Don't split on for-loop variable unpacks

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 64df7f7d67ee6353002d435bb4a873516a872cac..774d91dc2a7f64ec2dbc252a55e0fe051d5c429c 100644 (file)
--- a/black.py
+++ b/black.py
@@ -55,6 +55,15 @@ class CannotSplit(Exception):
     help='How many character per line to allow.',
     show_default=True,
 )
     help='How many character per line to allow.',
     show_default=True,
 )

+@click.option(
+    '--check',
+    is_flag=True,
+    help=(
+        "Don't write back the files, just return the status.  Return code 0 "
+        "means nothing changed.  Return code 1 means some files were "
+        "reformatted.  Return code 123 means there was an internal error."
+    ),
+)

 @click.option(
     '--fast/--safe',
     is_flag=True,
 @click.option(
     '--fast/--safe',
     is_flag=True,


@@ -67,7 +76,9 @@ class CannotSplit(Exception):
     type=click.Path(exists=True, file_okay=True, dir_okay=True, readable=True),
 )
 @click.pass_context
     type=click.Path(exists=True, file_okay=True, dir_okay=True, readable=True),
 )
 @click.pass_context

-def main(ctx: click.Context, line_length: int, fast: bool, src: List[str]) -> None:
+def main(
+    ctx: click.Context, line_length: int, check: bool, fast: bool, src: List[str]
+) -> None:

     """The uncompromising code formatter."""
     sources: List[Path] = []
     for s in src:
     """The uncompromising code formatter."""
     sources: List[Path] = []
     for s in src:


@@ -85,7 +96,9 @@ def main(ctx: click.Context, line_length: int, fast: bool, src: List[str]) -> No
         p = sources[0]
         report = Report()
         try:
         p = sources[0]
         report = Report()
         try:

-            changed = format_file_in_place(p, line_length=line_length, fast=fast)
+            changed = format_file_in_place(
+                p, line_length=line_length, fast=fast, write_back=not check
+            )

             report.done(p, changed)
         except Exception as exc:
             report.failed(p, str(exc))
             report.done(p, changed)
         except Exception as exc:
             report.failed(p, str(exc))


@@ -96,7 +109,9 @@ def main(ctx: click.Context, line_length: int, fast: bool, src: List[str]) -> No
         return_code = 1
         try:
             return_code = loop.run_until_complete(
         return_code = 1
         try:
             return_code = loop.run_until_complete(

-                schedule_formatting(sources, line_length, fast, loop, executor)
+                schedule_formatting(
+                    sources, line_length, not check, fast, loop, executor
+                )

             )
         finally:
             loop.close()
             )
         finally:
             loop.close()


@@ -106,13 +121,14 @@ def main(ctx: click.Context, line_length: int, fast: bool, src: List[str]) -> No
 async def schedule_formatting(
     sources: List[Path],
     line_length: int,
 async def schedule_formatting(
     sources: List[Path],
     line_length: int,

+    write_back: bool,

     fast: bool,
     loop: BaseEventLoop,
     executor: Executor,
 ) -> int:
     tasks = {
         src: loop.run_in_executor(
     fast: bool,
     loop: BaseEventLoop,
     executor: Executor,
 ) -> int:
     tasks = {
         src: loop.run_in_executor(

-            executor, format_file_in_place, src, line_length, fast
+            executor, format_file_in_place, src, line_length, fast, write_back

         )
         for src in sources
     }
         )
         for src in sources
     }


@@ -135,15 +151,18 @@ async def schedule_formatting(
     return report.return_code
 
 
     return report.return_code
 
 

-def format_file_in_place(src: Path, line_length: int, fast: bool) -> bool:
+def format_file_in_place(
+    src: Path, line_length: int, fast: bool, write_back: bool = False
+) -> bool:

     """Format the file and rewrite if changed. Return True if changed."""
     try:
         contents, encoding = format_file(src, line_length=line_length, fast=fast)
     except NothingChanged:
         return False
 
     """Format the file and rewrite if changed. Return True if changed."""
     try:
         contents, encoding = format_file(src, line_length=line_length, fast=fast)
     except NothingChanged:
         return False
 

