climate_ref.testing

Testing utilities for running and validating diagnostic test cases.

This module provides: - Path resolution for package-local test data (catalogs, regression data) - Sample data fetching utilities - TestCaseRunner for executing diagnostics with test data - Drift-checking helpers for test-case regression baselines (assert_test_case_no_drift and the create_no_drift_test factory used by every provider's integration test module)

TEST_DATA_DIR = _determine_test_directory() module-attribute

Path to the centralised test data directory (for sample data).

TestCaseRunner

Helper class for running diagnostic test cases.

This runner handles: - Running the diagnostic with pre-resolved datasets - Setting up the execution definition

Source code in packages/climate-ref/src/climate_ref/testing.py

@define
class TestCaseRunner:
    """
    Helper class for running diagnostic test cases.

    This runner handles:
    - Running the diagnostic with pre-resolved datasets
    - Setting up the execution definition
    """

    config: Config
    datasets: ExecutionDatasetCollection | None = None

    def run(
        self,
        diagnostic: Diagnostic,
        test_case_name: str = "default",
        output_dir: Path | None = None,
        clean: bool = False,
    ) -> ExecutionResult:
        """
        Run a specific test case for a diagnostic.

        Parameters
        ----------
        diagnostic
            The diagnostic to run
        test_case_name
            Name of the test case to run (default: "default")
        output_dir
            Optional output directory for results
        clean
            If True, delete the output directory before running

        Returns
        -------
        ExecutionResult
            The result of running the diagnostic

        Raises
        ------
        NoTestDataSpecError
            If the diagnostic has no test_data_spec
        TestCaseNotFoundError
            If the test case doesn't exist
        DatasetResolutionError
            If datasets cannot be resolved
        """
        if diagnostic.test_data_spec is None:
            raise NoTestDataSpecError(f"Diagnostic {diagnostic.slug} has no test_data_spec")

        if not diagnostic.test_data_spec.has_case(test_case_name):
            raise TestCaseNotFoundError(
                f"Test case {test_case_name!r} not found. Available: {diagnostic.test_data_spec.case_names}"
            )

        if self.datasets is None:
            raise DatasetResolutionError(
                "No datasets provided. Run 'ref test-cases fetch' first to build the catalog."
            )

        # Validate that all non-empty collections have the required 'path' column
        for src_type, collection in self.datasets.items():
            if len(collection.datasets) > 0 and "path" not in collection.datasets.columns:
                raise DatasetResolutionError(
                    f"Datasets for '{src_type}' are missing the required 'path' column. "
                    f"Run 'ref test-cases fetch' to generate the paths file."
                )

        # Determine output directory
        if output_dir is None:
            output_dir = (
                self.config.paths.results
                / "test-cases"
                / diagnostic.provider.slug
                / diagnostic.slug
                / test_case_name
            )

        if clean and output_dir.exists():
            shutil.rmtree(output_dir)

        output_dir.mkdir(parents=True, exist_ok=True)

        definition = ExecutionDefinition(
            diagnostic=diagnostic,
            key=f"test-{test_case_name}",
            datasets=self.datasets,
            output_directory=output_dir,
            root_directory=output_dir.parent,
        )

        # Run the diagnostic with the regression-capture hook enabled, so the native output is
        # normalised (prepare_regression_output) before the bundle is built and captured.
        return diagnostic.run(definition, capture_regression=True)

run(diagnostic, test_case_name='default', output_dir=None, clean=False)

Run a specific test case for a diagnostic.

Parameters:

Name	Type	Description	Default
diagnostic	Diagnostic	The diagnostic to run	required
test_case_name	str	Name of the test case to run (default: "default")	'default'
output_dir	Path | None	Optional output directory for results	None
clean	bool	If True, delete the output directory before running	False

Returns:

Type	Description
ExecutionResult	The result of running the diagnostic

Raises:

Type	Description
NoTestDataSpecError	If the diagnostic has no test_data_spec
TestCaseNotFoundError	If the test case doesn't exist
DatasetResolutionError	If datasets cannot be resolved

Source code in packages/climate-ref/src/climate_ref/testing.py

def run(
    self,
    diagnostic: Diagnostic,
    test_case_name: str = "default",
    output_dir: Path | None = None,
    clean: bool = False,
) -> ExecutionResult:
    """
    Run a specific test case for a diagnostic.

