Access parametrization ids

AUTHORS

@@ -70,6 +70,7 @@ Benjamin Schubert
 Bernard Pratz
 Bo Wu
 Bob Ippolito
+Brendan Cazier
 Brian Dorsey
 Brian Larsen
 Brian Maissy

changelog/13907.improvement.rst

@@ -0,0 +1 @@
+Added a new attribute to the Callspec2 class with the stringified (either automatically or with an explicit `ids` parameter) ID of parametrization values.

src/_pytest/python.py

@@ -1113,6 +1113,8 @@ class CallSpec2:
  _idlist: Sequence[str] = dataclasses.field(default_factory=tuple)
  # Marks which will be applied to the item.
  marks: list[Mark] = dataclasses.field(default_factory=list)
+ # Parametrization mapping for each argname to an ID.
+ ids: dict[str | tuple[str, ...], str] = dataclasses.field(default_factory=dict)
 
  def setmulti(
  self,
@@ -1142,6 +1144,14 @@ def setmulti(
  _arg2scope=arg2scope,
  _idlist=self._idlist if id is HIDDEN_PARAM else [*self._idlist, id],
  marks=[*self.marks, *normalize_mark_list(marks)],
+ ids=self.ids
+ if id is HIDDEN_PARAM
+ else {
+ **self.ids,
+ _argnames[0]
+ if len(_argnames := tuple(argnames)) == 1
+ else _argnames: id,
+ },
  )
 
  def getparam(self, name: str) -> object:

testing/test_mark.py

@@ -1090,6 +1090,50 @@ def test_parameterset_for_parametrize_bad_markname(pytester: Pytester) -> None:
  test_parameterset_for_parametrize_marks(pytester, "bad")
 
 
+def test_parametrization_callspec_ids(pytester: Pytester):
+ pytester.makepyfile(
+ """
+import pytest
+
+class CustomClass:
+ pass
+
+def custom_function():
+ return None
+
+all_ids = [
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "first"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "2"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "3.5"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "True"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "<lambda>"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "CustomClass"},
+ {("tuple_one", "tuple_two"): "t1a-t2a", "id_function": "11", "id_explicit": "one", "name": "custom_function"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "first"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "2"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "3.5"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "True"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "<lambda>"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "CustomClass"},
+ {("tuple_one", "tuple_two"): "t1b-t2b", "id_function": "11", "id_explicit": "one", "name": "custom_function"}
+]
+
+@pytest.mark.parametrize("name", ("first", 2, 3.5, True, lambda k: k, CustomClass, custom_function))
+@pytest.mark.parametrize("id_explicit", (1,), ids=("one",))
+@pytest.mark.parametrize("id_function", (1,), ids=lambda k: f"{k}{k}")
+@pytest.mark.parametrize(("tuple_one", "tuple_two"), (("t1a", "t2a"), ("t1b", "t2b")))
+def test_more(name, id_explicit, id_function, tuple_one, tuple_two, request):
+ ids = request.node.callspec.ids
+ assert ids in all_ids
+"""
+ )
+
+ reprec = pytester.inline_run()
+ passed, skipped, failed = reprec.countoutcomes()
+ assert passed == 14
+ assert skipped == failed == 0
+
+
 def test_mark_expressions_no_smear(pytester: Pytester) -> None:
  pytester.makepyfile(
  """