roles/pycobertura-diff/tasks/main.yaml

- name: Ensure pycobertura is available
  pip:
    name: pycobertura
    extra_args: --user

- name: Prepare copy of the new version of sources
  shell: |
    set -ex
    NEW_WORK={{ ansible_user_dir }}/new
    mkdir "${NEW_WORK}"
    NEW_SRCDIR=${NEW_WORK}/{{ zuul.project.short_name }}
    pushd {{ zuul.project.src_dir }}
    git worktree add "${NEW_SRCDIR}" {{ zuul.branch }}
    popd

- name: Retrieve coverage from parent jobs
  get_url:
    url: "{{ item.url }}"
    dest: "{{ ansible_user_dir }}/new/coverage.xml"
  when:
    - item.metadata is defined
    - item.metadata.type is defined
    - item.metadata.type == "cobertura_xml"
  loop: "{{ zuul.artifacts }}"

- name: Generate pycobertura report
  shell: |
    set -ex
    PATH=${PATH}:~/.local/bin
    pycobertura show --format html --output "{{ ansible_user_dir }}/zuul-output/logs/coverage.html" \
      --source "{{ ansible_user_dir }}/new/{{ zuul.project.short_name }}" "{{ ansible_user_dir }}/new/coverage.xml"
    pycobertura diff --format html --output "{{ ansible_user_dir }}/zuul-output/logs/coverage-diff.html" \
      --source1 "{{ zuul.project.src_dir }}" "{{ coverage_xml_dir }}/coverage.xml" \
      --source2 "{{ ansible_user_dir }}/new/{{ zuul.project.short_name }}" "{{ ansible_user_dir }}/new/coverage.xml"
    sed -e 's;^  </body>$;    <p>Show <a href="coverage.html">final coverage</a> only</p>\n  </body>;' \
      -i "{{ ansible_user_dir }}/zuul-output/logs/coverage-diff.html"