nimrod monkey patch

improver/utilities/load.py

@@ -30,6 +30,7 @@
 # POSSIBILITY OF SUCH DAMAGE.
 """Module for loading cubes."""
 
+import contextlib
 import glob
 
 import iris
@@ -38,6 +39,16 @@
     enforce_coordinate_ordering, merge_cubes)
 
 
+@contextlib.contextmanager
+def monkeypatched(object, name, patch):
+    """ Temporarily monkeypatches an object. """
+
+    pre_patched_value = getattr(object, name)
+    setattr(object, name, patch)
+    yield object
+    setattr(object, name, pre_patched_value)
+
+
 def load_cube(filepath, constraints=None, no_lazy_load=False,
               allow_none=False):
     """Load the filepath provided using Iris into a cube.
@@ -65,6 +76,21 @@ def load_cube(filepath, constraints=None, no_lazy_load=False,
             Cube that has been loaded from the input filepath given the
             constraints provided.
     """
+    # FIXME: monkey patched nimrod loading in iris, so it works for radar files
+    try:
+        iris.fileformats.nimrod_load_rules.DEFAULT_UNITS
+    except AttributeError:
+        try:
+            from iris_nimrod_patch import nimrod, nimrod_load_rules
+        except ImportError:
+            pass
+        else:
+            for attr in ['general_header_int16s', 'general_header_float32s',
+                         'data_header_int16s', 'data_header_float32s']:
+                setattr(iris.fileformats.nimrod, attr, getattr(nimrod, attr))
+    else:
+        raise RuntimeError('FIXME: nimrod monkey patch is no longer needed')
+
     if filepath is None and allow_none:
         return None
     # Remove metadata prefix cube if present
@@ -73,12 +99,14 @@ def load_cube(filepath, constraints=None, no_lazy_load=False,
 
     # Load each file individually to avoid partial merging (not used
     # iris.load_raw() due to issues with time representation)
-    if isinstance(filepath, str):
-        cubes = iris.load(filepath, constraints=constraints)
-    else:
-        cubes = iris.cube.CubeList([])
-        for item in filepath:
-            cubes.extend(iris.load(item, constraints=constraints))
+    with monkeypatched(iris.fileformats, 'nimrod_load_rules',
+                       nimrod_load_rules):
+        if isinstance(filepath, str):
+            cubes = iris.load(filepath, constraints=constraints)
+        else:
+            cubes = iris.cube.CubeList([])
+            for item in filepath:
+                cubes.extend(iris.load(item, constraints=constraints))
 
     # Merge loaded cubes
     if not cubes:

improver_tests/acceptance/acceptance.py

@@ -158,6 +158,13 @@ def statsmodels_available():
     return False
 
 
+def iris_nimrod_patch_available():
+    """True if iris_nimrod_patch library is importable"""
+    if importlib.util.find_spec('iris_nimrod_patch'):
+        return True
+    return False
+
+
 def compare(output_path, kgo_path, recreate=True,
             atol=DEFAULT_TOLERANCE, rtol=DEFAULT_TOLERANCE, exclude_vars=None):
     """
@@ -215,3 +222,9 @@ def message_recorder(exception_message):
 # pylint: disable=invalid-name
 skip_if_no_statsmodels = pytest.mark.skipif(
     not statsmodels_available(), reason="statsmodels library is not available")
+
+# Pytest decorator to skip tests if iris_nimrod_patch is not available
+# pylint: disable=invalid-name
+skip_if_no_iris_nimrod_patch = pytest.mark.skipif(
+    not iris_nimrod_patch_available(),
+    reason="iris_nimrod_patch library is not available")

improver_tests/acceptance/test_standardise.py

@@ -223,3 +223,29 @@ def test_stage_v110_basic(tmp_path):
             "--output", output_path]
     run_cli(args)
     acc.compare(output_path, kgo_path)
+
+
+@acc.skip_if_no_iris_nimrod_patch
+def test_nimrod_radarrate_basic(tmp_path):
+    """Test updating a file with Nimrod-format Radarnet data"""
+    kgo_dir = acc.kgo_root() / "standardise/radarnet"
+    kgo_path = kgo_dir / "kgo_preciprate.nc"
+    input_path = kgo_dir / "input_preciprate.nimrod"
+    output_path = tmp_path / "output.nc"
+    args = [input_path,
+            "--output", output_path]
+    run_cli(args)
+    acc.compare(output_path, kgo_path)
+
+
+@acc.skip_if_no_iris_nimrod_patch
+def test_nimrod_radarcoverage_basic(tmp_path):
+    """Test updating a file with Nimrod-format Radarnet data"""
+    kgo_dir = acc.kgo_root() / "standardise/radarnet"
+    kgo_path = kgo_dir / "kgo_coverage.nc"
+    input_path = kgo_dir / "input_coverage.nimrod"
+    output_path = tmp_path / "output.nc"
+    args = [input_path,
+            "--output", output_path]
+    run_cli(args)
+    acc.compare(output_path, kgo_path)