1 files changed, 108 insertions, 0 deletions
diff --git a/pw_presubmit/py/pw_presubmit/todo_check.py b/pw_presubmit/py/pw_presubmit/todo_check.py
new file mode 100644
index 000000000..783667f10
--- /dev/null
+++ b/pw_presubmit/py/pw_presubmit/todo_check.py
@@ -0,0 +1,108 @@
+# Copyright 2022 The Pigweed Authors
+#
+# 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
+#
+#     https://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.
+"""Check the formatting of TODOs."""
+
+import logging
+from pathlib import Path
+import re
+from typing import Iterable, Pattern, Sequence, Union
+
+from pw_presubmit import PresubmitContext, filter_paths
+
+_LOG: logging.Logger = logging.getLogger(__name__)
+
+EXCLUDE: Sequence[str] = (
+    # Metadata
+    r'^docker/tag$',
+    r'\byarn.lock$',
+    # Data files
+    r'\.bin$',
+    r'\.csv$',
+    r'\.elf$',
+    r'\.gif$',
+    r'\.jpg$',
+    r'\.json$',
+    r'\.png$',
+    r'\.svg$',
+    r'\.xml$',
+)
+
+# todo-check: disable
+BUGS_ONLY = re.compile(r'\bTODO\(b/\d+(?:, ?b/\d+)*\).*\w')
+BUGS_OR_USERNAMES = re.compile(
+    r'\bTODO\((?:b/\d+|[a-z]+)(?:, ?(?:b/\d+|[a-z]+))*\).*\w'
+)
+_TODO = re.compile(r'\bTODO\b')
+# todo-check: enable
+
+# If seen, ignore this line and the next.
+_IGNORE = 'todo-check: ignore'
+
+# Ignore a whole section. Please do not change the order of these lines.
+_DISABLE = 'todo-check: disable'
+_ENABLE = 'todo-check: enable'
+
+
+def _process_file(ctx: PresubmitContext, todo_pattern: re.Pattern, path: Path):
+    with path.open() as ins:
+        _LOG.debug('Evaluating path %s', path)
+        enabled = True
+        prev = ''
+
+        try:
+            summary = []
+            for i, line in enumerate(ins, 1):
+                if _DISABLE in line:
+                    enabled = False
+                elif _ENABLE in line:
+                    enabled = True
+
+                if not enabled or _IGNORE in line or _IGNORE in prev:
+                    prev = line
+                    continue
+
+                if _TODO.search(line):
+                    if not todo_pattern.search(line):
+                        # todo-check: ignore
+                        ctx.fail(f'Bad TODO on line {i}:', path)
+                        ctx.fail(f'    {line.strip()}')
+                        summary.append(
+                            f'{path.relative_to(ctx.root)}:{i}:{line.strip()}'
+                        )
+
+                prev = line
+
+            if summary:
+                with ctx.failure_summary_log.open('w') as outs:
+                    for line in summary:
+                        print(line, file=outs)
+
+        except UnicodeDecodeError:
+            # File is not text, like a gif.
+            _LOG.debug('File %s is not a text file', path)
+
+
+def create(
+    todo_pattern: re.Pattern = BUGS_ONLY,
+    exclude: Iterable[Union[Pattern[str], str]] = EXCLUDE,
+):
+    """Create a todo_check presubmit step that uses the given pattern."""
+
+    @filter_paths(exclude=exclude)
+    def todo_check(ctx: PresubmitContext):
+        """Check that TODO lines are valid."""  # todo-check: ignore
+        for path in ctx.paths:
+            _process_file(ctx, todo_pattern, path)
+
+    return todo_check