Bugfix: Allow comments before module docstring noqa codes (#446)

* Allow comments before module docstring noqa codes

* Add a note to the release notes

* Break after first `noqa` is encountered

The behavior is now the same as on master.

* added integration tests for comment files

* fixed docstring in test_comment_plus_docstring_file

* added integration tests with noqa

Co-authored-by: Cielquan <cielquan@protonmail.com>
Co-authored-by: Christian Riedel <cannotguessit+github@protonmail.com>
Co-authored-by: Sambhav Kothari <sambhavs.email@gmail.com>

docs/release_notes.rst

@@ -18,6 +18,8 @@ Bug Fixes
 * Fix indentation error while parsing class methods (#441).
 * Fix a bug in parsing Google-style argument description.
   The bug caused some argument names to go unreported in D417 (#448).
+* Fixed an issue where skipping errors on module level docstring via #noqa
+  failed when there where more prior comments (#446).
 
 
 5.0.2 - January 8th, 2020

src/pydocstyle/parser.py

@@ -584,12 +584,20 @@ def parse_definition(self, class_):
     def parse_skip_comment(self):
         """Parse a definition comment for noqa skips."""
         skipped_error_codes = ''
-        if self.current.kind == tk.COMMENT:
-            if 'noqa: ' in self.current.value:
-                skipped_error_codes = ''.join(
-                     self.current.value.split('noqa: ')[1:])
-            elif self.current.value.startswith('# noqa'):
-                skipped_error_codes = 'all'
+        while self.current.kind in (tk.COMMENT, tk.NEWLINE, tk.NL):
+            if self.current.kind == tk.COMMENT:
+                if 'noqa: ' in self.current.value:
+                    skipped_error_codes = ''.join(
+                        self.current.value.split('noqa: ')[1:])
+                elif self.current.value.startswith('# noqa'):
+                    skipped_error_codes = 'all'
+            self.stream.move()
+            self.log.debug("parsing comments before docstring, token is %r (%s)",
+                           self.current.kind, self.current.value)
+
+            if skipped_error_codes:
+                break
+
         return skipped_error_codes
 
     def check_current(self, kind=None, value=None):

src/tests/test_cases/noqa.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # noqa: D400,D415
 """Test case for "# noqa" comments"""
 from .expected import Expectation

src/tests/test_integration.py

@@ -1123,3 +1123,70 @@ def bar(a):
     out, err, code = env.invoke(args="-v")
     assert code == 0
     assert "IndentationError: unexpected indent" not in err
+
+
+def test_only_comment_file(env):
+    """Test that file with only comments does only cause D100."""
+    with env.open('comments.py', 'wt') as comments:
+        comments.write(
+            '#!/usr/bin/env python3\n'
+            '# -*- coding: utf-8 -*-\n'
+            '# Useless comment\n'
+            '# Just another useless comment\n'
+        )
+
+    out, _, code = env.invoke()
+    assert 'D100' in out
+    out = out.replace('D100', '')
+    for err in {'D1', 'D2', 'D3', 'D4'}:
+        assert err not in out
+    assert code == 1
+
+
+def test_comment_plus_docstring_file(env):
+    """Test that file with comments and docstring does not cause errors."""
+    with env.open('comments_plus.py', 'wt') as comments_plus:
+        comments_plus.write(
+            '#!/usr/bin/env python3\n'
+            '# -*- coding: utf-8 -*-\n'
+            '# Useless comment\n'
+            '# Just another useless comment\n'
+            '"""Module docstring."""\n'
+        )
+
+    out, _, code = env.invoke()
+    assert '' == out
+    assert code == 0
+
+
+def test_only_comment_with_noqa_file(env):
+    """Test that file with noqa and only comments does not cause errors."""
+    with env.open('comments.py', 'wt') as comments:
+        comments.write(
+            '#!/usr/bin/env python3\n'
+            '# -*- coding: utf-8 -*-\n'
+            '# Useless comment\n'
+            '# Just another useless comment\n'
+            '# noqa: D100\n'
+        )
+
+    out, _, code = env.invoke()
+    assert 'D100' not in out
+    assert code == 0
+
+
+def test_comment_with_noqa_plus_docstring_file(env):
+    """Test that file with comments, noqa, docstring does not cause errors."""
+    with env.open('comments_plus.py', 'wt') as comments_plus:
+        comments_plus.write(
+            '#!/usr/bin/env python3\n'
+            '# -*- coding: utf-8 -*-\n'
+            '# Useless comment\n'
+            '# Just another useless comment\n'
+            '# noqa: D400\n'
+            '"""Module docstring without period"""\n'
+        )
+
+    out, _, code = env.invoke()
+    assert '' == out
+    assert code == 0