Add coverage

tools/telemetry/third_party/coverage/doc/plugins.rst

+.. Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+.. For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt
+
+.. _plugins:
+
+=======
+Plugins
+=======
+
+.. :history: 20150124T143000, new page.
+.. :history: 20150802T174600, updated for 4.0b1
+
+
+Coverage.py's behavior can be extended with third-party plugins.  A plugin is a
+separately installed Python class that you register in your .coveragerc.
+Plugins can be used to implement coverage measurement for non-Python files.
+
+Information about using plugins is on this page.  To write a plugin, see
+:ref:`api_plugin`.
+
+.. versionadded:: 4.0
+
+
+Using plugins
+-------------
+
+To use a coverage.py plugin, you install it, and configure it.  For this
+example, let's say there's a Python package called ``something`` that provides a
+coverage.py plugin called ``something.plugin``.
+
+#. Install the plugin's package as you would any other Python package::
+
+    pip install something
+
+#. Configure coverage.py to use the plugin.  You do this by editing (or
+   creating) your .coveragerc file, as described in :ref:`config`.  The
+   ``plugins`` setting indicates your plugin.  It's a list of importable module
+   names of plugins::
+
+    [run]
+    plugins =
+        something.plugin
+
+#. If the plugin needs its own configuration, you can add those settings in
+   the .coveragerc file in a section named for the plugin::
+
+    [something.plugin]
+    option1 = True
+    option2 = abc.foo
+
+   Check the documentation for the plugin to see if it takes any options, and
+   what they are.
+
+#. Run your tests with coverage.py as you usually would.
+
+
+Available plugins
+-----------------
+
+Some coverage.py plugins you might find useful:
+
+* `Django template coverage.py plugin`__: for measuring coverage in Django
+  templates.
+
+  .. __: https://pypi.python.org/pypi/django_coverage_plugin
+
+* `Mako template coverage plugin`__: for measuring coverage in Mako templates.
+  Doesn't work yet, probably needs some changes in Mako itself.
+
+  .. __: https://bitbucket.org/ned/coverage-mako-plugin