add diffs in formatting job to artifacts

format:

  stage: analyze

  variables:

    ARTIFACT_BASE_NAME: "mr-$CI_MERGE_REQUEST_IID--sha-$CI_COMMIT_SHORT_SHA"

    ARTIFACT_FOLDER: "formatting-patch"

  tags:

    - linux

  allow_failure: true

  script:

    - isort --df --check --color --profile black . || ret_val_isort=$?

    - black --diff --check . || ret_val_black=$?

    - isort_diff_file="$ARTIFACT_BASE_NAME--isort-formatting-fix.patch"

    - isort --df --check --color --profile black . | tee $ARTIFACT_FOLDER/$isort_diff_files || ret_val_isort=$?

    - black_diff_file="$ARTIFACT_BASE_NAME--black-formatting-fix.patch"

    - black --diff --check . | tee $ARTIFACT_FOLDER/$black_diff_file || ret_val_black=$?

    - if [[ $ret_val_isort != 0 || $ret_val_black != 0 ]]; then exit 1; fi

  artifacts:

    paths:

      - "$ARTIFACT_FOLDER"

    when: on_failure

    name: "$ARTIFACT_BASE_NAME--formatting-patch"

    expose_as: "formatting patch"