Make black remove leading and trailing spaces from one-line docstrings: fixes #1738 #1812

CHANGES.md

@@ -4,6 +4,8 @@
 
 #### _Black_
 
+- `Black` now requires one-line docstrings to be stripped (PR #1740)
+
 - `Black` now respects `--skip-string-normalization` when normalizing multiline
   docstring quotes (#1637)
 

src/black/__init__.py

@@ -2138,8 +2138,12 @@ def visit_STRING(self, leaf: Leaf) -> Iterator[Line]:
             prefix = get_string_prefix(leaf.value)
             lead_len = len(prefix) + 3
             tail_len = -3
-            indent = " " * 4 * self.current_line.depth
-            docstring = fix_docstring(leaf.value[lead_len:tail_len], indent)
+            docstring = leaf.value[lead_len:tail_len]
+            if is_multiline_string(leaf):
+                indent = " " * 4 * self.current_line.depth
+                docstring = fix_docstring(docstring, indent)
+            else:
+                docstring = docstring.strip()
             if docstring:
                 if leaf.value[lead_len - 1] == docstring[0]:
                     docstring = " " + docstring
@@ -6089,7 +6093,7 @@ def get_imports_from_children(children: List[LN]) -> Generator[str, None, None]:
 
 @lru_cache()
 def get_gitignore(root: Path) -> PathSpec:
-    """ Return a PathSpec matching gitignore content if present."""
+    """Return a PathSpec matching gitignore content if present."""
     gitignore = root / ".gitignore"
     lines: List[str] = []
     if gitignore.is_file():
@@ -6908,11 +6912,6 @@ def patched_main() -> None:
 
 
 def is_docstring(leaf: Leaf) -> bool:
-    if not is_multiline_string(leaf):
-        # For the purposes of docstring re-indentation, we don't need to do anything
-        # with single-line docstrings.
-        return False
-
     if prev_siblings_are(
         leaf.parent, [None, token.NEWLINE, token.INDENT, syms.simple_stmt]
     ):

tests/data/docstring.py

@@ -110,6 +110,8 @@ def ignored_docstring():
     """a => \
 b"""  
 
+def single_line_docstring_with_whitespace():
+    """   This should be stripped """
 
 def docstring_with_inline_tabs_and_space_indentation():
     """hey
@@ -134,7 +136,6 @@ def docstring_with_inline_tabs_and_tab_indentation():
 	line ends with some tabs		
 	"""
 	pass
-
 
 # output
 
@@ -251,6 +252,10 @@ def ignored_docstring():
 b"""
 
 
+def single_line_docstring_with_whitespace():
+    """This should be stripped"""
+
+
 def docstring_with_inline_tabs_and_space_indentation():
     """hey
 
@@ -273,4 +278,4 @@ def docstring_with_inline_tabs_and_tab_indentation():
 
     line ends with some tabs
     """
-    pass
+    pass