Removed adding a space into empty docstrings. (#2249)

Resolves #2168 by disabling the insertion of a " " when the docstring is entirely empty.

Note that this PR is focussed only on the case of empty docstrings. In particular this does not make any changes to the behaviour that a " " is inserted if a non-empty docstring begins with the quoting character. That is, black still prefers:

    """ "something" """

to:

    """"something" """

and that:

    """"Something""""

is not a legal docstring.

diff --git a/CHANGES.md b/CHANGES.md
index 22939e38c122d2e5a3e35c8a81fc22f9f8706e39..1b7a54a516d188a189d22d141861097b6e2a4476 100644 (file)
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -4,6 +4,7 @@
 
 ### _Black_
 
+- A space is no longer inserted into empty docstrings (#2249)
 - Fix handling of .gitignore files containing non-ASCII characters on Windows (#2229)
 - Respect `.gitignore` files in all levels, not only `root/.gitignore` file (apply
   `.gitignore` rules like `git` does) (#2225)

diff --git a/src/black/linegen.py b/src/black/linegen.py
index 2e16b6fde4457d24c06992a57d1324e63675d9e4..7949654b40e5a4dee405c1182816a5f4363f0f87 100644 (file)
--- a/src/black/linegen.py
+++ b/src/black/linegen.py
@@ -236,6 +236,7 @@ class LineGenerator(Visitor[Line]):
             # characters but only if they are the same as the first.
             quote_len = 1 if docstring[1] != quote_char else 3
             docstring = docstring[quote_len:-quote_len]
+            docstring_started_empty = not docstring
 
             if is_multiline_string(leaf):
                 indent = " " * 4 * self.current_line.depth
@@ -255,8 +256,7 @@ class LineGenerator(Visitor[Line]):
                         # Odd number of tailing backslashes, add some padding to
                         # avoid escaping the closing string quote.
                         docstring += " "
-            else:
-                # Add some padding if the docstring is empty.
+            elif not docstring_started_empty:
                 docstring = " "
 
             # We could enforce triple quotes at this point.

diff --git a/tests/data/docstring.py b/tests/data/docstring.py
index e977619e482195ee784789bdd6a40ca592aa9040..96bcf525b16fe56538739f4c895e021a4766dadd 100644 (file)
--- a/tests/data/docstring.py
+++ b/tests/data/docstring.py
@@ -102,7 +102,7 @@ def and_this():
   "hey yah"'''
 
 
-def empty():
+def multiline_whitespace():
     '''
     
     
@@ -111,11 +111,11 @@ def empty():
     '''
 
 
-def oneline_empty():
+def oneline_whitespace():
     '''      '''
 
 
-def oneline_nothing():
+def empty():
     """"""
 
 
@@ -293,16 +293,16 @@ def and_this():
     "hey yah"'''
 
 
-def empty():
+def multiline_whitespace():
     """ """
 
 
-def oneline_empty():
+def oneline_whitespace():
     """ """
 
 
-def oneline_nothing():
-    """ """
+def empty():
+    """"""
 
 
 def single_quotes():
@@ -374,4 +374,4 @@ def my_god_its_full_of_stars_1():
 
 # the space below is actually a \u2001, removed in output
 def my_god_its_full_of_stars_2():
-    "I'm sorry Dave"
\ No newline at end of file
+    "I'm sorry Dave"