Class IdMaker

src/_pytest/python.py:870–1088

Make IDs for a parametrization.

@final
@dataclasses.dataclass(frozen=True)
class IdMaker:
    """Make IDs for a parametrization."""

    __slots__ = (
        "argnames",
        "config",
        "idfn",
        "ids",
        "nodeid",
        "parametersets",
    )

    # The argnames of the parametrization.
    argnames: Sequence[str]
    # The ParameterSets of the parametrization.
    parametersets: Sequence[ParameterSet]
    # Optionally, a user-provided callable to make IDs for parameters in a
    # ParameterSet.
    idfn: Callable[[Any], object | None] | None
    # Optionally, explicit IDs for ParameterSets by index.
    ids: Sequence[object | None] | None
    # Optionally, the pytest config.
    # Used for controlling ASCII escaping, determining parametrization ID
    # strictness, and for calling the :hook:`pytest_make_parametrize_id` hook.
    config: Config | None
    # Optionally, the ID of the node being parametrized.
    # Used only for clearer error messages.
    nodeid: str | None

    def make_unique_parameterset_ids(self) -> list[str | _HiddenParam]:
        """Make a unique identifier for each ParameterSet, that may be used to
        identify the parametrization in a node ID.

        If strict_parametrization_ids is enabled, and duplicates are detected,
        raises CollectError. Otherwise makes the IDs unique as follows:

        Format is <prm_1_token>-...-<prm_n_token>[counter], where prm_x_token is
        - user-provided id, if given
        - else an id derived from the value, applicable for certain types
        - else <argname><parameterset index>
        The counter suffix is appended only in case a string wouldn&#x27;t be unique
        otherwise.
        """
        resolved_ids = list(self._resolve_ids())
        # All IDs must be unique!
        if len(resolved_ids) != len(set(resolved_ids)):
            # Record the number of occurrences of each ID.
            id_counts = Counter(resolved_ids)

            if self._strict_parametrization_ids_enabled():
                parameters = ", ".join(self.argnames)
                parametersets = ", ".join(
                    [saferepr(list(param.values)) for param in self.parametersets]
                )
                ids = ", ".join(
                    id if id is not HIDDEN_PARAM else "<hidden>" for id in resolved_ids
                )
                duplicates = ", ".join(