X-Git-Url: https://git.madduck.net/etc/vim.git/blobdiff_plain/497de7fa08b5072da3cf328e6b870ce2575cb2a7..591bedc2be0cec92c5f253fd473864c876233114:/black.py

diff --git a/black.py b/black.py
index 10346a9..54044a5 100644
--- a/black.py
+++ b/black.py
@@ -74,7 +74,9 @@ class CannotSplit(Exception):
 @click.argument(
     'src',
     nargs=-1,
-    type=click.Path(exists=True, file_okay=True, dir_okay=True, readable=True),
+    type=click.Path(
+        exists=True, file_okay=True, dir_okay=True, readable=True, allow_dash=True
+    ),
 )
 @click.pass_context
 def main(
@@ -89,6 +91,8 @@ def main(
         elif p.is_file():
             # if a file was explicitly given, we don't care about its extension
             sources.append(p)
+        elif s == '-':
+            sources.append(Path('-'))
         else:
             err(f'invalid path: {s}')
     if len(sources) == 0:
@@ -97,9 +101,14 @@ def main(
         p = sources[0]
         report = Report()
         try:
-            changed = format_file_in_place(
-                p, line_length=line_length, fast=fast, write_back=not check
-            )
+            if not p.is_file() and str(p) == '-':
+                changed = format_stdin_to_stdout(
+                    line_length=line_length, fast=fast, write_back=not check
+                )
+            else:
+                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))
@@ -156,34 +165,53 @@ 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."""
+    with tokenize.open(src) as src_buffer:
+        src_contents = src_buffer.read()
     try:
-        contents, encoding = format_file(src, line_length=line_length, fast=fast)
+        contents = format_file_contents(
+            src_contents, line_length=line_length, fast=fast
+        )
     except NothingChanged:
         return False
 
     if write_back:
-        with open(src, "w", encoding=encoding) as f:
+        with open(src, "w", encoding=src_buffer.encoding) as f:
             f.write(contents)
     return True
 
 
-def format_file(
-    src: Path, line_length: int, fast: bool
-) -> Tuple[FileContent, Encoding]:
+def format_stdin_to_stdout(
+    line_length: int, fast: bool, write_back: bool = False
+) -> bool:
+    """Format file on stdin and pipe output to stdout. Return True if changed."""
+    contents = sys.stdin.read()
+    try:
+        contents = format_file_contents(contents, line_length=line_length, fast=fast)
+        return True
+
+    except NothingChanged:
+        return False
+
+    finally:
+        if write_back:
+            sys.stdout.write(contents)
+
+
+def format_file_contents(
+    src_contents: str, line_length: int, fast: bool
+) -> FileContent:
     """Reformats a file and returns its contents and encoding."""
-    with tokenize.open(src) as src_buffer:
-        src_contents = src_buffer.read()
     if src_contents.strip() == '':
-        raise NothingChanged(src)
+        raise NothingChanged
 
     dst_contents = format_str(src_contents, line_length=line_length)
     if src_contents == dst_contents:
-        raise NothingChanged(src)
+        raise NothingChanged
 
     if not fast:
         assert_equivalent(src_contents, dst_contents)
         assert_stable(src_contents, dst_contents, line_length=line_length)
-    return dst_contents, src_buffer.encoding
+    return dst_contents
 
 
 def format_str(src_contents: str, line_length: int) -> FileContent:
@@ -210,8 +238,13 @@ def format_str(src_contents: str, line_length: int) -> FileContent:
                 dst_contents += str(line)
         else:
             comments.append(current_line)
-    for comment in comments:
-        dst_contents += str(comment)
+    if comments:
+        if elt.previous_defs:
+            # Separate postscriptum comments from the last module-level def.
+            dst_contents += str(empty_line)
+            dst_contents += str(empty_line)
+        for comment in comments:
+            dst_contents += str(comment)
     return dst_contents
 
 
@@ -458,8 +491,7 @@ class Line:
         return (
             (first_leaf.type == token.NAME and first_leaf.value == 'def')
             or (
-                first_leaf.type == token.NAME
-                and first_leaf.value == 'async'
+                first_leaf.type == token.ASYNC
                 and second_leaf is not None
                 and second_leaf.type == token.NAME
                 and second_leaf.value == 'def'
@@ -615,7 +647,9 @@ class EmptyLineTracker:
     """Provides a stateful method that returns the number of potential extra
     empty lines needed before and after the currently processed line.
 
