fix(dfn): restore dfn module and tests

Author: wpbonelli

autotest/test_dfn.py

@@ -0,0 +1,62 @@
+from pathlib import Path
+
+import pytest
+
+from modflow_devtools.dfn import Dfn, get_dfns
+from modflow_devtools.dfn2toml import convert
+from modflow_devtools.markers import requires_pkg
+
+PROJ_ROOT = Path(__file__).parents[1]
+DFN_DIR = PROJ_ROOT / "autotest" / "temp" / "dfn"
+TOML_DIR = DFN_DIR / "toml"
+VERSIONS = {1: DFN_DIR, 2: TOML_DIR}
+MF6_OWNER = "MODFLOW-ORG"
+MF6_REPO = "modflow6"
+MF6_REF = "develop"
+
+
+def pytest_generate_tests(metafunc):
+    if "dfn_name" in metafunc.fixturenames:
+        if not any(DFN_DIR.glob("*.dfn")):
+            get_dfns(MF6_OWNER, MF6_REPO, MF6_REF, DFN_DIR, verbose=True)
+        dfn_names = [
+            dfn.stem for dfn in DFN_DIR.glob("*.dfn") if dfn.stem not in ["common", "flopy"]
+        ]
+        metafunc.parametrize("dfn_name", dfn_names, ids=dfn_names)
+
+    if "toml_name" in metafunc.fixturenames:
+        # Only convert if TOML files don't exist yet (avoid repeated conversions)
+        dfn_paths = [p for p in DFN_DIR.glob("*.dfn") if p.stem not in ["common", "flopy"]]
+        if not TOML_DIR.exists() or not all(
+            (TOML_DIR / f"{dfn.stem}.toml").is_file() for dfn in dfn_paths
+        ):
+            convert(DFN_DIR, TOML_DIR)
+        # Verify all expected TOML files were created
+        assert all((TOML_DIR / f"{dfn.stem}.toml").is_file() for dfn in dfn_paths)
+        toml_names = [toml.stem for toml in TOML_DIR.glob("*.toml")]
+        metafunc.parametrize("toml_name", toml_names, ids=toml_names)
+
+
+@requires_pkg("boltons")
+def test_load_v1(dfn_name):
+    with (
+        (DFN_DIR / "common.dfn").open() as common_file,
+        (DFN_DIR / f"{dfn_name}.dfn").open() as dfn_file,
+    ):
+        common, _ = Dfn._load_v1_flat(common_file)
+        dfn = Dfn.load(dfn_file, name=dfn_name, common=common)
+        assert any(dfn)
+
+
+@requires_pkg("boltons")
+def test_load_v2(toml_name):
+    with (TOML_DIR / f"{toml_name}.toml").open(mode="rb") as toml_file:
+        toml = Dfn.load(toml_file, name=toml_name, version=2)
+        assert any(toml)
+
+
+@requires_pkg("boltons")
+@pytest.mark.parametrize("version", list(VERSIONS.keys()))
+def test_load_all(version):
+    dfns = Dfn.load_all(VERSIONS[version], version=version)
+    assert any(dfns)