    Parameters
    ----------
    diagnostic
        The diagnostic to run
    test_case_name
        Name of the test case to run (default: "default")
    output_dir
        Optional output directory for results
    clean
        If True, delete the output directory before running

    Returns
    -------
    ExecutionResult
        The result of running the diagnostic

    Raises
    ------
    NoTestDataSpecError
        If the diagnostic has no test_data_spec
    TestCaseNotFoundError
        If the test case doesn't exist
    DatasetResolutionError
        If datasets cannot be resolved
    """
    if diagnostic.test_data_spec is None:
        raise NoTestDataSpecError(f"Diagnostic {diagnostic.slug} has no test_data_spec")

    if not diagnostic.test_data_spec.has_case(test_case_name):
        raise TestCaseNotFoundError(
            f"Test case {test_case_name!r} not found. Available: {diagnostic.test_data_spec.case_names}"
        )

    if self.datasets is None:
        raise DatasetResolutionError(
            "No datasets provided. Run 'ref test-cases fetch' first to build the catalog."
        )

    # Validate that all non-empty collections have the required 'path' column
    for src_type, collection in self.datasets.items():
        if len(collection.datasets) > 0 and "path" not in collection.datasets.columns:
            raise DatasetResolutionError(
                f"Datasets for '{src_type}' are missing the required 'path' column. "
                f"Run 'ref test-cases fetch' to generate the paths file."
            )

    # Determine output directory
    if output_dir is None:
        output_dir = (
            self.config.paths.results
            / "test-cases"
            / diagnostic.provider.slug
            / diagnostic.slug
            / test_case_name
        )

    if clean and output_dir.exists():
        shutil.rmtree(output_dir)

    output_dir.mkdir(parents=True, exist_ok=True)

    definition = ExecutionDefinition(
        diagnostic=diagnostic,
        key=f"test-{test_case_name}",
        datasets=self.datasets,
        output_directory=output_dir,
        root_directory=output_dir.parent,
    )

    # Run the diagnostic with the regression-capture hook enabled, so the native output is
    # normalised (prepare_regression_output) before the bundle is built and captured.
    return diagnostic.run(definition, capture_regression=True)

assert_test_case_no_drift(config, diagnostic, test_case_name, paths, work_dir)

Execute a diagnostic test case and assert its committed bundle has not drifted.

Runs the diagnostic against the fetched catalog using the same execute/build stages as ref test-cases run (see :mod:climate_ref.cli.test_cases._stages), rebuilds the committed bundle from the fresh execution, and compares it to the tracked regression/ baseline within tolerance.

Unlike ref test-cases replay this re-executes the diagnostic rather than replaying, so it also proves the diagnostic still runs and emits a valid bundle.

Ingesting a committed bundle into the database is a separate concern, covered by the executor result-handling tests (packages/climate-ref/tests/unit/executor/test_result_handling.py and friends). It is intentionally not re-checked here.

Parameters:

Name	Type	Description	Default
config	Config	The active configuration (provides the software root and results dir).	required
diagnostic	Diagnostic	The diagnostic to run.	required
test_case_name	str	Name of the test case to run.	required
paths	TestCasePaths	Resolved paths for the test case (catalog + tracked regression baseline).	required
work_dir	Path	A per-test scratch directory for the output slot and execution outputs.	required

Raises:

Type	Description
NoTestDataSpecError	If the diagnostic has no test_data_spec.
TestCaseNotFoundError	If the test case doesn't exist.
AssertionError	If the rebuilt committed bundle drifts from the tracked baseline.

Source code in packages/climate-ref/src/climate_ref/testing.py

def assert_test_case_no_drift(
    config: Config,
    diagnostic: Diagnostic,
    test_case_name: str,
    paths: TestCasePaths,
    work_dir: Path,
) -> None:
    """
    Execute a diagnostic test case and assert its committed bundle has not drifted.

