unit test suite and CI

.github/workflows/tests.yml

@@ -0,0 +1,53 @@
+name: Tests
+
+# Runs on every PR and on pushes to main. 
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  unit-tests:
+    name: Unit tests (Python ${{ matrix.python-version }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false  # run both Python versions even if one fails, so we see both
+      matrix:
+        # 3.11+ only: the package uses `match` and `int | float` unions (3.10+)
+        # and requires-python is >=3.11. Older versions fail on import.
+        python-version: ["3.11", "3.12"]
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: "pip"
+          cache-dependency-path: package/pyproject.toml
+
+      # The workflow lives at repo root, but the package is in ./package,
+      # so every step below runs from there (matches local dev from package/).
+      - name: Install package with test dependencies
+        working-directory: ./package
+        run: |
+          python -m pip install --upgrade pip
+          pip install -e ".[test]"
+
+      # --check / --check-only report only; they never edit. CI fails if code
+      # was committed unformatted. Mirrors the local pre-commit checks.
+      - name: Check formatting (Black)
+        working-directory: ./package
+        run: black --check tests/
+
+      - name: Check import order (isort)
+        working-directory: ./package
+        run: isort --check-only tests/
+
+      # -m "not integration": runs everything except tests marked @pytest.mark.integration.
+      # (no integration tests yet) 
+      - name: Run unit tests
+        working-directory: ./package
+        run: pytest -v -m "not integration"

package/pyproject.toml

@@ -5,7 +5,7 @@ description = "A Python package for generating methods sections in for ASL param
 authors = [{ name="Ibrahim Abdelazim", email="ibrahim.abdelazim@fau.de" }]
 license = "MIT"
 readme = "README.md"
-requires-python = ">=3.7"
+requires-python = ">=3.11"
 dependencies = [
     "PyYAML~=6.0.2",
     "numpy~=2.2.6",
@@ -26,4 +26,37 @@ include-package-data = true
 where = ["src"]
 
 [tool.setuptools.package-data]
-"pyaslreport" = ["*.yaml", "**/*.yaml"]
+"pyaslreport" = ["*.yaml", "**/*.yaml"]
+
+[project.optional-dependencies]
+test = [
+    "pytest>=7.0",
+    "pytest-cov>=4.0",
+    "black==26.5.1",
+    "isort==8.0.1",
+]
+
+[tool.pytest.ini_options]
+minversion = "7.0"
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+python_classes = ["Test*"]
+python_functions = ["test_*"]
+addopts = [
+    "-ra",
+    "--strict-markers",
+    "--strict-config",
+]
+markers = [
+    "integration: integration tests requiring file fixtures (deselect with '-m \"not integration\"')",
+    "slow: tests that take noticeably longer to run",
+]
+
+[tool.black]
+line-length = 88
+target-version = ["py311"]
+
+[tool.isort]
+profile = "black"
+line_length = 88
+known_first_party = ["pyaslreport"]

package/src/pyaslreport/modalities/asl/utils.py

@@ -48,7 +48,7 @@ def compare_params(params_asl, params_m0, asl_filename, m0_filename):
                         f"Discrepancy in '{param}' for ASL file '{asl_filename}' and M0 file '{m0_filename}': "
                         f"ASL value = {asl_value}, M0 value = {m0_value}")
             elif validation_type == "floatOrArray":
-                if isinstance(asl_value, float) and isinstance(m0_value, float):
+                if isinstance(asl_value, (int, float)) and isinstance(m0_value, (int, float)):
                     difference = abs(asl_value - m0_value)
                     difference_formatted = f"{difference:.2f}"
                     if difference > error_variation:

