Return the Coverage instance from process_startup

2 files changed, 11 insertions, 2 deletions

diff --git a/CHANGES.rst b/CHANGES.rst
index a6f0efa4..ff04775b 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -46,6 +46,9 @@ Unreleased
   functions, but now at least we raise a more specific error message, rather
   than getting confused. (`issue 456`_)
 
+- The `coverage.process_startup` function now returns the `Coverage` instance
+  it creates, as suggested in `issue 481`_.
+
 - Make a small tweak to how we compare threads, to avoid buggy custom
   comparison code in thread classes. (`issue 245`_)
 
@@ -58,6 +61,7 @@ Unreleased
 .. _issue 472: https://bitbucket.org/ned/coveragepy/issues/472/html-report-indents-incorrectly-for-one
 .. _issue 475: https://bitbucket.org/ned/coveragepy/issues/475/generator-expression-is-marked-as-not
 .. _issue 479: https://bitbucket.org/ned/coveragepy/issues/479/clarify-the-need-for-the-c-extension
+.. _issue 481: https://bitbucket.org/ned/coveragepy/issues/481/asyncioprocesspoolexecutor-tracing-not
 
 
 Version 4.1b2 --- 2016-01-23
diff --git a/coverage/control.py b/coverage/control.py
index e15b5a40..3e180745 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -1166,11 +1166,14 @@ def process_startup():
 
         import coverage; coverage.process_startup()
 
+    Returns the :class:`Coverage` instance that was started, or None if it was
+    not started by this call.
+
     """
     cps = os.environ.get("COVERAGE_PROCESS_START")
     if not cps:
         # No request for coverage, nothing to do.
-        return
+        return None
 
     # This function can be called more than once in a process. This happens
     # because some virtualenv configurations make the same directory visible
@@ -1185,10 +1188,12 @@ def process_startup():
     if hasattr(process_startup, "done"):
         # We've annotated this function before, so we must have already
         # started coverage.py in this process.  Nothing to do.
-        return
+        return None
 
     process_startup.done = True
     cov = Coverage(config_file=cps, auto_data=True)
     cov.start()
     cov._warn_no_data = False
     cov._warn_unimported_source = False
+
+    return cov