add a lint command

Provide a tool for doing some basic input validation.

Related-Bug: #1688042
Change-Id: I850b57153c5286e19f4ac3af899b3d798aebd7d4
Signed-off-by: Doug Hellmann <doug@doughellmann.com>

doc/source/usage.rst

@@ -162,6 +162,15 @@ Notes are output in the order they are found when scanning the git
 history of the branch using topological ordering. This is
 deterministic, but not necessarily predictable or mutable.
 
+Checking Notes
+==============
+
+Run ``reno lint <path-to-git-repository>`` to test the existing
+release notes files against some rules for catching common
+mistakes. The command exits with an error code if there are any
+mistakes, so it can be used in a build pipeline to force some
+correctness.
+
 Configuring Reno
 ================
 

releasenotes/notes/add-linter-ce0a861ade64baf2.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Add a ``lint`` command for checking the contents and names of the
+    release notes files against some basic validation rules.

reno/linter.py

@@ -0,0 +1,54 @@
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+from __future__ import print_function
+
+import glob
+import logging
+import os.path
+
+from reno import loader
+from reno import scanner
+
+LOG = logging.getLogger(__name__)
+
+
+def lint_cmd(args, conf):
+    "Check some common mistakes"
+    LOG.debug('starting lint')
+    notesdir = os.path.join(conf.reporoot, conf.notespath)
+    notes = glob.glob(os.path.join(notesdir, '*.yaml'))
+
+    error = 0
+    load = loader.Loader(conf, ignore_cache=True)
+
+    allowed_section_names = ['prelude'] + [s[0] for s in conf.sections]
+
+    uids = {}
+    for f in notes:
+        LOG.debug('examining %s', f)
+        uid = scanner._get_unique_id(f)
+        uids.setdefault(uid, []).append(f)
+
+        content = load.parse_note_file(f, None)
+        for section_name in content.keys():
+            if section_name not in allowed_section_names:
+                LOG.warning('unrecognized section name %s in %s',
+                            section_name, f)
+                error = 1
+
+    for uid, names in sorted(uids.items()):
+        if len(names) > 1:
+            LOG.warning('UID collision: %s', names)
+            error = 1
+
+    return error

reno/main.py

@@ -18,6 +18,7 @@ from reno import cache
 from reno import config
 from reno import create
 from reno import defaults
+from reno import linter
 from reno import lister
 from reno import report
 
@@ -173,6 +174,18 @@ def main(argv=sys.argv[1:]):
     _build_query_arg_group(do_cache)
     do_cache.set_defaults(func=cache.cache_cmd)
 
+    do_linter = subparsers.add_parser(
+        'lint',
+        help='check some common mistakes',
+    )
+    do_linter.add_argument(
+        'reporoot',
+        default='.',
+        nargs='?',
+        help='root of the git repository',
+    )
+    do_linter.set_defaults(func=linter.lint_cmd)
+
     args = parser.parse_args(argv)
     conf = config.Config(args.reporoot, args.relnotesdir)
     conf.override_from_parsed_args(args)

tox.ini

@@ -16,7 +16,9 @@ commands =
     coverage report --show-missing
 
 [testenv:pep8]
-commands = flake8
+commands =
+  flake8
+  reno -q lint
 
 [testenv:venv]
 commands = {posargs}