Improve Coverage.py configuration (#712)

Hide data files within a directory to avoid cluttering the repository
root, and minimize reports.

Author: adamchainz

.github/workflows/main.yml

@@ -46,7 +46,7 @@ jobs:
       uses: actions/upload-artifact@v7
       with:
         name: coverage-data-${{ matrix.python-version }}
-        path: '${{ github.workspace }}/.coverage.*'
+        path: '${{ github.workspace }}/.coverage/*'
         include-hidden-files: true
         if-no-files-found: error
 
@@ -70,7 +70,7 @@ jobs:
       - name: Download data
         uses: actions/download-artifact@v8
         with:
-          path: ${{ github.workspace }}
+          path: .coverage
           pattern: coverage-data-*
           merge-multiple: true
 

pyproject.toml

@@ -103,6 +103,7 @@ ini_options.xfail_strict = true
 
 [tool.coverage]
 run.branch = true
+run.data_file = ".coverage/cov"
 run.parallel = true
 run.source = [
   "pytest_randomly",
@@ -113,6 +114,8 @@ paths.source = [
   ".tox/**/site-packages",
 ]
 report.show_missing = true
+report.skip_covered = true
+report.skip_empty = true
 
 [tool.mypy]
 enable_error_code = [