package/tests/conftest.py

@@ -0,0 +1,198 @@
+"""Shared fixtures and pytest configuration for pyaslreport tests.
+
+Fixtures provided:
+    minimal_nifti_path: Path to a tiny on-disk NIfTI file (auto-deleted after test).
+    make_context: Factory for building ProcessingContext with sensible defaults.
+    make_processor: Factory for building ASLProcessor without triggering validation.
+    examples_dir: Path to the integration examples directory (pytest-configurable).
+    minimal_asl_json: In-memory dict representing a minimal valid ASL JSON.
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+from typing import Any, Callable
+
+import nibabel as nib
+import numpy as np
+import pytest
+
+from pyaslreport.modalities.asl.processor import ASLProcessor, ProcessingContext
+
+
+# ---------------------------------------------------------------------------
+# CLI option for integration test directory
+# ---------------------------------------------------------------------------
+def pytest_addoption(parser: pytest.Parser) -> None:
+    """Register the --examples-dir CLI option for the integration runner.
+
+    Args:
+        parser: The pytest CLI parser, supplied by pytest at collection time.
+
+    Notes:
+        Local usage:  pytest --examples-dir=/path/to/examples
+        CI usage:     omit the flag; defaults to the committed set in
+                      tests/integration/examples.
+    """
+    parser.addoption(
+        "--examples-dir",
+        action="store",
+        default=None,
+        help="Path to integration examples dir; falls back to the committed CI set.",
+    )
+
+
+# ---------------------------------------------------------------------------
+# File-based fixtures
+# ---------------------------------------------------------------------------
+@pytest.fixture
+def minimal_nifti_path(tmp_path: Path) -> Path:
+    """Create a tiny valid NIfTI file at tmp_path/asl.nii.gz.
+
+    Args:
+        tmp_path: Pytest-provided per-test temporary directory.
+
+    Returns:
+        Path to the written NIfTI file with shape (4, 4, 20, 2). The third
+        axis matches a sensible default for ProcessingContext.nifti_slice_number
+        so most tests do not need a custom shape.
+    """
+    data = np.zeros((4, 4, 20, 2), dtype=np.float32)
+    img = nib.Nifti1Image(data, affine=np.eye(4))
+
+    path = tmp_path / "asl.nii.gz"
+    nib.save(img, str(path))
+
+    return path
+
+
+@pytest.fixture
+def examples_dir(request: pytest.FixtureRequest) -> Path:
+    """Return the path to the integration examples directory.
+
+    Args:
+        request: Pytest fixture request, used to read the --examples-dir flag.
+
+    Returns:
+        Resolved path to an existing examples directory.
+
+    Raises:
+        pytest.skip.Exception: If the resolved path does not exist. Resolution
+            order is (1) the --examples-dir CLI flag, then (2) the committed
+            tests/integration/examples directory beside this conftest.
+    """
+    cli_value = request.config.getoption("--examples-dir")
+
+    if cli_value:
+        path = Path(cli_value).expanduser().resolve()
+    else:
+        path = Path(__file__).parent / "integration" / "examples"
+
+    if not path.is_dir():
+        pytest.skip(f"Examples directory not found: {path}")
+
+    return path
+
+
+# ---------------------------------------------------------------------------
+# Factory fixtures
+# ---------------------------------------------------------------------------
+@pytest.fixture
+def make_context() -> Callable[..., ProcessingContext]:
+    """Return a factory for building ProcessingContext with sensible defaults.
+
+    Returns:
+        A callable that accepts keyword overrides and returns a fully-formed
+        ProcessingContext. All ten required fields receive defaults; pass
+        keyword arguments to override any of them.
+
+    Example:
+        >>> def test_something(make_context):
+        ...     ctx = make_context(m0_type="Separate", errors=["something"])
+        ...     assert ctx.m0_type == "Separate"
+    """
+
+    def _make(**overrides: Any) -> ProcessingContext:
+        defaults: dict[str, Any] = {
+            "asl_json_data": [],
+            "m0_prep_times_collection": [],
+            "errors": [],
+            "warnings": [],
+            "all_absent": True,
+            "bs_all_off": True,
+            "m0_type": None,
+            "global_pattern": None,
+            "total_acquired_pairs": None,
+            "nifti_slice_number": 20,
+        }
+
+        defaults.update(overrides)
+
+        return ProcessingContext(**defaults)
+
+    return _make
+
+
+@pytest.fixture
+def make_processor(minimal_nifti_path: Path) -> Callable[..., ASLProcessor]:
+    """Return a factory for building ASLProcessor without input validation.
+
+    Args:
+        minimal_nifti_path: Auto-injected fixture providing a real on-disk
+            NIfTI file. The factory uses it as the default nifti_file unless
+            the caller overrides it.
+
+    Returns:
+        A callable that accepts keyword overrides and returns an ASLProcessor.
+        Useful for testing private methods like _group_files in isolation,
+        because BaseProcessor.__init__ stores self.data without validating.
+
+    Example:
+        >>> def test_grouping(make_processor):
+        ...     proc = make_processor(files=["/path/to/asl.json"])
+        ...     groups = proc._group_files("nifti")
+    """
+
+    def _make(**overrides: Any) -> ASLProcessor:
+        defaults: dict[str, Any] = {
+            "modality": "asl",
+            "files": [],
+            "dcm_files": [],
+            "nifti_file": str(minimal_nifti_path),
+        }
+
+        defaults.update(overrides)
+
+        return ASLProcessor(defaults)
+
+    return _make
+
+
+# ---------------------------------------------------------------------------
+# Data fixtures (in-memory JSON dicts)
+# ---------------------------------------------------------------------------
+@pytest.fixture
+def minimal_asl_json() -> dict[str, Any]:
+    """Return a minimal ASL JSON with all major-error fields valid.
+
+    Returns:
+        Dictionary intended as a starting point for normalization and
+        validation tests. Spread it into a new dict and override individual
+        fields to introduce specific missing or invalid values.
+    """
+    return {
+        "ArterialSpinLabelingType": "PCASL",
+        "MRAcquisitionType": "3D",
+        "PulseSequenceType": "GRASE",
+        "M0Type": "Separate",
+        "BackgroundSuppression": False,
+        "PostLabelingDelay": 1.8,
+        "LabelingDuration": 1.8,
+        "EchoTime": 0.012,
+        "RepetitionTimePreparation": 4.0,
+        "FlipAngle": 90,
+        "MagneticFieldStrength": 3,
+        "Manufacturer": "Siemens",
+        "ManufacturersModelName": "TrioTim",
+        "AcquisitionVoxelSize": [3, 3, 4],
+    }