-    with open(src, "w", encoding=encoding) as f:
-        f.write(contents)
+    if write_back:
+        with open(src, "w", encoding=encoding) as f:
+            f.write(contents)

     return True
 
 
     return True
 
 


@@ -358,7 +377,7 @@ class BracketTracker:
         """Returns True if there is an yet unmatched open bracket on the line."""
         return bool(self.bracket_match)
 
         """Returns True if there is an yet unmatched open bracket on the line."""
         return bool(self.bracket_match)
 

-    def max_priority(self, exclude: Iterable[LeafID] = ()) -> int:
+    def max_priority(self, exclude: Iterable[LeafID] =()) -> int:

         """Returns the highest priority of a delimiter found on the line.
 
         Values are consistent with what `is_delimiter()` returns.
         """Returns the highest priority of a delimiter found on the line.
 
         Values are consistent with what `is_delimiter()` returns.


@@ -373,6 +392,8 @@ class Line:
     comments: Dict[LeafID, Leaf] = attrib(default=Factory(dict))
     bracket_tracker: BracketTracker = attrib(default=Factory(BracketTracker))
     inside_brackets: bool = attrib(default=False)
     comments: Dict[LeafID, Leaf] = attrib(default=Factory(dict))
     bracket_tracker: BracketTracker = attrib(default=Factory(BracketTracker))
     inside_brackets: bool = attrib(default=False)

+    has_for: bool = attrib(default=False)
+    _for_loop_variable: bool = attrib(default=False, init=False)

 
     def append(self, leaf: Leaf, preformatted: bool = False) -> None:
         has_value = leaf.value.strip()
 
     def append(self, leaf: Leaf, preformatted: bool = False) -> None:
         has_value = leaf.value.strip()


@@ -384,8 +405,10 @@ class Line:
             # imports, for which we only preserve newlines.
             leaf.prefix += whitespace(leaf)
         if self.inside_brackets or not preformatted:
             # imports, for which we only preserve newlines.
             leaf.prefix += whitespace(leaf)
         if self.inside_brackets or not preformatted:

+            self.maybe_decrement_after_for_loop_variable(leaf)

             self.bracket_tracker.mark(leaf)
             self.maybe_remove_trailing_comma(leaf)
             self.bracket_tracker.mark(leaf)
             self.maybe_remove_trailing_comma(leaf)

+            self.maybe_increment_for_loop_variable(leaf)

             if self.maybe_adapt_standalone_comment(leaf):
                 return
 
             if self.maybe_adapt_standalone_comment(leaf):
                 return
 


@@ -489,6 +512,29 @@ class Line:
 
         return False
 
 
         return False
 

+    def maybe_increment_for_loop_variable(self, leaf: Leaf) -> bool:
+        """In a for loop, or comprehension, the variables are often unpacks.
+
+        To avoid splitting on the comma in this situation, we will increase
+        the depth of tokens between `for` and `in`.
+        """
+        if leaf.type == token.NAME and leaf.value == 'for':
+            self.has_for = True
+            self.bracket_tracker.depth += 1
+            self._for_loop_variable = True
+            return True
+
+        return False
+
+    def maybe_decrement_after_for_loop_variable(self, leaf: Leaf) -> bool:
+        # See `maybe_increment_for_loop_variable` above for explanation.
+        if self._for_loop_variable and leaf.type == token.NAME and leaf.value == 'in':
+            self.bracket_tracker.depth -= 1
+            self._for_loop_variable = False
+            return True
+
+        return False
+

     def maybe_adapt_standalone_comment(self, comment: Leaf) -> bool:
         """Hack a standalone comment to act as a trailing comment for line splitting.
 
     def maybe_adapt_standalone_comment(self, comment: Leaf) -> bool:
         """Hack a standalone comment to act as a trailing comment for line splitting.
 


