Pipeline Configure Coverage and Archive Reports

In this guide, you’ll learn how to set up a parallel code coverage job alongside unit tests in GitLab CI/CD, archive reports, and surface coverage metrics in the UI.

Base Unit Testing Job

This unit_testing job runs in the test stage, installs dependencies, executes tests, and collects JUnit reports:

stages:
  - test

variables:
  MONGO_URI: 'mongodb+srv://superCluster.d83jj.mongodb.net/superData'
  MONGO_USERNAME: superuser
  MONGO_PASSWORD: $M_DB_PASSWORD

unit_testing:
  stage: test
  image: node:17-alpine3.14
  before_script:
    - npm install
  script:
    - npm test
  artifacts:
    when: always
    expire_in: 3 days
    name: Moca-Test-Result
    paths:
      - test-results.xml
  reports:
    junit: test-results.xml

Adding a Parallel Code Coverage Job

Create a code_coverage job that reuses the Node.js image and installs dependencies. The npm run coverage command (powered by NYC) generates a Cobertura XML report.

code_coverage:
  stage: test
  image: node:17-alpine3.14
  before_script:
    - npm install
  script:
    - npm run coverage
  artifacts:
    name: Code-Coverage-Result
    when: always
    expire_in: 3 days
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml
  coverage: '/All files[^|]*\|[^|]*\s+([0-9.]+)%/'

Supported Artifact Report Types

GitLab CI/CD supports multiple report formats under artifacts:reports. Use the table below to choose the appropriate type:

Coverage Report Configuration

To enable GitLab’s built-in coverage display, specify the Cobertura format and the XML path in artifacts:reports:

artifacts:
  reports:
    coverage_report:
      coverage_format: cobertura
      path: coverage/cobertura-coverage.xml

Extracting Coverage Percentage

GitLab can parse test logs and extract a coverage percentage using a regular expression. For NYC’s “All files” summary line, use:

coverage: '/All files[^|]*\|[^|]*\s+([0-9.]+)%/'

Full CI Configuration with a Dependent Sample Job

Combine both jobs and add a sample-job that depends on code_coverage. This ensures downstream work only runs if coverage passes (or you enable allow_failure).

stages:
  - test

variables:
  MONGO_URI: 'mongodb+srv://superCluster.d83jj.mongodb.net/superData'
  MONGO_USERNAME: superuser
  MONGO_PASSWORD: $M_DB_PASSWORD

unit_testing:
  stage: test
  image: node:17-alpine3.14
  before_script:
    - npm install
  script:
    - npm test
  artifacts:
    when: always
    expire_in: 3 days
    name: Moca-Test-Result
    paths:
      - test-results.xml
  reports:
    junit: test-results.xml

code_coverage:
  stage: test
  image: node:17-alpine3.14
  before_script:
    - npm install
  script:
    - npm run coverage
  artifacts:
    name: Code-Coverage-Result
    when: always
    expire_in: 3 days
    reports:
      coverage_report:
        coverage_format: cobertura
        path: coverage/cobertura-coverage.xml
  coverage: '/All files[^|]*\|[^|]*\s+([0-9.]+)%/'

sample-job:
  stage: test
  needs:
    - code_coverage
  image: node:17-alpine3.14
  script:
    - echo "Running sample job"

Once you push this .gitlab-ci.yml, the GitLab pipeline graph clearly shows unit_testing, code_coverage, and sample-job in parallel:

Pipeline Execution and Coverage Failure

If the coverage threshold defined in your package.json isn’t met, the code_coverage job fails and downstream jobs are skipped by default.

Example logs from NYC:

> nyc --reporter cobertura --reporter lcov --reporter text --reporter json-summary mocha app-test.js --timeout 10000 --exit
...
ERROR: Coverage for lines (88.88%) does not meet global threshold (90%)
| File       | % Branch | % Funcs | % Lines | Uncovered Line #s |
|------------|----------|---------|---------|-------------------|
| All files  | 88.88    | 50      | 87.50   | 88.88             |

Your package.json might include:

{
  "scripts": {
    "coverage": "nyc --reporter cobertura --reporter lcov --reporter text --reporter json-summary mocha app-test.js"
  },
  "nyc": {
    "check-coverage": true,
    "lines": 90
  }
}

Coverage Percentage in the GitLab UI

With the coverage regex in place, GitLab extracts the percentage (e.g., 88.88%) and displays it in the pipeline view:

In this scenario, coverage is below the 90% threshold, causing code_coverage to fail and skipping sample-job:

Next, we’ll look at strategies to allow selective failures and continue pipeline execution even when coverage checks fail.