    Runs the diagnostic against the fetched catalog using the same execute/build stages as
    ``ref test-cases run`` (see :mod:`climate_ref.cli.test_cases._stages`),
    rebuilds the committed bundle from the fresh execution,
    and compares it to the tracked ``regression/`` baseline within tolerance.

    Unlike ``ref test-cases replay`` this re-executes the diagnostic rather than replaying,
    so it also proves the diagnostic still runs and emits a valid bundle.

    Ingesting a committed bundle into the database is a separate concern,
    covered by the executor result-handling tests
    (``packages/climate-ref/tests/unit/executor/test_result_handling.py`` and friends).
    It is intentionally not re-checked here.

    Parameters
    ----------
    config
        The active configuration (provides the software root and results dir).
    diagnostic
        The diagnostic to run.
    test_case_name
        Name of the test case to run.
    paths
        Resolved paths for the test case (catalog + tracked regression baseline).
    work_dir
        A per-test scratch directory for the output slot and execution outputs.

    Raises
    ------
    NoTestDataSpecError
        If the diagnostic has no test_data_spec.
    TestCaseNotFoundError
        If the test case doesn't exist.
    AssertionError
        If the rebuilt committed bundle drifts from the tracked baseline.
    """
    from climate_ref.cli.test_cases._stages import (  # noqa: PLC0415
        baseline_placeholders,
        stage_build,
        stage_compare,
        stage_execute,
    )

    if diagnostic.test_data_spec is None:
        raise NoTestDataSpecError(f"Diagnostic {diagnostic.slug} has no test_data_spec")

    if not diagnostic.test_data_spec.has_case(test_case_name):
        raise TestCaseNotFoundError(
            f"Test case {test_case_name!r} not found. Available: {diagnostic.test_data_spec.case_names}"
        )

    tc = diagnostic.test_data_spec.get_case(test_case_name)
    datasets = load_datasets_from_yaml(paths.catalog)

    slot = work_dir / "slot"
    slot.mkdir(parents=True, exist_ok=True)
    placeholders = baseline_placeholders(paths, config)

    # stage_execute runs the diagnostic (raising if it is not successful)
    # and copies the curated native set into the slot
    # stage_build rebuilds the committed bundle from it.
    source = stage_execute(
        config=config,
        diag=diagnostic,
        tc=tc,
        datasets=datasets,
        slot=slot,
        execution_dir=work_dir / "exec",
        clean=True,
    )
    stage_build(slot=slot, source=source, placeholders=placeholders)

    expected = Manifest.load(paths.manifest).committed
    failures, _ = stage_compare(slot=slot, paths=paths, slug=diagnostic.slug, expected=expected)
    assert not failures, (
        f"{diagnostic.provider.slug}/{diagnostic.slug}/{test_case_name}: committed bundle drift:\n"
        + "\n".join(failures)
    )

create_no_drift_test(provider)

Build the standard per-provider integration test for committed-bundle drift.

Returns a pytest function parameterized with one case per diagnostic test case (via :func:climate_ref_core.testing.collect_test_case_params), marked slow and test_cases. Each case configures the provider, resolves the package-local test-case paths, skips when the fetched catalog or committed baseline is missing, and delegates to :func:assert_test_case_no_drift.

Requires ref test-cases fetch --provider <slug> to have been run first.

Usage in a provider's tests/integration/test_diagnostics.py::

from climate_ref_example import provider

from climate_ref.testing import create_no_drift_test

test_run_test_cases = create_no_drift_test(provider)

Parameters:

Name	Type	Description	Default
provider	DiagnosticProvider	The diagnostic provider whose test cases should be exercised.	required

Source code in packages/climate-ref/src/climate_ref/testing.py

def create_no_drift_test(provider: DiagnosticProvider) -> Callable[..., None]:
    """
    Build the standard per-provider integration test for committed-bundle drift.

    Returns a pytest function parameterized with one case per diagnostic test case
    (via :func:`climate_ref_core.testing.collect_test_case_params`),
    marked ``slow`` and ``test_cases``.
    Each case configures the provider,
    resolves the package-local test-case paths,
    skips when the fetched catalog or committed baseline is missing,
    and delegates to :func:`assert_test_case_no_drift`.

