Diff cov lint

Linting and coverage reports for git diff only.

Usage:

diff-cov-lint master new_branch --cov_report=coverage.xml --lint_report=pylint_output.txt

Example output (the command above was run in tests/repo folder):

======================== DIFF COVERAGE ========================
FILE                                    COVERED STMTS   PERCENT
src/add.py                                    5     8     62.5%
src/modify.py                                 1     2     50.0%
===============================================================
TOTAL DIFF COV                                6    10     60.0%

========================== DIFF LINT ==========================
src/add.py:10:0 E0602: Undefined variable 'this_line_makes_no_sense' (undefined-variable)

Arguments:

POSITIONAL ARGUMENTS
TARGET_REF Target branch in repo
SOURCE_REF Source branch in repo

FLAGS
--cov_report=COV_REPORT
Path to coverage report in Cobertura (pytest-cov) format, If not stated, coverage report will not be produced.
--lint_report=LINT_REPORT
Path to pylint report. If not stated, linting report will not be produced.
--repo_path=REPO_PATH
Path to repo folder, defaults to "."

CI Setup

This project's repo uses diff-cov-lint itself. You might want to check .gitlab-ci.yml for full configuration.

The scenario is following:

• Run tests on each push (test job)
• Calculate diff coverage and produce diff pylint reports for merge requests (code_quality_diff job)
• Get coverage and pylint report on full code on master and tags or manually on any push. (code_quality_full job)

Test job:

test: 
    stage: test
    script: 
        - pytest --cov=your_source_folder --cov-report xml tests # run pytest and produce xml report
    artifacts:
        paths: 
            - coverage.xml # save xml report to use it in further jobs
    only:
        - tags  # tags and branches are default values of "only", so preserve them
        - branches
        - merge_requests # add merge_requests since code_quality_diff job will use artifacts of this job

Diff code quality job:

code_quality_diff: 
    stage: code_quality_diff
    script:
        - git fetch -a # fetch all branches to calculate diff
        - pip install diff-cov-lint # install diff-cov-lint
        - pylint --exit-zero diff_cov_lint > pylint_output.txt # get pylint report. --exit-zero needed for job not to fail if pylint give score less than 10.
        - diff-cov-lint origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME origin/$CI_MERGE_REQUEST_SOURCE_BRANCH_NAME --cov_report coverage.xml --lint_report pylint_output.txt # run diff-cov-lint on diff between target branch and source branch. coverage.xml is used from the artifact.
    only:
        - merge_requests

Full code quality job:

code_quality_full:
    stage:
        code_quality_full
    script:
        - pytest --cov=your_source_folder tests # simply run pytest with coverage and pylint as usual
        - pylint --exit-zero diff_cov_lint
    rules:
        - if: '$CI_COMMIT_REF_NAME == "master"'
        - if: $CI_MERGE_REQUEST_ID
          when: never #otherwise this job will stuck for merge requests
        - when: manual # use manual to make this job optional.