@@ -781,13 +827,51 @@ def whitespace(leaf: Leaf) -> str:
     if t == STANDALONE_COMMENT:
         return NO
 
     if t == STANDALONE_COMMENT:
         return NO
 

+    if t in CLOSING_BRACKETS:
+        return NO
+

     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"

+    prev = leaf.prev_sibling
+    if not prev:
+        prevp = preceding_leaf(p)
+        if not prevp or prevp.type in OPENING_BRACKETS:
+            return NO
+
+        if prevp.type == token.EQUAL:
+            if prevp.parent and prevp.parent.type in {
+                syms.typedargslist,
+                syms.varargslist,
+                syms.parameters,
+                syms.arglist,
+                syms.argument,
+            }:
+                return NO
+
+        elif prevp.type == token.DOUBLESTAR:
+            if prevp.parent and prevp.parent.type in {
+                syms.typedargslist,
+                syms.varargslist,
+                syms.parameters,
+                syms.arglist,
+                syms.dictsetmaker,
+            }:
+                return NO
+
+        elif prevp.type == token.COLON:
+            if prevp.parent and prevp.parent.type == syms.subscript:
+                return NO
+
+        elif prevp.parent and prevp.parent.type == syms.factor:
+            return NO
+
+    elif prev.type in OPENING_BRACKETS:
+        return NO
+

     if p.type in {syms.parameters, syms.arglist}:
         # untyped function signatures or calls
         if t == token.RPAR:
             return NO
 
     if p.type in {syms.parameters, syms.arglist}:
         # untyped function signatures or calls
         if t == token.RPAR:
             return NO
 

-        prev = leaf.prev_sibling

         if not prev or prev.type != token.COMMA:
             return NO
 
         if not prev or prev.type != token.COMMA:
             return NO
 


@@ -796,13 +880,11 @@ def whitespace(leaf: Leaf) -> str:
         if t == token.RPAR:
             return NO
 
         if t == token.RPAR:
             return NO
 

-        prev = leaf.prev_sibling

         if prev and prev.type != token.COMMA:
             return NO
 
     elif p.type == syms.typedargslist:
         # typed function signatures
         if prev and prev.type != token.COMMA:
             return NO
 
     elif p.type == syms.typedargslist:
         # typed function signatures

-        prev = leaf.prev_sibling

         if not prev:
             return NO
 
         if not prev:
             return NO
 


@@ -820,7 +902,6 @@ def whitespace(leaf: Leaf) -> str:
 
     elif p.type == syms.tname:
         # type names
 
     elif p.type == syms.tname:
         # type names

-        prev = leaf.prev_sibling

         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type != token.COMMA:
         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type != token.COMMA:


@@ -831,7 +912,6 @@ def whitespace(leaf: Leaf) -> str:
         if t == token.LPAR or t == token.RPAR:
             return NO
 
         if t == token.LPAR or t == token.RPAR:
             return NO
 

-        prev = leaf.prev_sibling

         if not prev:
             if t == token.DOT:
                 prevp = preceding_leaf(p)
         if not prev:
             if t == token.DOT:
                 prevp = preceding_leaf(p)


@@ -849,7 +929,6 @@ def whitespace(leaf: Leaf) -> str:
         if t == token.EQUAL:
             return NO
 
         if t == token.EQUAL:
             return NO
 

-        prev = leaf.prev_sibling

         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type == token.LPAR:
         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type == token.LPAR:


@@ -863,7 +942,6 @@ def whitespace(leaf: Leaf) -> str:
         return NO
 
     elif p.type == syms.dotted_name:
         return NO
 
     elif p.type == syms.dotted_name:

-        prev = leaf.prev_sibling

         if prev:
             return NO
 
         if prev:
             return NO
 


@@ -875,77 +953,16 @@ def whitespace(leaf: Leaf) -> str:
         if t == token.LPAR:
             return NO
 
         if t == token.LPAR:
             return NO
 

-        prev = leaf.prev_sibling

         if prev and prev.type == token.LPAR:
             return NO
 
     elif p.type == syms.subscript:
         # indexing
         if prev and prev.type == token.LPAR:
             return NO
 
     elif p.type == syms.subscript:
         # indexing

-        if t == token.COLON:
-            return NO
-
-        prev = leaf.prev_sibling

