Don't use optional parentheses in unnecessary situations

[etc/vim.git] / black.py

diff --git a/black.py b/black.py
index 7823ae0afe2e809bdb2f5ca208ec9cc0565b4ced..e7a7aa8585836c72a5d24dfa35fda0089462578a 100644 (file)
--- a/black.py
+++ b/black.py
@@ -239,11 +239,8 @@ def reformat_one(
                 src = src.resolve()
                 if src in cache and cache[src] == get_cache_info(src):
                     changed = Changed.CACHED
                 src = src.resolve()
                 if src in cache and cache[src] == get_cache_info(src):
                     changed = Changed.CACHED

-            if (
-                changed is not Changed.CACHED
-                and format_file_in_place(
-                    src, line_length=line_length, fast=fast, write_back=write_back
-                )
+            if changed is not Changed.CACHED and format_file_in_place(
+                src, line_length=line_length, fast=fast, write_back=write_back

             ):
                 changed = Changed.YES
             if write_back == WriteBack.YES and changed is not Changed.NO:
             ):
                 changed = Changed.YES
             if write_back == WriteBack.YES and changed is not Changed.NO:


@@ -329,12 +326,13 @@ def format_file_in_place(
     If `write_back` is True, write reformatted code back to stdout.
     `line_length` and `fast` options are passed to :func:`format_file_contents`.
     """
     If `write_back` is True, write reformatted code back to stdout.
     `line_length` and `fast` options are passed to :func:`format_file_contents`.
     """

+    is_pyi = src.suffix == ".pyi"

 
     with tokenize.open(src) as src_buffer:
         src_contents = src_buffer.read()
     try:
         dst_contents = format_file_contents(
 
     with tokenize.open(src) as src_buffer:
         src_contents = src_buffer.read()
     try:
         dst_contents = format_file_contents(

-            src_contents, line_length=line_length, fast=fast
+            src_contents, line_length=line_length, fast=fast, is_pyi=is_pyi

         )
     except NothingChanged:
         return False
         )
     except NothingChanged:
         return False


@@ -383,7 +381,7 @@ def format_stdin_to_stdout(
 
 
 def format_file_contents(
 
 
 def format_file_contents(

-    src_contents: str, line_length: int, fast: bool
+    src_contents: str, *, line_length: int, fast: bool, is_pyi: bool = False

 ) -> FileContent:
     """Reformat contents a file and return new contents.
 
 ) -> FileContent:
     """Reformat contents a file and return new contents.
 


@@ -394,17 +392,21 @@ def format_file_contents(
     if src_contents.strip() == "":
         raise NothingChanged
 
     if src_contents.strip() == "":
         raise NothingChanged
 

-    dst_contents = format_str(src_contents, line_length=line_length)
+    dst_contents = format_str(src_contents, line_length=line_length, is_pyi=is_pyi)

     if src_contents == dst_contents:
         raise NothingChanged
 
     if not fast:
         assert_equivalent(src_contents, dst_contents)
     if src_contents == dst_contents:
         raise NothingChanged
 
     if not fast:
         assert_equivalent(src_contents, dst_contents)

-        assert_stable(src_contents, dst_contents, line_length=line_length)
+        assert_stable(
+            src_contents, dst_contents, line_length=line_length, is_pyi=is_pyi
+        )

     return dst_contents
 
 
     return dst_contents
 
 

-def format_str(src_contents: str, line_length: int) -> FileContent:
+def format_str(
+    src_contents: str, line_length: int, *, is_pyi: bool = False
+) -> FileContent:

     """Reformat a string and return new contents.
 
     `line_length` determines how many characters per line are allowed.
     """Reformat a string and return new contents.
 
     `line_length` determines how many characters per line are allowed.


@@ -412,9 +414,11 @@ def format_str(src_contents: str, line_length: int) -> FileContent:
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""
     future_imports = get_future_imports(src_node)
     src_node = lib2to3_parse(src_contents)
     dst_contents = ""
     future_imports = get_future_imports(src_node)

+    elt = EmptyLineTracker(is_pyi=is_pyi)

     py36 = is_python36(src_node)
     py36 = is_python36(src_node)

-    lines = LineGenerator(remove_u_prefix=py36 or "unicode_literals" in future_imports)
-    elt = EmptyLineTracker()
+    lines = LineGenerator(
+        remove_u_prefix=py36 or "unicode_literals" in future_imports, is_pyi=is_pyi
+    )

     empty_line = Line()
     after = 0
     for current_line in lines.visit(src_node):
     empty_line = Line()
     after = 0
     for current_line in lines.visit(src_node):


@@ -833,6 +837,14 @@ class Line:
             and self.leaves[0].value == "class"
         )
 
             and self.leaves[0].value == "class"
         )
 

+    @property
+    def is_stub_class(self) -> bool:
+        """Is this line a class definition with a body consisting only of "..."?"""
+        return (
+            self.is_class
+            and self.leaves[-3:] == [Leaf(token.DOT, ".") for _ in range(3)]
+        )
+

     @property
     def is_def(self) -> bool:
         """Is this a function definition? (Also returns True for async defs.)"""
     @property
     def is_def(self) -> bool:
         """Is this a function definition? (Also returns True for async defs.)"""


