Move ugrid loading support code from iris.mesh to iris.netcdf, and it…

…s tests likewise

lib/iris/fileformats/netcdf/loader.py

@@ -584,7 +584,8 @@ def load_cubes(file_sources, callback=None, constraints=None):
     # Deferred import to avoid circular imports.
     from iris.io import run_callback
     from iris.mesh.cf import CFUGridReader
-    from iris.mesh.load import (
+
+    from .ugrid_load import (
         _build_mesh_coords,
         _meshes_from_cf,
     )

lib/iris/mesh/load.py → lib/iris/fileformats/netcdf/ugrid_load.py

@@ -8,8 +8,6 @@
 Extensions to Iris' NetCDF loading to allow the construction of
 :class:`~iris.mesh.MeshXY` from UGRID data in the file.
 
-Eventual destination: :mod:`iris.fileformats.netcdf`.
-
 .. seealso::
 
     The UGRID Conventions,
@@ -21,20 +19,20 @@
 from pathlib import Path
 import warnings
 
-from ..config import get_logger
-from ..coords import AuxCoord
-from ..fileformats._nc_load_rules.helpers import get_attr_units, get_names
-from ..fileformats.netcdf import loader as nc_loader
-from ..io import decode_uri, expand_filespecs
-from ..util import guess_coord_axis
-from ..warnings import IrisCfWarning, IrisDefaultingWarning, IrisIgnoringWarning
-from .cf import (
+from iris.config import get_logger
+from iris.coords import AuxCoord
+from iris.fileformats._nc_load_rules.helpers import get_attr_units, get_names
+from iris.fileformats.netcdf import loader as nc_loader
+from iris.io import decode_uri, expand_filespecs
+from iris.mesh import Connectivity, MeshXY
+from iris.mesh.cf import (
     CFUGridAuxiliaryCoordinateVariable,
     CFUGridConnectivityVariable,
     CFUGridMeshVariable,
     CFUGridReader,
 )
-from .components import Connectivity, MeshXY
+from iris.util import guess_coord_axis
+from iris.warnings import IrisCfWarning, IrisDefaultingWarning, IrisIgnoringWarning
 
 # Configure the logger.
 logger = get_logger(__name__, propagate=True, handler=False)
@@ -124,7 +122,7 @@ def load_meshes(uris, var_name=None):
     # No constraints or callbacks supported - these assume they are operating
     #  on a Cube.
 
-    from ..fileformats import FORMAT_AGENT
+    from iris.fileformats import FORMAT_AGENT
 
     if isinstance(uris, str):
         uris = [uris]

lib/iris/mesh/__init__.py

@@ -9,10 +9,10 @@
 """
 
 from iris.fileformats.netcdf.saver import save_mesh
+from iris.fileformats.netcdf.ugrid_load import load_mesh, load_meshes
 
 from ..config import get_logger
 from .components import Connectivity, MeshCoord, MeshXY
-from .load import load_mesh, load_meshes
 from .utils import recombine_submeshes
 
 __all__ = [

lib/iris/tests/integration/mesh/test_ugrid_load.py → lib/iris/tests/integration/netcdf/test_ugrid_load.py

@@ -2,13 +2,7 @@
 #
 # This file is part of Iris and is released under the BSD license.
 # See LICENSE in the root of the repository for full licensing details.
-"""Integration tests for NetCDF-UGRID file loading.
-
-todo: fold these tests into netcdf tests when iris.mesh is folded into
- standard behaviour.
-TODO: complete iris.mesh replacement
-
-"""
+"""Integration tests for NetCDF-UGRID file loading."""
 
 # Import iris.tests first so that some things can be initialised before
 # importing anything else.
@@ -19,8 +13,7 @@
 import pytest
 
 from iris import Constraint, load
-from iris.mesh import MeshXY
-from iris.mesh.load import load_mesh, load_meshes
+from iris.mesh import MeshXY, load_mesh, load_meshes
 from iris.tests.stock.netcdf import (
     _file_from_cdl_template as create_file_from_cdl_template,
 )

lib/iris/tests/unit/mesh/load/__init__.py → lib/iris/tests/unit/fileformats/netcdf/loader/ugrid_load/__init__.py

@@ -2,4 +2,4 @@
 #
 # This file is part of Iris and is released under the BSD license.
 # See LICENSE in the root of the repository for full licensing details.
-"""Unit tests for the :mod:`iris.mesh.load` package."""
+"""Unit tests for the :mod:`iris.fileformats.netcdf.ugrid_load` package."""

lib/iris/tests/unit/mesh/load/test_load_mesh.py → lib/iris/tests/unit/fileformats/netcdf/loader/ugrid_load/test_load_mesh.py

@@ -8,14 +8,15 @@
 # importing anything else.
 import iris.tests as tests  # isort:skip
 
-from iris.mesh.load import load_mesh
+from iris.mesh import load_mesh
 
 
 class Tests(tests.IrisTest):
     # All 'real' tests have been done for load_meshes(). Here we just check
     #  that load_mesh() works with load_meshes() correctly, using mocking.
     def setUp(self):
-        self.load_meshes_mock = self.patch("iris.mesh.load.load_meshes")
+        tgt = "iris.fileformats.netcdf.ugrid_load.load_meshes"
+        self.load_meshes_mock = self.patch(tgt)
         # The expected return from load_meshes - a dict of files, each with
         #  a list of meshes.
         self.load_meshes_mock.return_value = {"file": ["mesh"]}

lib/iris/tests/unit/mesh/load/test_load_meshes.py → lib/iris/tests/unit/fileformats/netcdf/loader/ugrid_load/test_load_meshes.py

@@ -13,7 +13,8 @@
 import tempfile
 from uuid import uuid4
 
-from iris.mesh.load import load_meshes, logger
+from iris.fileformats.netcdf.ugrid_load import logger
+from iris.mesh import load_meshes
 from iris.tests.stock.netcdf import ncgen_from_cdl