Preserve visible quote types for f-string debug expressions

CHANGES.md

@@ -17,6 +17,7 @@
  indented less (#3964)
 - Multiline list and dict unpacking as the sole argument to a function is now also
  indented less (#3992)
+- Preserve printable quote types for debug f-strings (#4005)
 
 ### Configuration
 

src/black/trans.py

@@ -590,11 +590,20 @@ def make_naked(string: str, string_prefix: str) -> str:
  """
  assert_is_leaf_string(string)
  if "f" in string_prefix:
- string = _toggle_fexpr_quotes(string, QUOTE)
- # After quotes toggling, quotes in expressions won't be escaped
- # because quotes can't be reused in f-strings. So we can simply
- # let the escaping logic below run without knowing f-string
- # expressions.
+ RE_QUOTES_IN_DEBUG_F_STRING = (
+ r"{[^[]*\[\s*[\"\']\w*[\"\']\s*\][^=}]*=[^}]*}"
+ )
+ is_debug_f_string_with_quotes = re.search(
+ RE_QUOTES_IN_DEBUG_F_STRING, string
+ )
+ if not is_debug_f_string_with_quotes:
+ # We don't want to toggle debug f-string quotes in the printable
+ # part, because that would modify the AST
+ string = _toggle_fexpr_quotes(string, QUOTE)
+ # After quotes toggling, quotes in expressions won't be escaped
+ # because quotes can't be reused in f-strings. So we can simply
+ # let the escaping logic below run without knowing f-string
+ # expressions.
 
  RE_EVEN_BACKSLASHES = r"(?:(?<!\\)(?:\\\\)*)"
  naked_string = string[len(string_prefix) + 1 : -1]

tests/data/cases/preview_long_strings.py

@@ -305,6 +305,13 @@ def foo():
 # Test case of an outer string' parens enclose an inner string's parens.
 call(body=("%s %s" % ((",".join(items)), suffix)))
 
+log.info(f'Skipping: {desc["db_id"]=} {desc["ms_name"]} {money=} {dte=} {pos_share=} {desc["status"]=} {desc["exposure_max"]=}')
+
+log.info(f"Skipping: {desc['db_id']=} {desc['ms_name']} {money=} {dte=} {pos_share=} {desc['status']=} {desc['exposure_max']=}")
+
+log.info(f'Skipping: {desc["db_id"]} {desc["ms_name"]} {money=} {dte=} {pos_share=} {desc["status"]} {desc["exposure_max"]}')
+
+log.info(f'Skipping: { longer_longer_longer_longer_longer_longer_name [ "db_id" ] [ "another_key" ] = : .3f }')
 
 # output
 
@@ -846,3 +853,23 @@ def foo():
 
 # Test case of an outer string' parens enclose an inner string's parens.
 call(body="%s %s" % (",".join(items), suffix))
+
+log.info(
+ "Skipping:"
+ f' {desc["db_id"]=} {desc["ms_name"]} {money=} {dte=} {pos_share=} {desc["status"]=} {desc["exposure_max"]=}'
+)
+
+log.info(
+ "Skipping:"
+ f" {desc['db_id']=} {desc['ms_name']} {money=} {dte=} {pos_share=} {desc['status']=} {desc['exposure_max']=}"
+)
+
+log.info(
+ "Skipping:"
+ f" {desc['db_id']} {desc['ms_name']} {money=} {dte=} {pos_share=} {desc['status']} {desc['exposure_max']}"
+)
+
+log.info(
+ "Skipping:"
+ f' { longer_longer_longer_longer_longer_longer_name [ "db_id" ] [ "another_key" ] = : .3f }'
+)