build: add test coverage into pipeline + pre-commit

[dartanghan]

Hey team!

I've added pytest-cov to our pipeline and pre-commit. Unfortunately we are under 40%, so I placed a threshold of 35% to start.

• pre-commit edited and added a local pytest --cov command
• pyproject.toml adjusted and added a dependency group DEV
• pyproject.toml adjusted and pytest and pytest-cov added to DEV dep group
• test.yml CI pipeline edited and added coverage

The pytest-cov also tests the code, so I've replaced the pytest by pytest --cov

---

TOTAL 2355 1431 39%
Required test coverage of 35% reached. Total coverage: 39.24%

$ pre-commit
black................................................(no files to check)Skipped
ruff (legacy alias)..................................(no files to check)Skipped
check yaml...........................................(no files to check)Skipped
fix end of files.....................................(no files to check)Skipped
trim trailing whitespace.............................(no files to check)Skipped
test-coverage............................................................Passed

I hope this addition can be useful.

PS: in pipeline only 20% is covered. Reduced the threshold

[dartanghan]

Just noticed that pre-commit is also executed after the tests.

• Removed the tests from CI pipeline as pre-commit is called with tests + coverage
• Added an option pass_filenames: false which avoid to send all file names to pytest, so it wil test the whole structure.
• Kept the threshold in .pre-commit ( --cov-fail-under=20)

[dartanghan]

black....................................................................Passed
ruff (legacy alias)......................................................Passed
check yaml...............................................................Passed
fix end of files.........................................................Passed
trim trailing whitespace.................................................Passed
test+coverage............................................................Passed  

% uv run pytest --cov=src
Name                                          Stmts   Miss  Cover
-----------------------------------------------------------------
src/metis/__init__.py                             0      0   100%
src/metis/__main__.py                             3      3     0%
src/metis/cli/__init__.py                         0      0   100%
src/metis/cli/commands.py                        62     62     0%
src/metis/cli/entry.py                          149    149     0%
src/metis/cli/exporters.py                       91     91     0%
src/metis/cli/utils.py                          188    188     0%
src/metis/configuration.py                      105     83    21%
src/metis/engine/__init__.py                      2      0   100%
src/metis/engine/core.py                        318     99    69%
src/metis/engine/diff_utils.py                   29      1    97%
src/metis/engine/graphs/__init__.py               3      0   100%
src/metis/engine/graphs/ask.py                   34      1    97%
src/metis/engine/graphs/review.py               166     95    43%
src/metis/engine/graphs/schemas/__init__.py       2      0   100%
src/metis/engine/graphs/schemas/review.py        32      7    78%
src/metis/engine/graphs/types.py                 36      0   100%
src/metis/engine/graphs/utils.py                 79     22    72%
src/metis/engine/helpers.py                      43     17    60%
src/metis/exceptions.py                          18      4    78%
src/metis/plugin_loader.py                       98     71    28%
src/metis/plugins/__init__.py                     0      0   100%
src/metis/plugins/base.py                        17      5    71%
src/metis/plugins/c_plugin.py                    17      3    82%
src/metis/plugins/cpp_plugin.py                  18      5    72%
src/metis/plugins/go_plugin.py                   18      5    72%
src/metis/plugins/javascript_plugin.py           18      5    72%
src/metis/plugins/php_plugin.py                  18      5    72%
src/metis/plugins/python_plugin.py               17      4    76%
src/metis/plugins/ruby_plugin.py                 17     17     0%
src/metis/plugins/rust_plugin.py                 17      5    71%
src/metis/plugins/solidity_plugin.py             18     18     0%
src/metis/plugins/tb_plugin.py                   17      5    71%
src/metis/plugins/terraform_plugin.py            17      5    71%
src/metis/plugins/typescript_plugin.py           18      5    72%
src/metis/providers/__init__.py                   0      0   100%
src/metis/providers/azure_openai.py              52     52     0%
src/metis/providers/base.py                      17     17     0%
src/metis/providers/ollama.py                    20     20     0%
src/metis/providers/openai.py                    10     10     0%
src/metis/providers/openai_compatible.py        102    102     0%
src/metis/providers/registry.py                  38     38     0%
src/metis/providers/vllm.py                      14     14     0%
src/metis/sarif/__init__.py                       0      0   100%
src/metis/sarif/utils.py                         10      2    80%
src/metis/sarif/writer.py                        79      8    90%
src/metis/utils.py                              150     60    60%
src/metis/vector_store/__init__.py                0      0   100%
src/metis/vector_store/base.py                   29     13    55%
src/metis/vector_store/chroma_store.py           61     28    54%
src/metis/vector_store/pgvector_store.py         87     87     0%
src/metis/version.py                              1      0   100%
-----------------------------------------------------------------
TOTAL                                          2355   1431    39%

[mpekatsoula]

Thanks @dartanghan this looks good