Mention comment non-processing in documentation (#2306)

[etc/vim.git] / src / black / trans.py

diff --git a/src/black/trans.py b/src/black/trans.py
index 80e88a2d2fb78d834ed281256b8b3dd97511a16a..4fb2c4d01440b89ef9c6408d3c94cc9e4745f018 100644 (file)
--- a/src/black/trans.py
+++ b/src/black/trans.py
@@ -738,6 +738,18 @@ class BaseStringSplitter(StringTransformer):
         * The target string is not a multiline (i.e. triple-quote) string.
     """
 
+    STRING_OPERATORS = [
+        token.EQEQUAL,
+        token.GREATER,
+        token.GREATEREQUAL,
+        token.LESS,
+        token.LESSEQUAL,
+        token.NOTEQUAL,
+        token.PERCENT,
+        token.PLUS,
+        token.STAR,
+    ]
+
     @abstractmethod
     def do_splitter_match(self, line: Line) -> TMatchResult:
         """
@@ -847,15 +859,15 @@ class BaseStringSplitter(StringTransformer):
                 p_idx -= 1
 
             P = LL[p_idx]
-            if P.type == token.PLUS:
-                # WMA4 a space and a '+' character (e.g. `+ STRING`).
-                offset += 2
+            if P.type in self.STRING_OPERATORS:
+                # WMA4 a space and a string operator (e.g. `+ STRING` or `== STRING`).
+                offset += len(str(P)) + 1
 
             if P.type == token.COMMA:
                 # WMA4 a space, a comma, and a closing bracket [e.g. `), STRING`].
                 offset += 3
 
-            if P.type in [token.COLON, token.EQUAL, token.NAME]:
+            if P.type in [token.COLON, token.EQUAL, token.PLUSEQUAL, token.NAME]:
                 # This conditional branch is meant to handle dictionary keys,
                 # variable assignments, 'return STRING' statement lines, and
                 # 'else STRING' ternary expression lines.
@@ -952,16 +964,6 @@ class StringSplitter(CustomSplitMapMixin, BaseStringSplitter):
         CustomSplit objects and add them to the custom split map.
     """
 
-    STRING_OPERATORS = [
-        token.PLUS,
-        token.STAR,
-        token.EQEQUAL,
-        token.NOTEQUAL,
-        token.LESS,
-        token.LESSEQUAL,
-        token.GREATER,
-        token.GREATEREQUAL,
-    ]
     MIN_SUBSTR_SIZE = 6
     # Matches an "f-expression" (e.g. {var}) that might be found in an f-string.
     RE_FEXPR = r"""
@@ -971,8 +973,8 @@ class StringSplitter(CustomSplitMapMixin, BaseStringSplitter):
             | \{\{
             | \}\}
             | (?R)
-        )+?
-    (?<!\}) \} (?:\}\})* (?!\})
+        )+
+    \}
     """
 
     def do_splitter_match(self, line: Line) -> TMatchResult:
@@ -1149,21 +1151,32 @@ class StringSplitter(CustomSplitMapMixin, BaseStringSplitter):
 
             # --- Construct `next_value`
             next_value = rest_value[:break_idx] + QUOTE
+
+            # HACK: The following 'if' statement is a hack to fix the custom
+            # breakpoint index in the case of either: (a) substrings that were
+            # f-strings but will have the 'f' prefix removed OR (b) substrings
+            # that were not f-strings but will now become f-strings because of
+            # redundant use of the 'f' prefix (i.e. none of the substrings
+            # contain f-expressions but one or more of them had the 'f' prefix
+            # anyway; in which case, we will prepend 'f' to _all_ substrings).
+            #
+            # There is probably a better way to accomplish what is being done
+            # here...
+            #
+            # If this substring is an f-string, we _could_ remove the 'f'
+            # prefix, and the current custom split did NOT originally use a
+            # prefix...
             if (
-                # Are we allowed to try to drop a pointless 'f' prefix?
-                drop_pointless_f_prefix
-                # If we are, will we be successful?
-                and next_value != self._normalize_f_string(next_value, prefix)
+                next_value != self._normalize_f_string(next_value, prefix)
+                and use_custom_breakpoints
+                and not csplit.has_prefix
             ):
-                # If the current custom split did NOT originally use a prefix,
-                # then `csplit.break_idx` will be off by one after removing
+                # Then `csplit.break_idx` will be off by one after removing
                 # the 'f' prefix.
-                break_idx = (
-                    break_idx + 1
-                    if use_custom_breakpoints and not csplit.has_prefix
-                    else break_idx
-                )
+                break_idx += 1
                 next_value = rest_value[:break_idx] + QUOTE
+
+            if drop_pointless_f_prefix:
                 next_value = self._normalize_f_string(next_value, prefix)
 
             # --- Construct `next_leaf`