Prevent platforms and groups sharing names

.coveragerc

@@ -34,7 +34,6 @@ omit=
 parallel = True
 plugins=
 source=
-    ./bin
     ./cylc
 timid = False
 

CHANGES.md

@@ -127,6 +127,10 @@ Fix ``cylc stop --kill`` which was not actually killing task jobs.
 [#4338](https://github.com/cylc/cylc-flow/pull/4338) - Cylc install -C option
 now works with relative paths.
 
+[#4445](https://github.com/cylc/cylc-flow/pull/4445) - Cylc will prevent you
+using the same name for a platform and a platform group. Which one it should
+pick is ambiguous, and is a setup error.
+
 -------------------------------------------------------------------------------
 ## __cylc-8.0b2 (<span actions:bind='release-date'>Released 2021-07-28</span>)__
 

cylc/flow/cfgspec/globalcfg.py

@@ -22,6 +22,7 @@
 
 from cylc.flow import LOG
 from cylc.flow import __version__ as CYLC_VERSION
+from cylc.flow.exceptions import GlobalConfigError
 from cylc.flow.hostuserutil import get_user_home
 from cylc.flow.network.client_factory import CommsMeth
 from cylc.flow.parsec.config import (
@@ -1141,6 +1142,7 @@ def load(self):
                     raise
 
         self._set_default_editors()
+        self._no_platform_group_name_overlap()
 
     def _set_default_editors(self):
         # default to $[G]EDITOR unless an editor is defined in the config
@@ -1150,3 +1152,21 @@ def _set_default_editors(self):
             cfg['editors']['terminal'] = os.environ.get('EDITOR') or 'vi'
         if not cfg['editors']['gui']:
             cfg['editors']['gui'] = os.environ.get('GEDITOR') or 'gvim -fg'
+
+    def _no_platform_group_name_overlap(self):
+        if (
+            'platforms' in self.sparse and
+            'platform groups' in self.sparse
+        ):
+            names_in_platforms_and_groups = set(
+                self.sparse['platforms'].keys()).intersection(
+                    set(self.sparse['platform groups'].keys()))
+
+            if names_in_platforms_and_groups:
+                msg = (
+                    'Platforms and platform groups must not share names. '
+                    'The following are in both sets:'
+                )
+                for name in names_in_platforms_and_groups:
+                    msg += f'\n * {name}'
+                raise GlobalConfigError(msg)

cylc/flow/exceptions.py

@@ -67,6 +67,10 @@ class WorkflowConfigError(CylcConfigError):
     """Exception for configuration errors in a Cylc workflow configuration."""
 
 
+class GlobalConfigError(CylcConfigError):
+    """Exception for configuration errors in a Cylc global configuration."""
+
+
 class GraphParseError(WorkflowConfigError):
     """Exception for errors in Cylc workflow graphing."""
 

tests/functional/cylc-get-config/07-failif-item-in-platforms-and-groups.t

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#-------------------------------------------------------------------------------
+# Test that Platforms and Platform Groups return an error listing items
+# defined in both.
+# Not having additional tests for cases with no overlap or platforms only
+# becuase other tests will fail.
+# Not testing for platform groups only because the really should never happen.
+
+. "$(dirname "$0")/test_header"
+#-------------------------------------------------------------------------------
+set_test_number 4
+
+create_test_global_config '' '''
+[platforms]
+    [[Thomas]]
+    [[Percy]]
+    [[Edward]]
+    [[Skarloey]]
+[platform groups]
+    [[Thomas]]
+    [[Percy]]
+    [[Gordon]]
+    [[Rhenas]]
+'''
+
+run_fail "${TEST_NAME_BASE}" cylc config
+grep_ok "GlobalConfigError" "${TEST_NAME_BASE}.stderr"
+grep_ok "\* Thomas" "${TEST_NAME_BASE}.stderr"
+grep_ok "\* Percy" "${TEST_NAME_BASE}.stderr"
+
+
+
+exit