feat(toolchain) Add coveragepy configuration attribute

examples/bzlmod/.coveragerc

@@ -0,0 +1,8 @@
+[report]
+include_namespace_packages=True
+skip_covered = True
+[run]
+relative_files = True
+branch = True
+omit =
+	*/external/*

examples/bzlmod/BUILD.bazel

@@ -82,3 +82,5 @@ build_test(
     name = "all_requirements",
     targets = all_requirements,
 )
+
+exports_files([".coveragerc"])

examples/bzlmod/MODULE.bazel

@@ -22,6 +22,7 @@ bazel_dep(name = "protobuf", version = "24.4", repo_name = "com_google_protobuf"
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")
 python.toolchain(
     configure_coverage_tool = True,
+    coverage_rc = "//:.coveragerc",
     # Only set when you have mulitple toolchain versions.
     is_default = True,
     python_version = "3.9",

python/private/common/providers.bzl

@@ -73,6 +73,7 @@ def _PyRuntimeInfo_init(
         interpreter = None,
         files = None,
         coverage_tool = None,
+        coverage_rc = None,
         coverage_files = None,
         pyc_tag = None,
         python_version,
@@ -121,6 +122,7 @@ def _PyRuntimeInfo_init(
         "bootstrap_template": bootstrap_template,
         "coverage_files": coverage_files,
         "coverage_tool": coverage_tool,
+        "coverage_rc": coverage_rc,
         "files": files,
         "implementation_name": implementation_name,
         "interpreter": interpreter,
@@ -202,6 +204,12 @@ The files required at runtime for using `coverage_tool`. Will be `None` if no
 
 If set, this field is a `File` representing tool used for collecting code
 coverage information from python tests. Otherwise, this is `None`.
+""",
+        "coverage_rc": """
+:type: File | None
+
+If set, this field is a `File` representing the configuration file used by the
+coverage information from python tests. Otherwise, this is `None`.
 """,
         "files": """
 :type: depset[File] | None

python/private/common/py_executable.bzl

@@ -320,6 +320,8 @@ def _get_runtime_details(ctx, semantics):
                 direct.append(effective_runtime.coverage_tool)
             if effective_runtime.coverage_files:
                 transitive.append(effective_runtime.coverage_files)
+            if effective_runtime.coverage_rc:
+                direct.append(effective_runtime.coverage_rc)
         runtime_files = depset(direct = direct, transitive = transitive)
     else:
         runtime_files = depset()

python/private/common/py_executable_bazel.bzl

@@ -343,6 +343,10 @@ def _create_stage2_bootstrap(
         )
     else:
         coverage_tool_runfiles_path = ""
+    if runtime and runtime.coverage_rc:
+        coverage_rc_path = runtime.coverage_rc.path
+    else:
+        coverage_rc_path = ""
 
     template = runtime.stage2_bootstrap_template
 
@@ -351,6 +355,7 @@ def _create_stage2_bootstrap(
         output = output,
         substitutions = {
             "%coverage_tool%": coverage_tool_runfiles_path,
+            "%coverage_rc%": coverage_rc_path,
             "%import_all%": "True" if ctx.fragments.bazel_py.python_import_all_repositories else "False",
             "%imports%": ":".join(imports.to_list()),
             "%main%": "{}/{}".format(ctx.workspace_name, main_py.short_path),
@@ -403,6 +408,12 @@ def _create_stage1_bootstrap(
             subs["%shebang%"] = DEFAULT_STUB_SHEBANG
             template = ctx.file._bootstrap_template
 
