Configuration for Python test coverage measurement.

Backend: pants.backend.python
Config section: [coverage-py]

Basic options


--coverage-py-filter="['<str>', '<str>', ...]"


default: []

A list of Python modules or filesystem paths to use in the coverage report, e.g. ['helloworld_test', 'helloworld/util/dirutil'].

Both modules and directory paths are recursive: any submodules or child paths, respectively, will be included.

If you leave this off, the coverage report will include every file in the transitive closure of the address/file arguments; for example, test :: will include every Python file in your project, whereas test project/app_test.py will include app_test.py and any of its transitive dependencies.


--coverage-py-report="[<CoverageReportType>, <CoverageReportType>, ...]"


one of: console, xml, html, raw, json, lcov

Which coverage report type(s) to emit.




default: False

If true, Pants will generate a global coverage report.

The global report will include all Python source files in the workspace and not just those depended on by the tests that were run.




default: None

Fail if the total combined coverage percentage for all tests is less than this number.

Use this instead of setting fail_under in a coverage.py config file, as the config will apply to each test separately, while you typically want this to apply to the combined coverage for all tests run.

Note that you must generate at least one (non-raw) coverage report for this check to trigger.

Note also that if you specify a non-integral value, you must also set [report] precision properly in the coverage.py config file to make use of the decimal places. See https://coverage.readthedocs.io/en/latest/config.html.

Advanced options




default: None

If specified, install the tool using the lockfile for this named resolve.

This resolve must be defined in [python].resolves, as described in Third-party dependencies.

The resolve's entire lockfile will be installed, unless specific requirements are listed via the requirements option, in which case only those requirements will be installed. This is useful if you don't want to invalidate the tool's outputs when the resolve incurs changes to unrelated requirements.

If unspecified, and the lockfile option is unset, the tool will be installed using the default lockfile shipped with Pants.

If unspecified, and the lockfile option is set, the tool will use the custom coverage-py "tool lockfile" generated from the version and extra_requirements options. But note that this mechanism is deprecated.


--coverage-py-requirements="['<str>', '<str>', ...]"


default: []

If install_from_resolve is specified, install these requirements, at the versions provided by the specified resolve's lockfile.

Values can be pip-style requirements (e.g., tool or tool==1.2.3 or tool>=1.2.3), or addresses of python_requirement targets (or targets that generate or depend on python_requirement targets).

The lockfile will be validated against the requirements - if a lockfile doesn't provide the requirement (at a suitable version, if the requirement specifies version constraints) Pants will error.

If unspecified, install the entire lockfile.


--coverage-py-interpreter-constraints="['<str>', '<str>', ...]"



Python interpreter constraints for this tool.




default: coverage

The console script for the tool. Using this option is generally preferable to (and mutually exclusive with) specifying an --entry-point since console script names have a higher expectation of staying stable across releases of the tool. Usually, you will not want to change this from the default.




default: None

The entry point for the tool. Generally you only want to use this option if the tool does not offer a --console-script (which this option is mutually exclusive with). Usually, you will not want to change this from the default.




default: {distdir}/coverage/python

Path to write the Pytest Coverage report to. Must be relative to the build root.




default: None

Path to an INI or TOML config file understood by coverage.py (https://coverage.readthedocs.io/en/stable/config.html).

Setting this option will disable [coverage-py].config_discovery. Use this option if the config is located in a non-standard location.




default: True

If true, Pants will include any relevant config files during runs (.coveragerc, setup.cfg, tox.ini, and pyproject.toml).

Use [coverage-py].config instead if your config is in a non-standard location.

Deprecated options




default: coverage[toml]>=6.5,<8

Deprecated, is scheduled to be removed in version: 2.18.0.dev1.
Custom tool versions are now installed from named resolves, as described at [Lockfiles](doc:python-lockfiles).

Requirement string for the tool.


--coverage-py-extra-requirements="['<str>', '<str>', ...]"


default: []

Deprecated, is scheduled to be removed in version: 2.18.0.dev1.
Custom tool versions are now installed from named resolves, as described at [Lockfiles](doc:python-lockfiles).

Any additional requirement strings to use with the tool. This is useful if the tool allows you to install plugins or if you need to constrain a dependency to a certain version.




default: <default>

Deprecated, is scheduled to be removed in version: 2.18.0.dev0.
Custom tool versions are now installed from named resolves, as described at [Lockfiles](doc:python-lockfiles).

  1. If you have an existing resolve that includes the requirements for this tool,
    you can set `[coverage-py].install_from_resolve = "<resolve name>".
    This may be the case if the tool also provides a runtime library, and you want
    to specify the version in just one place.
  2. If not, you can set up a new resolve as described at the link above.

Either way, the resolve you choose should provide the requirements currently set by the version and extra-requirements options for this tool, which you can see by running pants help-advanced coverage-py.

Path to a lockfile used for installing the tool.

Set to the string <default> to use a lockfile provided by Pants, so long as you have not changed the --version and --extra-requirements options, and the tool's interpreter constraints are compatible with the default. Pants will error or warn if the lockfile is not compatible (controlled by [python].invalid_lockfile_behavior). See https://github.com/pantsbuild/pants/blob/release_2.16.1rc4/src/python/pants/backend/python/subsystems/coverage_py.lock for the default lockfile contents.

Set to the string <none> to opt out of using a lockfile. We do not recommend this, though, as lockfiles are essential for reproducible builds and supply-chain security.

To use a custom lockfile, set this option to a file path relative to the build root, then run pants generate-lockfiles --resolve=coverage-py.

Alternatively, you can set this option to the path to a custom lockfile using pip's requirements.txt-style, ideally with --hash. Set [python].invalid_lockfile_behavior = 'ignore' so that Pants does not complain about missing lockfile headers.