add ini option to disable string escape for parametrization

AUTHORS

@@ -242,6 +242,7 @@ Vidar T. Fauske
 Virgil Dupras
 Vitaly Lashmanov
 Vlad Dragos
+Volodymyr Piskun
 Wil Cooley
 William Lee
 Wim Glenn

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

@@ -81,6 +81,21 @@ 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.

src/_pytest/python.py

@@ -102,6 +102,13 @@ def pytest_addoption(parser):
         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",
@@ -1156,6 +1163,16 @@ 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 ascii_escaped(val)
+
+
 def _idval(val, argname, idx, idfn, item, config):
     if idfn:
         try:
@@ -1177,7 +1194,7 @@ def _idval(val, argname, idx, idfn, item, config):
             return hook_id
 
     if isinstance(val, STRING_TYPES):
-        return ascii_escaped(val)
+        return _disable_escaping(val)
     elif isinstance(val, (float, int, bool, NoneType)):
         return str(val)
     elif isinstance(val, REGEX_TYPE):