Fix handling of dedented continuation lines. (#472)

* Fix handling of dedented continuation lines.

- Dedent the function definition before parsing it.
- Join continued-lines before attempting to parse the docstring.

* Update release notes

Co-authored-by: Sambhav Kothari <sambhavs.email@gmail.com>

docs/release_notes.rst

@@ -20,6 +20,8 @@ Bug Fixes
   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).
+* Support backslash-continued descriptions in docstrings
+  (#472).
 
 
 5.0.2 - January 8th, 2020

src/pydocstyle/checker.py

@@ -278,7 +278,9 @@ def check_indent(self, definition, docstring):
             indent = self._get_docstring_indent(definition, docstring)
             lines = docstring.split('\n')
             if len(lines) > 1:
-                lines = lines[1:]  # First line does not need indent.
+                # First line and line continuations need no indent.
+                lines = [line for i, line in enumerate(lines)
+                         if i and not lines[i-1].endswith('\\')]
                 indents = [leading_space(l) for l in lines if not is_blank(l)]
                 if set(' \t') == set(''.join(indents) + indent):
                     yield violations.D206()
@@ -703,7 +705,9 @@ def _check_parameters_section(docstring, definition, context):
         """
         docstring_args = set()
         section_level_indent = leading_space(context.line)
-        content = context.following_lines
+        # Join line continuations, then resplit by line.
+        content = (
+            '\n'.join(context.following_lines).replace('\\\n', '').split('\n'))
         for current_line, next_line in zip(content, content[1:]):
             # All parameter definitions in the Numpy parameters
             # section must be at the same indent level as the section

src/tests/test_cases/sections.py

@@ -389,7 +389,6 @@ def test_missing_docstring_another(skip, verbose):  # noqa: D213, D407
 @expect("D417: Missing argument descriptions in the docstring "
         "(argument(s) y are missing descriptions in "
         "'test_missing_numpy_args' docstring)")
-@expect("D207: Docstring is under-indented")
 def test_missing_numpy_args(_private_arg=0, x=1, y=2):  # noqa: D406, D407
     """Toggle the gizmo.
 
@@ -405,13 +404,19 @@ def test_missing_numpy_args(_private_arg=0, x=1, y=2):  # noqa: D406, D407
 class TestNumpy:  # noqa: D203
     """Test class."""
 
-    def test_method(self, test, another_test, _, x=1, y=2, _private_arg=1):  # noqa: D213, D407
+    def test_method(self, test, another_test, z, _, x=1, y=2, _private_arg=1):  # noqa: D213, D407
         """Test a valid args section.
 
+        Some long string with a \
+line continuation.
+
         Parameters
         ----------
         test, another_test
             Some parameters without type.
+        z : some parameter with a very long type description that requires a \
+line continuation.
+            But no further description.
         x, y : int
             Some integer parameters.