New helper function get_current_case_id to get the current case id for a given pytest request or item. Fixes #189.

Author: Sylvain MARIE

pytest_cases/__init__.py

@@ -22,7 +22,8 @@
 
 from .case_funcs import case, copy_case_info, set_case_id, get_case_id, get_case_marks, \
     get_case_tags, matches_tag_query, is_case_class, is_case_function
-from .case_parametrizer_new import parametrize_with_cases, THIS_MODULE, get_all_cases, get_parametrize_args
+from .case_parametrizer_new import parametrize_with_cases, THIS_MODULE, get_all_cases, get_parametrize_args, \
+    get_current_case_id
 
 try:
     # -- Distribution mode --
@@ -67,7 +68,7 @@
     'case', 'copy_case_info', 'set_case_id', 'get_case_id', 'get_case_marks',
     'get_case_tags', 'matches_tag_query', 'is_case_class', 'is_case_function',
     # test functions
-    'get_all_cases', 'parametrize_with_cases', 'THIS_MODULE', 'get_parametrize_args'
+    'get_all_cases', 'parametrize_with_cases', 'THIS_MODULE', 'get_parametrize_args', 'get_current_case_id'
 ]
 
 try:  # python 3.5+ type hints

pytest_cases/case_parametrizer_new.py

@@ -720,6 +720,38 @@ def _of_interest(x):  # noqa
     return cases
 
 
+def get_current_case_id(request_or_item,
+                        argnames  # type: str
+                        ):
+    """
+    A helper function to return the current case id for a given `pytest` item (available in some hooks) or `request`
+    (available in hooks, and also directly as a fixture).
+
+    You need to provide the argname(s) used in the corresponding `@parametrize_with_cases` so that this method finds
+    the right id.
+
+    :param request_or_item:
+    :param argnames:
+    :return:
+    """
+    try:
+        item = request_or_item.node
+    except AttributeError:
+        item = request_or_item
+
+    try:
+        # A LazyValue ?
+        lazy_val = item.callspec.params[argnames]
+    except KeyError:
+        # No: A fixture union created by `parametrize_plus_decorate`
+        main_fixture_style_template = "%s_%s"
+        fixture_union_name = main_fixture_style_template % (item.function.__name__, argnames)
+        return item.callspec.params[fixture_union_name].get_alternative_id()
+    else:
+        # A lazyvalue - confirmed
+        return lazy_val.get_id()
+
+
 # Below is the beginning of a switch from our code scanning tool above to the same one than pytest.
 # from .common_pytest import is_fixture, safe_isclass, compat_get_real_func, compat_getfslineno
 #

pytest_cases/tests/cases/doc/test_get_current_case_id.py

@@ -0,0 +1,24 @@
+from pytest_cases import parametrize_with_cases, fixture, get_current_case_id
+
+
+def data_b():
+    return 1
+
+
+@parametrize_with_cases("data", cases=data_b, prefix="data_")
+def test_lazy_val_case(data, request):
+    assert get_current_case_id(request, "data") == "b"
+
+
+@fixture
+def a():
+    return
+
+
+def data_a(a):
+    return 1
+
+
+@parametrize_with_cases("data", cases=data_a, prefix="data_")
+def test_fixture_case(data, request):
+    assert get_current_case_id(request.node, "data") == "a"