From 249bdb63ed2ad9b30cd21bcdc58746bc12b7c218 Mon Sep 17 00:00:00 2001
From: Patrick Peglar <patrick.peglar@metoffice.gov.uk>
Date: Sun, 30 Jul 2023 23:15:10 +0100
Subject: [PATCH 1/2] Make roundtrip checking more precise + improve some tests
 accordingly.

---
 .../integration/test_netcdf__loadsaveattrs.py | 32 ++++++++++---------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py b/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
index 77eb3e5324..e432b238b5 100644
--- a/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
+++ b/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
@@ -39,6 +39,7 @@
 
 # A list of "global-style" attribute names : those which should be global attributes by
 # default (i.e. file- or group-level, *not* attached to a variable).
+
 _GLOBAL_TEST_ATTRS = set(iris.fileformats.netcdf.saver._CF_GLOBAL_ATTRS)
 # Remove this one, which has peculiar behaviour + is tested separately
 # N.B. this is not the same as 'Conventions', but is caught in the crossfire when that
@@ -263,16 +264,15 @@ def check_roundtrip_results(
         else:
             assert self.attrname in ds.ncattrs()
             assert ds.getncattr(self.attrname) == global_attr_value
-        if var_attr_vals:
-            var_attr_vals = self._default_vars_and_attrvalues(var_attr_vals)
-            for var_name, value in var_attr_vals.items():
-                assert var_name in ds.variables
-                v = ds.variables[var_name]
-                if value is None:
-                    assert self.attrname not in v.ncattrs()
-                else:
-                    assert self.attrname in v.ncattrs()
-                    assert v.getncattr(self.attrname) == value
+        var_attr_vals = self._default_vars_and_attrvalues(var_attr_vals)
+        for var_name, value in var_attr_vals.items():
+            assert var_name in ds.variables
+            v = ds.variables[var_name]
+            if value is None:
+                assert self.attrname not in v.ncattrs()
+            else:
+                assert self.attrname in v.ncattrs()
+                assert v.getncattr(self.attrname) == value
 
     #######################################################
     # Tests on "user-style" attributes.
@@ -302,7 +302,7 @@ def test_02_userstyle_single_local(self):
         # It results in a "promoted" global attribute.
         self.create_roundtrip_testcase(
             attr_name="myname",  # A generic "user" attribute with no special handling
-            vars_values_file1={"myvar": "single-value"},
+            vars_values_file1="single-value",
         )
         self.check_roundtrip_results(
             global_attr_value="single-value",  # local values eclipse the global ones
@@ -545,10 +545,12 @@ def test_16_localstyle(self, local_attr, origin_style):
                 attr_name=local_attr, vars_values_file1=attrval
             )
 
-        if local_attr in iris.fileformats.netcdf.saver._CF_DATA_ATTRS:
-            # These ones are simply discarded on loading.
-            # By experiment, this overlap between _CF_ATTRS and _CF_DATA_ATTRS
-            # currently contains only 'missing_value' and 'standard_error_multiplier'.
+        if (
+                local_attr in ('missing_value', 'standard_error_multiplier')
+                and origin_style == "input_local"
+        ):
+            # These ones are actually discarded by roundtrip.
+            # Not clear why, but for now this captures the facts.
             expect_global = None
             expect_var = None
         else:

From f85975472d09ed828981068f3a653b57dbe86b7d Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 30 Jul 2023 23:11:46 +0000
Subject: [PATCH 2/2] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 lib/iris/tests/integration/test_netcdf__loadsaveattrs.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py b/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
index e432b238b5..14d7f2fadf 100644
--- a/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
+++ b/lib/iris/tests/integration/test_netcdf__loadsaveattrs.py
@@ -546,8 +546,8 @@ def test_16_localstyle(self, local_attr, origin_style):
             )
 
         if (
-                local_attr in ('missing_value', 'standard_error_multiplier')
-                and origin_style == "input_local"
+            local_attr in ("missing_value", "standard_error_multiplier")
+            and origin_style == "input_local"
         ):
             # These ones are actually discarded by roundtrip.
             # Not clear why, but for now this captures the facts.