+        if runtime and runtime.coverage_rc:
+            coverage_rc_path = runtime.coverage_rc.path
+        else:
+            coverage_rc_path = ""
+
+        subs["%coverage_rc%"] = coverage_rc_path
         subs["%coverage_tool%"] = coverage_tool_runfiles_path
         subs["%import_all%"] = ("True" if ctx.fragments.bazel_py.python_import_all_repositories else "False")
         subs["%imports%"] = ":".join(imports.to_list())

python/private/common/py_runtime_rule.bzl

@@ -77,6 +77,10 @@ def _py_runtime_impl(ctx):
     else:
         coverage_tool = None
         coverage_files = None
+    if ctx.attr.coverage_rc:
+        coverage_rc = ctx.attr.coverage_rc.files.to_list()[0]
+    else:
+        coverage_rc = None
 
     python_version = ctx.attr.python_version
 
@@ -117,6 +121,7 @@ def _py_runtime_impl(ctx):
     py_runtime_info_kwargs.update(dict(
         implementation_name = ctx.attr.implementation_name,
         interpreter_version_info = interpreter_version_info,
+        coverage_rc = coverage_rc,
         pyc_tag = pyc_tag,
         stage2_bootstrap_template = ctx.file.stage2_bootstrap_template,
         zip_main_template = ctx.file.zip_main_template,
@@ -216,6 +221,12 @@ of coverage.py (https://coverage.readthedocs.io), at least including
 the `run` and `lcov` subcommands.
 """,
         ),
+        "coverage_rc": attr.label(
+            allow_single_file = True,
+            doc = ".converage or pyproject.toml or " +
+                  "for configure coverage tool",
+            mandatory = False,
+        ),
         "files": attr.label_list(
             allow_files = True,
             doc = """

python/private/hermetic_runtime_repo_setup.bzl

@@ -27,7 +27,8 @@ def define_hermetic_runtime_toolchain_impl(
         extra_files_glob_exclude,
         python_version,
         python_bin,
-        coverage_tool):
+        coverage_tool,
+        coverage_rc):
     """Define a toolchain implementation for a python-build-standalone repo.
 
     It expected this macro is called in the top-level package of an extracted
@@ -47,6 +48,8 @@ def define_hermetic_runtime_toolchain_impl(
             repositoroy.
         coverage_tool: {type}`str` optional target to the coverage tool to
             use.
+        coverage_rc: {type}`str` optional target to the coverage rc file to
+            use.
     """
     _ = name  # @unused
     version_info = semver(python_version)
@@ -134,6 +137,7 @@ def define_hermetic_runtime_toolchain_impl(
         },
         # Convert empty string to None
         coverage_tool = coverage_tool or None,
+        coverage_rc = coverage_rc or None,
         python_version = "PY3",
         implementation_name = "cpython",
         # See https://peps.python.org/pep-3147/ for pyc tag infix format

python/private/python.bzl

@@ -319,6 +319,7 @@ def _create_toolchain_attrs_struct(*, tag = None, python_version = None, toolcha
         python_version = python_version if python_version else tag.python_version,
         configure_coverage_tool = getattr(tag, "configure_coverage_tool", False),
         ignore_root_user_error = getattr(tag, "ignore_root_user_error", False),
+        coverage_rc = getattr(tag, "coverage_rc", None),
     )
 
 def _get_bazel_version_specific_kwargs():
@@ -375,6 +376,10 @@ A toolchain's repository name uses the format `python_{major}_{minor}`, e.g.
                     mandatory = False,
                     doc = "Whether or not to configure the default coverage tool for the toolchains.",
                 ),
+                "coverage_rc": attr.label(
+                    mandatory = False,
+                    doc = "The coverage configuration file to use for the toolchains.",
+                ),
                 "ignore_root_user_error": attr.bool(
                     default = False,
                     doc = """\

python/private/python_bootstrap_template.txt

@@ -402,9 +402,11 @@ def _RunForCoverage(python_program, main_filename, args, env,
   """
   # We need for coveragepy to use relative paths.  This can only be configured
   unique_id = uuid.uuid4()
-  rcfile_name = os.path.join(os.environ['COVERAGE_DIR'], ".coveragerc_{}".format(unique_id))
-  with open(rcfile_name, "w") as rcfile:
-    rcfile.write('''[run]
+  rcfile_name = "%coverage_rc%"
+  if not rcfile_name:
+    rcfile_name = os.path.join(os.environ['COVERAGE_DIR'], ".coveragerc_{}".format(unique_id))
+    with open(rcfile_name, "w") as rcfile:
+      rcfile.write('''[run]
 relative_files = True
 ''')
   PrintVerboseCoverage('Coverage entrypoint:', coverage_entrypoint)

