis frameworks support the format out of the box, for example:
- Istanbul (JavaScript)
- Coverage.py (Python)
Once configured, if you create a merge request that triggers a pipeline which collects coverage reports, the coverage will be shown in the diff view. This includes reports from any job in any stage in the pipeline. The coverage will be displayed for each line:
covered
(green): lines which have been checked at least once by testsno test coverage
(orange): lines which are loaded but never executed- no coverage information: lines which are non-instrumented or not loaded
Hovering over the coverage bar will provide further information, such as the number of times the line was checked by tests.
NOTE:
The Cobertura XML parser currently does not support the sources
element and ignores it. It is assumed that
the filename
of a class
element contains the full path relative to the project root.
Example test coverage configurations
JavaScript example
The following gitlab-ci.yml
example uses Mocha
JavaScript testing and nyc coverage-tooling to
generate the coverage artifact:
test:
script:
- npm install
- npx nyc --reporter cobertura mocha
artifacts:
reports:
cobertura: coverage/cobertura-coverage.xml
Java and Kotlin examples
Maven example
The following gitlab-ci.yml
example for Java or Kotlin uses Maven
to build the project and JaCoCo coverage-tooling to
generate the coverage artifact.
You can check the Docker image configuration and scripts if you want to build your own image.
GitLab expects the artifact in the Cobertura format, so you have to execute a few
scripts before uploading it. The test-jdk11
job tests the code and generates an
XML artifact. The coverage-jdk-11
job converts the artifact into a Cobertura report:
test-jdk11:
stage: test
image: maven:3.6.3-jdk-11
script:
- 'mvn $MAVEN_CLI_OPTS clean org.jacoco:jacoco-maven-plugin:prepare-agent test jacoco:report'
artifacts:
paths:
- target/site/jacoco/jacoco.xml
coverage-jdk11:
# Must be in a stage later than test-jdk11's stage.
# The `visualize` stage does not exist by default.
# Please define it first, or chose an existing stage like `deploy`.
stage: visualize
image: haynes/jacoco2cobertura:1.0.4
script:
# convert report from jacoco to cobertura
- 'python /opt/cover2cover.py target/site/jacoco/jacoco.xml src/main/java > target/site/cobertura.xml'
# read the <source></source> tag and prepend the path to every filename attribute
- 'python /opt/source2filename.py target/site/cobertura.xml'
needs: ["test-jdk11"]
dependencies:
- test-jdk11
artifacts:
reports:
cobertura: target/site/cobertura.xml
Gradle example
The following gitlab-ci.yml
example for Java or Kotlin uses Gradle
to build the project and JaCoCo coverage-tooling to
generate the coverage artifact.
You can check the Docker image configuration and scripts if you want to build your own image.
GitLab expects the artifact in the Cobertura format, so you have to execute a few
scripts before uploading it. The test-jdk11
job tests the code and generates an
XML artifact. The coverage-jdk-11
job converts the artifact into a Cobertura report:
test-jdk11:
stage: test
image: gradle:6.6.1-jdk11
script:
- 'gradle test jacocoTestReport' # jacoco must be configured to create an xml report
artifacts:
paths:
- build/jacoco/jacoco.xml
coverage-jdk11:
# Must be in a stage later than test-jdk11's stage.
# The `visualize` stage does not exist by default.
# Please define it first, or chose an existing stage like `deploy`.
stage: visualize
image: haynes/jacoco2cobertura:1.0.4
script:
# convert report from jacoco to cobertura
- 'python /opt/cover2cover.py build/jacoco/jacoco.xml src/main/java > build/cobertura.xml'
# read the <source></source> tag and prepend the path to every filename attribute
- 'python /opt/source2filename.py build/cobertura.xml'
needs: ["test-jdk11"]
dependencies:
- test-jdk11
artifacts:
reports:
cobertura: build/cobertura.xml
Python example
The following gitlab-ci.yml
example for Python uses pytest-cov to collect test coverage data and coverage.py to convert the report to use full relative paths.
The information isn't displayed without the conversion.
This example assumes that the code for your package is in src/
and your tests are in tests.py
:
run tests:
stage: test
image: python:3
script:
- pip install pytest pytest-cov
- pytest --cov=src/ tests.py
- coverage xml
artifacts:
reports:
cobertura: coverage.xml