Add new coverage component

Author: kdeldycke

changelog.md

@@ -8,7 +8,9 @@
 - **Breaking:** the Codecov integration is removed, along with the `codecov` component, its `.github/codecov.yaml`, and the `coverage_cells` metadata key. `repomatic init` prunes an untouched orphaned config; delete the `CODECOV_TOKEN` secret and coverage badge by hand.
 - **Breaking:** attestation bundles now carry the full filename of the asset they attest, so `repomatic-manpages.attestation.json` becomes `repomatic-manpages.tar.gz.attestation.json`. A repository declaring one extra asset gets `<filename>.attestation.json` in place of `<package-name>-extra-assets.attestation.json`.
 - New `pack-attestation` command names an attestation bundle after the asset it attests and prints the release upload list.
+- New `coverage` component: `repomatic init coverage` writes a `[tool.coverage]` section carrying branch coverage, report precision and a `report.fail_under` ratchet, shipped disabled.
 - The test suite now fails below the `[tool.coverage] report.fail_under` coverage floor, set to `78` for this project.
+- The bundled pytest config drops `--cov-branch` and `--cov-precision` from `addopts`, now carried by the `coverage` component. Existing `[tool.pytest]` sections are left alone; run `repomatic init coverage` to pick the settings back up.
 - The release lane's `publish-release` job now checks out the repository, so uploading binaries to the release no longer fails with `Failed to spawn: repomatic`. `7.7.0` shipped with no standalone executables because of it.
 - `lint-changelog` re-confirms a release live before dropping its availability admonition, so a day-old cache no longer reports a just-published version as missing.
 - The readme's logo is now an absolute URL, so it renders on the PyPI project page instead of 404ing.

repomatic/data/coverage.toml

@@ -0,0 +1,24 @@
+# Coverage.py configuration for Python projects.
+#
+# Native format - the keys coverage.py reads. When merged into pyproject.toml
+# via `repomatic init coverage`, the [tool.coverage] prefix is added
+# automatically.
+#
+# Pairs with the pytest config (`repomatic init pytest`), which turns coverage
+# on and names what to measure. *What* is measured is a pytest flag; *how* it
+# is measured and reported belongs here.
+
+# https://coverage.readthedocs.io/en/latest/config.html
+run.branch = true
+report.precision = 2
+# Coverage ratchet: the suite fails below this percentage, 0 disables it.
+# Raise it to a few points under the number your suite actually reaches: close
+# enough to catch a real regression, loose enough to absorb the spread across
+# an OS matrix.
+#
+# Set the floor here and nowhere else. A --cov-fail-under flag outranks this
+# value, so passing one from a CI workflow silently shadows whatever a project
+# configures. The two runs not meant to clear a full-suite floor opt out
+# explicitly instead: a partial CI slice with --cov-fail-under=0, and a focused
+# local run with --no-cov.
+report.fail_under = 0

repomatic/data/pytest.toml

@@ -10,13 +10,11 @@
 addopts = [
     # Show the N slowest tests.
     "--durations=10",
-    # Coverage settings - customize the package name for your project. Set the
-    # coverage floor in [tool.coverage] as report.fail_under, never here and
-    # never from CI: a --cov-fail-under flag outranks that config and shadows
-    # it. Runs not meant to clear it (a focused local run) pass --no-cov.
+    # Turn coverage on and name what to measure: customize this to your own
+    # package. Everything about *how* coverage is measured and reported (branch
+    # coverage, precision, and the report.fail_under ratchet) lives in
+    # [tool.coverage] instead, via `repomatic init coverage`.
     "--cov=.",
-    "--cov-branch",
-    "--cov-precision=2",
     "--cov-report=term",
     # Run tests in parallel across all logical cores. Requires the
     # pytest-xdist[psutil] test dependency.

repomatic/registry.py

@@ -792,6 +792,15 @@ def _workflow_entry(
         insert_after=("tool.ruff", "tool.ruff.format"),
         insert_before=("tool.mypy",),
     ),
+    ToolConfigComponent(
+        name="coverage",
+        description="Coverage.py measurement and reporting configuration",
+        init_default=InitDefault.EXPLICIT,
+        source_file="coverage.toml",
+        tool_section="tool.coverage",
+        insert_after=("tool.pytest",),
+        insert_before=("tool.mdformat", "tool.bumpversion"),
+    ),
     ToolConfigComponent(
         name="mypy",
         description="Mypy type checking configuration",

tests/test_init_project.py

@@ -295,13 +295,18 @@ def test_exportable_file_loadable(filename: str) -> None:
 #   have extras.
 _TEMPLATE_EXCLUDE_KEYS: dict[str, frozenset[str]] = {
     "bumpversion": frozenset({"current_version"}),
+    # The template ships the coverage ratchet disabled (`fail_under = 0`), so
+    # adopting a repomatic release never fails a downstream build on a floor
+    # its author never picked. This repository sets its own.
+    "coverage": frozenset({"fail_under"}),
     "mypy": frozenset(),
     "pytest": frozenset({"addopts"}),
     "ruff": frozenset({"extend-include"}),
     "typos": frozenset(),
 }
 _TEMPLATE_SUPERSET_KEYS: dict[str, frozenset[str]] = {
     "bumpversion": frozenset({"files"}),
+    "coverage": frozenset(),
     "mypy": frozenset(),
     "pytest": frozenset(),
     "ruff": frozenset(),
@@ -410,6 +415,12 @@ def _lookup(parsed: dict, key: str):
         # an installed copy of the package.
         ("pytest.toml", "testpaths", ["tests"]),
         ("pytest.toml", "xfail_strict", True),
+        # Coverage measurement and reporting, moved out of the pytest addopts
+        # so they sit where coverage.py itself reads them.
+        ("coverage.toml", "run.branch", True),
+        ("coverage.toml", "report.precision", 2),
+        # The ratchet ships disabled: a downstream repo opts in by raising it.
+        ("coverage.toml", "report.fail_under", 0),
     ),
 )
 def test_template_setting(template: str, key: str, expected) -> None:
@@ -423,7 +434,6 @@ def test_template_setting(template: str, key: str, expected) -> None:
         ("ruff.toml", "lint.ignore", "D400"),
         ("ruff.toml", "lint.ignore", "ERA001"),
         ("pytest.toml", "addopts", "--durations=10"),
-        ("pytest.toml", "addopts", "--cov-branch"),
         ("pytest.toml", "addopts", "--cov-report=term"),
         ("pytest.toml", "addopts", "--numprocesses=auto"),
         ("pytest.toml", "addopts", "--import-mode=importlib"),