         if not prev or prev.type == token.COLON:
             return NO
 
         if not prev or prev.type == token.COLON:
             return NO
 

-    elif p.type in {
-        syms.test,
-        syms.not_test,
-        syms.xor_expr,
-        syms.or_test,
-        syms.and_test,
-        syms.arith_expr,
-        syms.expr,
-        syms.shift_expr,
-        syms.yield_expr,
-        syms.term,
-        syms.power,
-        syms.comparison,
-    }:
-        # various arithmetic and logic expressions
-        prev = leaf.prev_sibling
-        if not prev:
-            prevp = preceding_leaf(p)
-            if not prevp or prevp.type in OPENING_BRACKETS:
-                return NO
-
-            if prevp.type == token.EQUAL:
-                if prevp.parent and prevp.parent.type in {
-                    syms.varargslist, syms.parameters, syms.arglist, syms.argument
-                }:
-                    return NO
-
-        return SPACE
-

     elif p.type == syms.atom:
     elif p.type == syms.atom:

-        if t in CLOSING_BRACKETS:
-            return NO
-
-        prev = leaf.prev_sibling
-        if not prev:
-            prevp = preceding_leaf(p)
-            if not prevp:
-                return NO
-
-            if prevp.type in OPENING_BRACKETS:
-                return NO
-
-            if prevp.type == token.EQUAL:
-                if prevp.parent and prevp.parent.type in {
-                    syms.varargslist, syms.parameters, syms.arglist, syms.argument
-                }:
-                    return NO
-
-            if prevp.type == token.DOUBLESTAR:
-                if prevp.parent and prevp.parent.type in {
-                    syms.varargslist, syms.parameters, syms.arglist, syms.dictsetmaker
-                }:
-                    return NO
-
-        elif prev.type in OPENING_BRACKETS:
-            return NO
-
-        elif t == token.DOT:
+        if prev and t == token.DOT:

             # dots, but not the first one.
             return NO
 
             # dots, but not the first one.
             return NO
 


@@ -955,13 +972,11 @@ def whitespace(leaf: Leaf) -> str:
         p.type == syms.subscriptlist
     ):
         # list interior, including unpacking
         p.type == syms.subscriptlist
     ):
         # list interior, including unpacking

-        prev = leaf.prev_sibling

         if not prev:
             return NO
 
     elif p.type == syms.dictsetmaker:
         # dict and set interior, including unpacking
         if not prev:
             return NO
 
     elif p.type == syms.dictsetmaker:
         # dict and set interior, including unpacking

-        prev = leaf.prev_sibling

         if not prev:
             return NO
 
         if not prev:
             return NO
 


@@ -970,7 +985,6 @@ def whitespace(leaf: Leaf) -> str:
 
     elif p.type == syms.factor or p.type == syms.star_expr:
         # unary ops
 
     elif p.type == syms.factor or p.type == syms.star_expr:
         # unary ops

-        prev = leaf.prev_sibling

         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type in OPENING_BRACKETS:
         if not prev:
             prevp = preceding_leaf(p)
             if not prevp or prevp.type in OPENING_BRACKETS:


@@ -991,7 +1005,6 @@ def whitespace(leaf: Leaf) -> str:
 
     elif p.type == syms.import_from:
         if t == token.DOT:
 
     elif p.type == syms.import_from:
         if t == token.DOT:

-            prev = leaf.prev_sibling

             if prev and prev.type == token.DOT:
                 return NO
 
             if prev and prev.type == token.DOT:
                 return NO
 


@@ -999,7 +1012,6 @@ def whitespace(leaf: Leaf) -> str:
             if v == 'import':
                 return SPACE
 
             if v == 'import':
                 return SPACE
 

-            prev = leaf.prev_sibling

             if prev and prev.type == token.DOT:
                 return NO
 
             if prev and prev.type == token.DOT:
                 return NO
 


@@ -1355,7 +1367,15 @@ class Report:
     @property
     def return_code(self) -> int:
         """Which return code should the app use considering the current state."""
     @property
     def return_code(self) -> int:
         """Which return code should the app use considering the current state."""

-        return 1 if self.failure_count else 0
+        # According to http://tldp.org/LDP/abs/html/exitcodes.html starting with
+        # 126 we have special returncodes reserved by the shell.
+        if self.failure_count:
+            return 123
+
+        elif self.change_count:
+            return 1
+
+        return 0

 
     def __str__(self) -> str:
         """A color report of the current state.
 
     def __str__(self) -> str:
         """A color report of the current state.