Various testing fixes

.cirrus.yml

@@ -96,13 +96,23 @@ linux_task_template: &LINUX_TASK_TEMPLATE
 
 tests_task:
   matrix:
-    env:
-      PY_VER: 3.6
-    env:
-      PY_VER: 3.7
-    # env:
-    #   PY_VER: 3.8
-  name: "${CIRRUS_OS}: py${PY_VER} tests"
+    - name: "${CIRRUS_OS} tests: iris=repo-main python=3.7"
+      env:
+        PY_VER: 3.7
+        IRIS_SOURCE: "source"
+    - name: "${CIRRUS_OS} tests: iris=repo-main python=3.8"
+      env:
+        PY_VER: 3.8
+        IRIS_SOURCE: "source"
+    - name: "${CIRRUS_OS} tests: iris=conda-release python=3.7"
+      env:
+        PY_VER: 3.7
+        IRIS_SOURCE: "conda-forge"
+    - name: "${CIRRUS_OS} tests: iris=conda-release python=3.8"
+      env:
+        PY_VER: 3.8
+        IRIS_SOURCE: "conda-forge"
+
   << : *LINUX_TASK_TEMPLATE
   tests_script:
     - export CONDA_OVERRIDE_LINUX="$(uname -r | cut -d'+' -f1)"

iris_grib/__init__.py

@@ -25,7 +25,6 @@
 from iris._lazy_data import as_lazy_data
 import iris.coord_systems as coord_systems
 from iris.exceptions import TranslationError, NotYetImplementedError
-from iris.util import _array_slice_ifempty
 
 from . import grib_phenom_translation as gptx
 from . import _save_rules
@@ -98,17 +97,13 @@ def ndim(self):
         return len(self.shape)
 
     def __getitem__(self, keys):
-        # Avoid fetching file data just to return an 'empty' result.
-        # Needed because of how dask.array.from_array behaves since Dask v2.0.
-        result = _array_slice_ifempty(keys, self.shape, self.dtype)
-        if result is None:
-            with open(self.path, 'rb') as grib_fh:
-                grib_fh.seek(self.offset)
-                grib_message = gribapi.grib_new_from_file(grib_fh)
-                data = _message_values(grib_message, self.shape)
-                gribapi.grib_release(grib_message)
-
-            result = data.__getitem__(keys)
+        with open(self.path, 'rb') as grib_fh:
+            grib_fh.seek(self.offset)
+            grib_message = gribapi.grib_new_from_file(grib_fh)
+            data = _message_values(grib_message, self.shape)
+            gribapi.grib_release(grib_message)
+
+        result = data.__getitem__(keys)
 
         return result
 

iris_grib/message.py

@@ -12,7 +12,6 @@
 import re
 
 import gribapi
-from iris_grib import _array_slice_ifempty
 import numpy as np
 import numpy.ma as ma
 
@@ -233,32 +232,28 @@ def __getitem__(self, keys):
         # NB. Currently assumes that the validity of this interpretation
         # is checked before this proxy is created.
 
