Flutter GitLab CI to test, analyze, and run coverage report

gitlab-ci.yml

image: cirrusci/flutter:stable

before_script:
  - flutter pub get
  - flutter clean
  - flutter --version
  - flutter pub global activate junitreport

stages:
  - analyze-and-test

analyze-and-test:
  stage: analyze-and-test
  script:
    - export PATH="$PATH":"$HOME/.pub-cache/bin"
    - flutter build aot
    - flutter analyze
   # - flutter test
    - flutter test --machine | tojunit -o report.xml
    - flutter test --coverage ./lib 
    - lcov -r coverage/lcov.info '*/__test*__/*' -o coverage/lcov_cleaned.info
    - genhtml coverage/lcov_cleaned.info --output=coverage
  artifacts:
    when: always
    paths:
      - rspec.xml
      - coverage
    reports:
      junit:
        - report.xml
  only:
    - master
    - merge_requests
  except:
     variables:
       - $CI_MERGE_REQUEST_TARGET_BRANCH_NAME != "master"   

You'll need to set a regex line in your Settings->CI->General to have the coverage output returned on the result in the PR screen.