fix: _exit is a better name for the patch than os._exit

Author: nedbat

CHANGES.rst

@@ -33,7 +33,7 @@ Unreleased
 
 - 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
+  measurement.  As of now, there is only one patch: ``_exit`` lets coverage
   save its data even when :func:`os._exit() <python:os._exit>` is used to
   abruptly end the process.  This closes long-standing `issue 310`_ as well as
   its duplicates: `issue 312`_, `issue 1845`_, and `issue 1941`_.

coverage/patch.py

@@ -21,7 +21,7 @@ def apply_patches(cov: Coverage, config: CoverageConfig) -> None:
     """Apply invasive patches requested by `[run] patch=`."""
 
     for patch in set(config.patch):
-        if patch == "os._exit":
+        if patch == "_exit":
             def _coverage_os_exit_patch(status: int) -> NoReturn:
                 try:
                     cov.save()

doc/config.rst

@@ -443,7 +443,7 @@ side-effects.
 
 Currently there is only one available patch:
 
-- ``os._exit``: The :func:`os._exit() <python:os._exit>` function exits the
+- ``_exit``: The :func:`os._exit() <python:os._exit>` function exits the
   process immediately without calling cleanup handlers.  This patch saves
   coverage data before exiting.
 

tests/test_config.py

@@ -474,7 +474,7 @@ def test_unknown_patch(self) -> None:
         self.make_file(".coveragerc", """\
             [run]
             patch =
-                os._exit
+                _exit
                 xyzzy
             """)
         msg = "Unknown patch 'xyzzy'"

tests/test_process.py

@@ -447,7 +447,7 @@ def test_os_exit(self, patch: bool) -> None:
             """)
         total_lines = 17
         if patch:
-            self.make_file(".coveragerc", "[run]\npatch = os._exit\n")
+            self.make_file(".coveragerc", "[run]\npatch = _exit\n")
         self.run_command("coverage run -p forky.py")
         self.run_command("coverage combine")
         data = coverage.CoverageData()