add ini option to disable string escape for parametrization

AUTHORS

@@ -163,5 +163,6 @@ Victor Uriarte
 Vidar T. Fauske
 Vitaly Lashmanov
 Vlad Dragos
+Volodymyr Piskun
 Wouter van Ackooy
 Xuecong Liao

_pytest/python.py

@@ -81,6 +81,10 @@ def pytest_addoption(parser):
     parser.addini("python_functions", type="args", default=["test",],
         help="prefixes or glob names for Python test function and "
              "method discovery")
+    parser.addini("disable_test_id_escaping_and_forfeit_all_rights_to_community_support", type="bool",
+                  default=False, help="disable string escape non-ascii"
+                                      " characters, might cause unwanted side"
+                                      " effects(use at your own risk)")
 
     group.addoption("--import-mode", default="prepend",
         choices=["prepend", "append"], dest="importmode",
@@ -888,6 +892,14 @@ def _find_parametrized_scope(argnames, arg2fixturedefs, indirect):
     return 'function'
 
 
+def _disable_escaping(val, config=None):
+    if config is None:
+        escape_option = False
+    else:
+        escape_option = config.getini("disable_test_id_escaping_and_forfeit_all_rights_to_community_support")
+    return val if escape_option else _escape_strings(val)
+
+
 def _idval(val, argname, idx, idfn, config=None):
     if idfn:
         s = None
@@ -909,7 +921,7 @@ def _idval(val, argname, idx, idfn, config=None):
             return hook_id
 
     if isinstance(val, STRING_TYPES):
-        return _escape_strings(val)
+        return _disable_escaping(val, config)
     elif isinstance(val, (float, int, bool, NoneType)):
         return str(val)
     elif isinstance(val, REGEX_TYPE):

changelog/2482.feature

@@ -0,0 +1 @@
+Include new ``disable_test_id_escaping_and_forfeit_all_rights_to_community_support`` option to disable ascii-escaping in parametrized values. This may cause a series of problems and as the name makes clear, use at your own risk.

doc/en/parametrize.rst

@@ -78,6 +78,21 @@ them in turn::
     test_expectation.py:8: AssertionError
     ======= 1 failed, 2 passed in 0.12 seconds ========
 
+.. note::
+
+    pytest by default escapes any non-ascii characters used in unicode strings
+    for the parametrization because it has several downsides.
+    If however you would like to use unicode strings in parametrization, use this option in your ``pytest.ini``:
+
+    .. code-block:: ini
+
+        [pytest]
+        disable_test_id_escaping_and_forfeit_all_rights_to_community_support = True
+
+    to disable this behavior, but keep in mind that this might cause unwanted side effects and
+    even bugs depending on the OS used and plugins currently installed, so use it at your own risk.
+
+
 As designed in this example, only one pair of input/output values fails
 the simple test function.  And as usual with test function arguments,
 you can see the ``input`` and ``output`` values in the traceback.