    Requires ``ref test-cases fetch --provider <slug>`` to have been run first.

    Usage in a provider's ``tests/integration/test_diagnostics.py``::

        from climate_ref_example import provider

        from climate_ref.testing import create_no_drift_test

        test_run_test_cases = create_no_drift_test(provider)

    Parameters
    ----------
    provider
        The diagnostic provider whose test cases should be exercised.
    """
    import pytest  # noqa: PLC0415

    @pytest.mark.slow
    @pytest.mark.test_cases
    @pytest.mark.parametrize("diagnostic,test_case_name", collect_test_case_params(provider))
    def test_run_test_cases(
        diagnostic: Diagnostic,
        test_case_name: str,
        config: Config,
        tmp_path: Path,
    ) -> None:
        """Execute the test case end-to-end and assert the committed bundle has not drifted."""
        if is_test_case_excluded(diagnostic.provider.slug, diagnostic.slug):
            pytest.skip(
                f"Test-case diagnostic {diagnostic.provider.slug}/{diagnostic.slug} "
                "excluded via REF_TEST_CASES_SKIP"
            )

        diagnostic.provider.configure(config)

        paths = TestCasePaths.from_diagnostic(diagnostic, test_case_name)
        if paths is None:
            pytest.skip(f"No test-data directory for {diagnostic.slug} (not a development checkout)")
        if not paths.catalog.exists():
            pytest.skip(
                f"No catalog file for {diagnostic.slug}/{test_case_name}. "
                f"Run `ref test-cases fetch --provider {provider.slug}` first."
            )
        if not paths.manifest.exists() or not paths.regression.exists():
            pytest.skip(f"No committed baseline for {diagnostic.slug}/{test_case_name}")

        assert_test_case_no_drift(config, diagnostic, test_case_name, paths, tmp_path)

    return test_run_test_cases

fetch_sample_data(force_cleanup=False, symlink=False)

Fetch the sample data for the given version.

The sample data is produced in the Climate-REF/ref-sample-data repository. This repository contains decimated versions of key datasets used by the diagnostics packages. Decimating these data greatly reduces the data volumes needed to run the test-suite.

Parameters:

Name	Type	Description	Default
force_cleanup	bool	If True, remove any existing files	False
symlink	bool	If True, symlink in the data otherwise copy the files The symlink approach is faster, but will fail when running with a non-local executor because the symlinks can't be followed.	False

Source code in packages/climate-ref/src/climate_ref/testing.py

def fetch_sample_data(force_cleanup: bool = False, symlink: bool = False) -> None:
    """
    Fetch the sample data for the given version.

    The sample data is produced in the [Climate-REF/ref-sample-data](https://github.com/Climate-REF/ref-sample-data)
    repository.
    This repository contains decimated versions of key datasets used by the diagnostics packages.
    Decimating these data greatly reduces the data volumes needed to run the test-suite.

    Parameters
    ----------
    force_cleanup
        If True, remove any existing files
    symlink
        If True, symlink in the data otherwise copy the files

        The symlink approach is faster, but will fail when running with a non-local executor
        because the symlinks can't be followed.
    """

    if TEST_DATA_DIR is None:  # pragma: no cover
        logger.warning("Test data directory not found, skipping sample data fetch")
        return

    sample_data_registry = dataset_registry_manager["sample-data"]

    output_dir = TEST_DATA_DIR / "sample-data"
    version_file = output_dir / "version.txt"
    existing_version = None

    if output_dir.exists():  # pragma: no branch
        if version_file.exists():  # pragma: no branch
            with open(version_file) as fh:
                existing_version = fh.read().strip()

        if force_cleanup or existing_version != SAMPLE_DATA_VERSION:  # pragma: no branch
            logger.warning("Removing existing sample data")
            shutil.rmtree(output_dir)

    fetch_all_files(sample_data_registry, "sample", output_dir, symlink)

    # Write out the current sample data version to the copying as complete
    with open(output_dir / "version.txt", "w") as fh:
        fh.write(SAMPLE_DATA_VERSION)