-    Note: this tracker works on lines that haven't been split yet.
+    Note: this tracker works on lines that haven't been split yet.  It assumes
+    the prefix of the first leaf consists of optional newlines.  Those newlines
+    are consumed by `maybe_empty_lines()` and included in the computation.
     """
     previous_line: Optional[Line] = None
     previous_after: int = 0
@@ -628,17 +662,28 @@ class EmptyLineTracker:
         (two on module-level), as well as providing an extra empty line after flow
         control keywords to make them more prominent.
         """
+        if current_line.is_comment:
+            # Don't count standalone comments towards previous empty lines.
+            return 0, 0
+
         before, after = self._maybe_empty_lines(current_line)
+        before -= self.previous_after
         self.previous_after = after
         self.previous_line = current_line
         return before, after
 
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
-        before = 0
+        if current_line.leaves:
+            # Consume the first leaf's extra newlines.
+            first_leaf = current_line.leaves[0]
+            before = int('\n' in first_leaf.prefix)
+            first_leaf.prefix = ''
+        else:
+            before = 0
         depth = current_line.depth
         while self.previous_defs and self.previous_defs[-1] >= depth:
             self.previous_defs.pop()
-            before = (1 if depth else 2) - self.previous_after
+            before = 1 if depth else 2
         is_decorator = current_line.is_decorator
         if is_decorator or current_line.is_def or current_line.is_class:
             if not is_decorator:
@@ -654,7 +699,6 @@ class EmptyLineTracker:
             newlines = 2
             if current_line.depth:
                 newlines -= 1
-            newlines -= self.previous_after
             return newlines, 0
 
         if current_line.is_flow_control:
@@ -706,8 +750,9 @@ class LineGenerator(Visitor[Line]):
 
     def visit_default(self, node: LN) -> Iterator[Line]:
         if isinstance(node, Leaf):
+            any_open_brackets = self.current_line.bracket_tracker.any_open_brackets()
             for comment in generate_comments(node):
-                if self.current_line.bracket_tracker.any_open_brackets():
+                if any_open_brackets:
                     # any comment within brackets is subject to splitting
                     self.current_line.append(comment)
                 elif comment.type == token.COMMENT:
@@ -719,7 +764,7 @@ class LineGenerator(Visitor[Line]):
                     # regular standalone comment, to be processed later (see
                     # docstring in `generate_comments()`
                     self.standalone_comments.append(comment)
-            normalize_prefix(node)
+            normalize_prefix(node, inside_brackets=any_open_brackets)
             if node.type not in WHITESPACE:
                 for comment in self.standalone_comments:
                     yield from self.line()
@@ -776,7 +821,7 @@ class LineGenerator(Visitor[Line]):
         for child in children:
             yield from self.visit(child)
 
-            if child.type == token.NAME and child.value == 'async':  # type: ignore
+            if child.type == token.ASYNC:
                 break
 
         internal_stmt = next(children)
@@ -814,7 +859,7 @@ BRACKET = {token.LPAR: token.RPAR, token.LSQB: token.RSQB, token.LBRACE: token.R
 OPENING_BRACKETS = set(BRACKET.keys())
 CLOSING_BRACKETS = set(BRACKET.values())
 BRACKETS = OPENING_BRACKETS | CLOSING_BRACKETS
-ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, token.COLON, STANDALONE_COMMENT}
+ALWAYS_NO_SPACE = CLOSING_BRACKETS | {token.COMMA, STANDALONE_COMMENT}
 
 
 def whitespace(leaf: Leaf) -> str:  # noqa C901
@@ -832,12 +877,18 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
         return DOUBLESPACE
 
     assert p is not None, f"INTERNAL ERROR: hand-made leaf without parent: {leaf!r}"
+    if t == token.COLON and p.type not in {syms.subscript, syms.subscriptlist}:
+        return NO
+
     prev = leaf.prev_sibling
     if not prev:
         prevp = preceding_leaf(p)
         if not prevp or prevp.type in OPENING_BRACKETS:
             return NO
 
