feat: [report] partial_also setting

Author: nedbat

CHANGES.rst

@@ -23,7 +23,7 @@ upgrading your version of coverage.py.
 Unreleased
 ----------
 
-- A new configuration option: ":ref:`[run] patch <config_run_patch>`" lets you
+- A new configuration option: ":ref:`config_run_patch`" lets you
   specify named patches to apply to work around some limitations in coverage
   measurement.  As of now, there is only one patch: ``os._exit`` lets coverage
   save its data even when :func:`os._exit() <python:os._exit>` is used to
@@ -34,6 +34,11 @@ Unreleased
   excluded as a line and ``if TYPE_CHECKING:`` is excluded as a branch.  Closes
   `issue 831`_.
 
+- A new configuration option: ":ref:`config_report_partial_also`" is a list of
+  regexes to add as pragmas for partial branches.  This parallels the
+  ":ref:`config_report_exclude_also`" setting for adding line exclusion
+  patterns.
+
 .. _issue 310: https://github.com/nedbat/coveragepy/issues/310
 .. _issue 312: https://github.com/nedbat/coveragepy/issues/312
 .. _issue 831: https://github.com/nedbat/coveragepy/issues/831

coverage/config.py

@@ -230,6 +230,7 @@ def __init__(self) -> None:
         self.report_omit: list[str] | None = None
         self.partial_always_list = DEFAULT_PARTIAL_ALWAYS[:]
         self.partial_list = DEFAULT_PARTIAL[:]
+        self.partial_also: list[str] = []
         self.precision = 0
         self.report_contexts: list[str] | None = None
         self.show_missing = False
@@ -413,6 +414,7 @@ def copy(self) -> CoverageConfig:
         ("include_namespace_packages", "report:include_namespace_packages", "boolean"),
         ("partial_always_list", "report:partial_branches_always", "regexlist"),
         ("partial_list", "report:partial_branches", "regexlist"),
+        ("partial_also", "report:partial_also", "regexlist"),
         ("precision", "report:precision", "int"),
         ("report_contexts", "report:contexts", "list"),
         ("report_include", "report:include", "list"),
@@ -546,6 +548,7 @@ def post_process(self) -> None:
             for k, v in self.paths.items()
         }
         self.exclude_list += self.exclude_also
+        self.partial_list += self.partial_also
 
     def debug_info(self) -> list[tuple[str, Any]]:
         """Make a list of (name, value) pairs for writing debug info."""

doc/config.rst

@@ -742,6 +742,22 @@ namespace packages`_, and are usually skipped.
 reporting.  See :ref:`source` for details.
 
 
+.. _config_report_partial_also:
+
+[report] partial_also
+.....................
+
+(multi-string) A list of regular expressions.  This setting is similar to
+:ref:`config_report_partial_branches`: it specifies patterns for branches to
+consider fully covered even if they don't exercise both destinations.  This
+setting is preferred, because it will preserve the default exclude patterns
+like ``pragma: no branch`` instead of overwriting them.
+
+See :ref:`config_report_partial_branches` for further details.
+
+.. versionadded:: 7.10.0
+
+
 .. _config_report_partial_branches:
 
 [report] partial_branches
@@ -751,7 +767,9 @@ reporting.  See :ref:`source` for details.
 one of these regexes is excused from being reported as a partial branch.  More
 details are in :ref:`branch`.  If you use this option, you are replacing all
 the partial branch regexes so you'll need to also supply the "pragma: no
-branch" regex if you still want to use it.
+branch" regex if you still want to use it. The
+:ref:`config_report_partial_also` setting can be used to specify patterns
+without overwriting the default set.
 
 
 .. _config_report_precision:

tests/test_config.py

@@ -493,6 +493,16 @@ def test_exclude_also(self) -> None:
         expected = coverage.config.DEFAULT_EXCLUDE + ["foobar", "raise .*Error"]
         assert cov.config.exclude_list == expected
 
+    def test_partial_also(self) -> None:
+        self.make_file("pyproject.toml", """\
+            [tool.coverage.report]
+            partial_also = ["foobar", "raise .*Error"]
+            """)
+        cov = coverage.Coverage()
+
+        expected = coverage.config.DEFAULT_PARTIAL + ["foobar", "raise .*Error"]
+        assert cov.config.partial_list == expected
+
     def test_core_option(self) -> None:
         # Test that the core option can be set in the configuration file.
         self.del_environ("COVERAGE_CORE")