python/private/python_repositories.bzl

@@ -313,13 +313,15 @@ define_hermetic_runtime_toolchain_impl(
   python_version = {python_version},
   python_bin = {python_bin},
   coverage_tool = {coverage_tool},
+  coverage_rc = {coverage_rc},
 )
 """.format(
         extra_files_glob_exclude = render.list(glob_exclude),
         extra_files_glob_include = render.list(glob_include),
         python_bin = render.str(python_bin),
         python_version = render.str(rctx.attr.python_version),
         coverage_tool = render.str(coverage_tool),
+        coverage_rc = rctx.attr.coverage_rc,
     )
     rctx.delete("python")
     rctx.symlink(python_bin, "python")
@@ -329,6 +331,7 @@ define_hermetic_runtime_toolchain_impl(
     attrs = {
         "auth_patterns": rctx.attr.auth_patterns,
         "coverage_tool": rctx.attr.coverage_tool,
+        "coverage_rc": rctx.attr.coverage_rc,
         "distutils": rctx.attr.distutils,
         "distutils_content": rctx.attr.distutils_content,
         "ignore_root_user_error": rctx.attr.ignore_root_user_error,
@@ -381,6 +384,12 @@ For more information see the official bazel docs
 (https://bazel.build/reference/be/python#py_runtime.coverage_tool).
 """,
         ),
+        "coverage_rc": attr.label(
+            allow_single_file = True,
+            doc = ".converage or pyproject.toml or " +
+                  "for configure coverage tool",
+            mandatory = False,
+        ),
         "distutils": attr.label(
             allow_single_file = True,
             doc = "A distutils.cfg file to be included in the Python installation. " +
@@ -465,6 +474,7 @@ def python_register_toolchains(
         python_version,
         register_toolchains = True,
         register_coverage_tool = False,
+        coverage_rc = None,
         set_python_version_constraint = False,
         tool_versions = None,
         minor_mapping = None,
@@ -564,6 +574,7 @@ def python_register_toolchains(
             urls = urls,
             strip_prefix = strip_prefix,
             coverage_tool = coverage_tool,
+            coverage_rc = coverage_rc,
             **kwargs
         )
         if register_toolchains:

python/private/stage2_bootstrap_template.py

@@ -32,6 +32,7 @@
 IMPORT_ALL = True if "%import_all%" == "True" else False
 # Runfiles-relative path to the coverage tool entry point, if any.
 COVERAGE_TOOL = "%coverage_tool%"
+COVERAGE_RCFILE = "%coverage_rc%"
 
 # ===== Template substitutions end =====
 
@@ -344,14 +345,16 @@ def _maybe_collect_coverage(enable):
     coverage_dir = os.environ["COVERAGE_DIR"]
     unique_id = uuid.uuid4()
 
-    # We need for coveragepy to use relative paths.  This can only be configured
-    rcfile_name = os.path.join(coverage_dir, ".coveragerc_{}".format(unique_id))
-    with open(rcfile_name, "w") as rcfile:
-        rcfile.write(
-            """[run]
-relative_files = True
-"""
-        )
+    rcfile_name = COVERAGE_RCFILE
+    if not rcfile_name:
+        # We need for coveragepy to use relative paths.  This can only be configured
+        rcfile_name = os.path.join(coverage_dir, ".coveragerc_{}".format(unique_id))
+        with open(rcfile_name, "w") as rcfile:
+            rcfile.write(
+                """[run]
+    relative_files = True
+    """
+            )
     try:
         cov = coverage.Coverage(
             config_file=rcfile_name,