+        if t == token.COLON:
+            return SPACE if prevp.type == token.COMMA else NO
+
         if prevp.type == token.EQUAL:
             if prevp.parent and prevp.parent.type in {
                 syms.typedargslist,
@@ -859,7 +910,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
                 return NO
 
         elif prevp.type == token.COLON:
-            if prevp.parent and prevp.parent.type == syms.subscript:
+            if prevp.parent and prevp.parent.type in {syms.subscript, syms.sliceop}:
                 return NO
 
         elif prevp.parent and prevp.parent.type in {syms.factor, syms.star_expr}:
@@ -966,7 +1017,7 @@ def whitespace(leaf: Leaf) -> str:  # noqa C901
 
             return NO
 
-        elif prev.type == token.COLON:
+        else:
             return NO
 
     elif p.type == syms.atom:
@@ -1098,7 +1149,7 @@ def generate_comments(leaf: Leaf) -> Iterator[Leaf]:
     if content and (content[0] not in {' ', '!', '#'}):
         content = ' ' + content
     is_standalone_comment = (
-        '\n' in before_comment or '\n' in content or leaf.type == token.DEDENT
+        '\n' in before_comment or '\n' in content or leaf.type == token.ENDMARKER
     )
     if not is_standalone_comment:
         # simple trailing comment
@@ -1193,7 +1244,7 @@ def left_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
                 current_leaves = body_leaves
     # Since body is a new indent level, remove spurious leading whitespace.
     if body_leaves:
-        normalize_prefix(body_leaves[0])
+        normalize_prefix(body_leaves[0], inside_brackets=True)
     # Build the new lines.
     for result, leaves in (
         (head, head_leaves), (body, body_leaves), (tail, tail_leaves)
@@ -1233,7 +1284,7 @@ def right_hand_split(line: Line, py36: bool = False) -> Iterator[Line]:
     head_leaves.reverse()
     # Since body is a new indent level, remove spurious leading whitespace.
     if body_leaves:
-        normalize_prefix(body_leaves[0])
+        normalize_prefix(body_leaves[0], inside_brackets=True)
     # Build the new lines.
     for result, leaves in (
         (head, head_leaves), (body, body_leaves), (tail, tail_leaves)
@@ -1297,7 +1348,7 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]:
             trailing_comma_safe = trailing_comma_safe and py36
         leaf_priority = delimiters.get(id(leaf))
         if leaf_priority == delimiter_priority:
-            normalize_prefix(current_line.leaves[0])
+            normalize_prefix(current_line.leaves[0], inside_brackets=True)
             yield current_line
 
             current_line = Line(depth=line.depth, inside_brackets=line.inside_brackets)
@@ -1308,7 +1359,7 @@ def delimiter_split(line: Line, py36: bool = False) -> Iterator[Line]:
             and trailing_comma_safe
         ):
             current_line.append(Leaf(token.COMMA, ','))
-        normalize_prefix(current_line.leaves[0])
+        normalize_prefix(current_line.leaves[0], inside_brackets=True)
         yield current_line
 
 
@@ -1326,16 +1377,18 @@ def is_import(leaf: Leaf) -> bool:
     )
 
 
-def normalize_prefix(leaf: Leaf) -> None:
-    """Leave existing extra newlines for imports.  Remove everything else."""
-    if is_import(leaf):
+def normalize_prefix(leaf: Leaf, *, inside_brackets: bool) -> None:
+    """Leave existing extra newlines if not `inside_brackets`.
+
+    Remove everything else.  Note: don't use backslashes for formatting or
+    you'll lose your voting rights.
+    """
+    if not inside_brackets:
         spl = leaf.prefix.split('#', 1)
-        nl_count = spl[0].count('\n')
-        if len(spl) > 1:
-            # Skip one newline since it was for a standalone comment.
-            nl_count -= 1
-        leaf.prefix = '\n' * nl_count
-        return
+        if '\\' not in spl[0]:
+            nl_count = spl[0].count('\n')
+            leaf.prefix = '\n' * nl_count
+            return
 
     leaf.prefix = ''