-        # Avoid fetching file data just to return an 'empty' result.
-        # Needed because of how dask.array.from_array behaves since Dask v2.0.
-        result = _array_slice_ifempty(keys, self.shape, self.dtype)
-        if result is None:
-            message = self.recreate_raw()
-            sections = message.sections
-            bitmap_section = sections[6]
-            bitmap = self._bitmap(bitmap_section)
-            data = sections[7]['codedValues']
-
-            if bitmap is not None:
-                # Note that bitmap and data are both 1D arrays at this point.
-                if np.count_nonzero(bitmap) == data.shape[0]:
-                    # Only the non-masked values are included in codedValues.
-                    _data = np.empty(shape=bitmap.shape)
-                    _data[bitmap.astype(bool)] = data
-                    # `ma.masked_array` masks where input = 1, the opposite of
-                    # the behaviour specified by the GRIB spec.
-                    data = ma.masked_array(_data, mask=np.logical_not(bitmap),
-                                           fill_value=np.nan)
-                else:
-                    msg = 'Shapes of data and bitmap do not match.'
-                    raise TranslationError(msg)
-
-            data = data.reshape(self.shape)
-            result = data.__getitem__(keys)
+        message = self.recreate_raw()
+        sections = message.sections
+        bitmap_section = sections[6]
+        bitmap = self._bitmap(bitmap_section)
+        data = sections[7]['codedValues']
+
+        if bitmap is not None:
+            # Note that bitmap and data are both 1D arrays at this point.
+            if np.count_nonzero(bitmap) == data.shape[0]:
+                # Only the non-masked values are included in codedValues.
+                _data = np.empty(shape=bitmap.shape)
+                _data[bitmap.astype(bool)] = data
+                # `ma.masked_array` masks where input = 1, the opposite of
+                # the behaviour specified by the GRIB spec.
+                data = ma.masked_array(_data, mask=np.logical_not(bitmap),
+                                       fill_value=np.nan)
+            else:
+                msg = 'Shapes of data and bitmap do not match.'
+                raise TranslationError(msg)
+
+        data = data.reshape(self.shape)
+        result = data.__getitem__(keys)
 
         return result
 

iris_grib/tests/unit/message/test__DataProxy.py

@@ -43,31 +43,5 @@ def test_bitmap__invalid_indicator(self):
             data_proxy._bitmap(section_6)
 
 
-class Test_emptyfetch(tests.IrisGribTest):
-    # See :
-    #   iris.tests.unit.fileformats.pp.test_PPDataProxy.Test__getitem__slicing
-    # In this case, test *only* the no-data-read effect, not the method which
-    # is part of Iris.
-    def test_empty_slice(self):
-        # Check behaviour of the getitem call with an 'empty' slicing.
-        # This is necessary because, since Dask 2.0, the "from_array" function
-        # takes a zero-length slice of its array argument, to capture array
-        # metadata, and in those cases we want to avoid file access.
-        test_dtype = np.dtype(np.float32)
-        mock_datafetch = mock.MagicMock()
-        proxy = _DataProxy(shape=(3, 4),
-                           dtype=np.dtype(np.float32),
-                           recreate_raw=mock_datafetch)
-
-        # Test the special no-data indexing operation.
-        result = proxy[0:0, 0:0]
-
-        # Check the behaviour and results were as expected.
-        self.assertEqual(mock_datafetch.call_count, 0)
-        self.assertIsInstance(result, np.ndarray)
-        self.assertEqual(result.dtype, test_dtype)
-        self.assertEqual(result.shape, (0, 0))
-
-
 if __name__ == '__main__':
     tests.main()

noxfile.py

@@ -25,7 +25,7 @@
 PACKAGE = str("iris_grib")
 
 #: Cirrus-CI environment variable hook.
-PY_VER = os.environ.get("PY_VER", ["3.6", "3.7"])
+PY_VER = os.environ.get("PY_VER", ["3.7", "3.8"])
 IRIS_SOURCE = os.environ.get("IRIS_SOURCE", ['source', 'conda-forge'])
 
 #: Default cartopy cache directory.
@@ -284,14 +284,14 @@ def tests(session, iris):
         iris_dir = f"{session.create_tmp()}/iris"
 
         if os.path.exists(iris_dir):
-            # cached.  update by pulling from origin/master
+            # cached.  update by pulling from origin/main
             session.run(
                 "git",
                 "-C",
                 iris_dir,
                 "pull",
                 "origin",
-                "master",
+                "main",
                 external=True  # use git from host environment
             )
         else:
@@ -330,8 +330,6 @@ def tests(session, iris):
         "-m",
         "iris_grib.tests.runner",
         "--default-tests",
-        "--unit-tests",
-        "--integration-tests",
     )
 
 
@@ -385,4 +383,4 @@ def linkcheck(session):
         "make",
         "linkcheck",
         external=True,
-    )
+    )