Source code for sciunit.capabilities

"""The base class for SciUnit capabilities.

By inheriting a capability class, a model tells the test that it implements
that capability and that all of its methods are safe to call.
The capability must then be implemented by the modeler (i.e. all of the
capabilty's methods must implemented in the model class).
"""

import dis
import inspect
import io
import re
import sys
import warnings

from .base import SciUnit, log, logger
from .errors import CapabilityNotImplementedError

# from sciunit.models.examples import ConstModel, UniformModel


class Capability(SciUnit):
    """Abstract base class for sciunit capabilities."""

    @classmethod
    def source_check(cls, model: "sciunit.Model") -> bool:
        required_methods = []
        default_cap_methods = ["unimplemented", "__str__"]
        source_capable = True

        for key, value in vars(cls).items():
            if inspect.isfunction(value) and key not in default_cap_methods:
                required_methods.append(key)

        for method in required_methods:
            try:
                stdout = sys.stdout
                sys.stdout = io.StringIO()

                dis.dis(getattr(cls, method))

                dis_output = sys.stdout.getvalue()
                sys.stdout = stdout

                dis_output = re.split("\n|\s+", dis_output)
                dis_output = [word for word in dis_output if word]

                if (
                    "(NotImplementedError)" in dis_output
                    or "(unimplemented)" in dis_output
                    or "(CapabilityNotImplementedError)" in dis_output
                    or "(NotImplemented)" in dis_output
                ):
                    cap_source = inspect.getsource(getattr(cls, method))
                    model_source = inspect.getsource(getattr(model, method))

                    if cap_source == model_source:
                        source_capable = False
                        break

            except OSError:
                warnings.warn(
                    """Inspect cannot get the source, and it is not guaranteed that 
                    all required methods have been implemented by the model"""
                )
                break

        return source_capable

    @classmethod
    def check(cls, model: "sciunit.Model", require_extra: bool = False) -> bool:
        """Check whether the provided model has this capability.

        By default, uses isinstance.  If `require_extra`, also requires that an
        instance check be present in `model.extra_capability_checks`.

        Args:
            model (Model): A sciunit model instance
            require_extra (bool, optional): Requiring that an instance check be present in
                                            `model.extra_capability_checks`. Defaults to False.

        Returns:
            bool: Whether the provided model has this capability.
        """

        class_capable = isinstance(model, cls)
        source_capable = None

        if class_capable:
            source_capable = cls.source_check(model)

        f_name = (
            model.extra_capability_checks.get(cls, None)
            if model.extra_capability_checks is not None
            else False
        )

        if f_name:
            f = getattr(model, f_name)
            instance_capable = f()
        elif not require_extra:
            instance_capable = True
        else:
            instance_capable = False

        if not class_capable:
            log(
                (
                    "The Model class does not claim at least one Capability required by "
                    "the Test class, so the Score is likely to be unavailable."
                )
            )
        elif not source_capable:
            logger.warning(
                (
                    "The model class claimed to implement all methods required by "
                    "the Test class, but at least one was left unimplemented, "
                    "so this model will be skipped."
                )
            )

        return class_capable and instance_capable and source_capable

    def unimplemented(self, message: str = "") -> None:
        """Raise a `CapabilityNotImplementedError` with details.

        Args:
            message (str, optional): Message for not implemented exception. Defaults to ''.

        Raises:
            CapabilityNotImplementedError: Raise a `CapabilityNotImplementedError` with details.
        """
        from sciunit import Model

        capabilities = [
            obj
            for obj in self.__class__.mro()
            if issubclass(obj, Capability) and not issubclass(obj, Model)
        ]
        model = self if isinstance(self, Model) else None
        capability = None if not capabilities else capabilities[0]
        raise CapabilityNotImplementedError(model, capability, message)

    class __metaclass__(type):
        @property
        def name(cls):
            return cls.__name__

    def __str__(self) -> str:
        return self.name


class ProducesNumber(Capability):
    """An example capability for producing some generic number."""

    def produce_number(self) -> None:
        """Produce a number."""
        self.unimplemented()


class Runnable(Capability):
    """Capability for models that can be run, i.e. simulated."""

    def run(self, **run_params) -> None:
        """Run, i.e. simulate the model."""
        self.unimplemented()

    def set_run_params(self, **run_params) -> None:
        """Set parameters for the next run.

        Note these are parameters of the simulation itself, not the model.
        """
        self.unimplemented()

    def set_default_run_params(self, **default_run_params) -> None:
        """Set default parameters for all runs.

        Note these are parameters of the simulation itself, not the model.
        """
        self.unimplemented()