Add verbosity_assertions and config.get_verbosity

Fixes #11387

doc/en/how-to/output.rst

@@ -286,6 +286,20 @@ situations, for example you are shown even fixtures that start with ``_`` if you
 Using higher verbosity levels (``-vvv``, ``-vvvv``, ...) is supported, but has no effect in pytest itself at the moment,
 however some plugins might make use of higher verbosity.
 
+.. _`pytest.fine_grained_verbosity`:
+
+Fine-grained verbosity
+~~~~~~~~~~~~~~~~~~~~~~
+
+In addition to specifying the application wide verbosity level, it is possible to control specific aspects independently.
+This is done by setting a verbosity level in the configuration file for the specific aspect of the output.
+
+:confval:`verbosity_assertions`: Controls how verbose the assertion output should be when pytest is executed. Running
+``pytest --no-header`` with a value of ``2`` would have the same output as the previous example, but each test inside
+the file is shown by a single character in the output.
+
+(Note: currently this is the only option available, but more might be added in the future).
+
 .. _`pytest.detailed_failed_tests_usage`:
 
 Producing a detailed summary report

doc/en/reference/reference.rst

@@ -1822,6 +1822,19 @@ passed multiple times. The expected format is ``name=value``. For example::
             clean_db
 
 
+.. confval:: verbosity_assertions
+
+    Set a verbosity level specifically for assertion related output, overriding the application wide level.
+
+    .. code-block:: ini
+
+        [pytest]
+        verbosity_assertions = 2
+
+    Defaults to application wide verbosity level (via the ``-v`` command-line option). A special value of
+    "auto" can be used to explicitly use the global verbosity level.
+
+
 .. confval:: xfail_strict
 
     If set to ``True``, tests marked with ``@pytest.mark.xfail`` that actually succeed will by default fail the