Coveralls JSON Output

If you are using Coveralls, you can get a coverage report in a suitable JSON format via the --coveralls<gcovr --coveralls> option:

gcovr --coveralls coverage.json

The --coveralls-pretty<gcovr --coveralls-pretty> option generates an indented JSON output that is easier to read.

Keep in mind that the output contains the checksums of the source files. If you are using different OSes, the line endings shall be the same.

If available, environment variable COVERALLS_REPO_TOKEN will be consumed and baked into the JSON output.

If running in a CI additional variables are used:

In Travis CI:
- TRAVIS_JOB_ID
- TRAVIS_BUILD_NUMBER
- TRAVIS_PULL_REQUEST
- TRAVIS_COMMIT
- TRAVIS_BRANCH
In Appveyor:
- APPVEYOR_JOB_ID
- APPVEYOR_JOB_NUMBER
- APPVEYOR_PULL_REQUEST_NUMBER
- APPVEYOR_REPO_COMMIT
- APPVEYOR_REPO_BRANCH
In Jenkins CI:
- JOB_NAME
- BUILD_ID
- CHANGE_ID
- GIT_COMMIT (if available)
- BRANCH_NAME
In GitHub Actions:
- GITHUB_WORKFLOW
- GITHUB_RUN_ID
- GITHUB_SHA
- GITHUB_HEAD_REF (if available)
- GITHUB_REF

The Coveralls JSON format is documented at https://docs.coveralls.io/api-introduction.

5.0 Added --coveralls<gcovr --coveralls> and --coveralls-pretty<gcovr --coveralls-pretty>.