@@ -845,14 +857,11 @@ class Line:
             second_leaf: Optional[Leaf] = self.leaves[1]
         except IndexError:
             second_leaf = None
             second_leaf: Optional[Leaf] = self.leaves[1]
         except IndexError:
             second_leaf = None

-        return (
-            (first_leaf.type == token.NAME and first_leaf.value == "def")
-            or (
-                first_leaf.type == token.ASYNC
-                and second_leaf is not None
-                and second_leaf.type == token.NAME
-                and second_leaf.value == "def"
-            )
+        return (first_leaf.type == token.NAME and first_leaf.value == "def") or (
+            first_leaf.type == token.ASYNC
+            and second_leaf is not None
+            and second_leaf.type == token.NAME
+            and second_leaf.value == "def"

         )
 
     @property
         )
 
     @property


@@ -1017,9 +1026,8 @@ class Line:
             and subscript_start.type == syms.subscriptlist
         ):
             subscript_start = child_towards(subscript_start, leaf)
             and subscript_start.type == syms.subscriptlist
         ):
             subscript_start = child_towards(subscript_start, leaf)

-        return (
-            subscript_start is not None
-            and any(n.type in TEST_DESCENDANTS for n in subscript_start.pre_order())
+        return subscript_start is not None and any(
+            n.type in TEST_DESCENDANTS for n in subscript_start.pre_order()

         )
 
     def __str__(self) -> str:
         )
 
     def __str__(self) -> str:


@@ -1100,6 +1108,7 @@ class EmptyLineTracker:
     the prefix of the first leaf consists of optional newlines.  Those newlines
     are consumed by `maybe_empty_lines()` and included in the computation.
     """
     the prefix of the first leaf consists of optional newlines.  Those newlines
     are consumed by `maybe_empty_lines()` and included in the computation.
     """

+    is_pyi: bool = False

     previous_line: Optional[Line] = None
     previous_after: int = 0
     previous_defs: List[int] = Factory(list)
     previous_line: Optional[Line] = None
     previous_after: int = 0
     previous_defs: List[int] = Factory(list)


@@ -1123,7 +1132,7 @@ class EmptyLineTracker:
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
         max_allowed = 1
         if current_line.depth == 0:
     def _maybe_empty_lines(self, current_line: Line) -> Tuple[int, int]:
         max_allowed = 1
         if current_line.depth == 0:

-            max_allowed = 2
+            max_allowed = 1 if self.is_pyi else 2

         if current_line.leaves:
             # Consume the first leaf's extra newlines.
             first_leaf = current_line.leaves[0]
         if current_line.leaves:
             # Consume the first leaf's extra newlines.
             first_leaf = current_line.leaves[0]


@@ -1135,7 +1144,10 @@ class EmptyLineTracker:
         depth = current_line.depth
         while self.previous_defs and self.previous_defs[-1] >= depth:
             self.previous_defs.pop()
         depth = current_line.depth
         while self.previous_defs and self.previous_defs[-1] >= depth:
             self.previous_defs.pop()

-            before = 1 if depth else 2
+            if self.is_pyi:
+                before = 0 if depth else 1
+            else:
+                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:
         is_decorator = current_line.is_decorator
         if is_decorator or current_line.is_def or current_line.is_class:
             if not is_decorator:


@@ -1154,8 +1166,19 @@ class EmptyLineTracker:
             ):
                 return 0, 0
 
             ):
                 return 0, 0
 

-            newlines = 2
-            if current_line.depth:
+            if self.is_pyi:
+                if self.previous_line.depth > current_line.depth:
+                    newlines = 1
+                elif current_line.is_class or self.previous_line.is_class:
+                    if current_line.is_stub_class and self.previous_line.is_stub_class:
+                        newlines = 0
+                    else:
+                        newlines = 1
+                else:
+                    newlines = 0
+            else:
+                newlines = 2
+            if current_line.depth and newlines:

                 newlines -= 1
             return newlines, 0
 
                 newlines -= 1
             return newlines, 0
 


@@ -1177,6 +1200,7 @@ class LineGenerator(Visitor[Line]):
     Note: destroys the tree it's visiting by mutating prefixes of its leaves
     in ways that will no longer stringify to valid Python code on the tree.
     """
     Note: destroys the tree it's visiting by mutating prefixes of its leaves
     in ways that will no longer stringify to valid Python code on the tree.
     """

+    is_pyi: bool = False

     current_line: Line = Factory(Line)
     remove_u_prefix: bool = False
 
     current_line: Line = Factory(Line)
     remove_u_prefix: bool = False
 


@@ -1293,16 +1317,27 @@ class LineGenerator(Visitor[Line]):
 
             yield from self.visit(child)
 
 
             yield from self.visit(child)
 

+    def visit_suite(self, node: Node) -> Iterator[Line]:
+        """Visit a suite."""
+        if self.is_pyi and is_stub_suite(node):
+            yield from self.visit(node.children[2])
+        else:
+            yield from self.visit_default(node)
+

     def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
         """Visit a statement without nested statements."""
         is_suite_like = node.parent and node.parent.type in STATEMENT
         if is_suite_like:
     def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
         """Visit a statement without nested statements."""
         is_suite_like = node.parent and node.parent.type in STATEMENT
         if is_suite_like:

-            yield from self.line(+1)
-            yield from self.visit_default(node)
-            yield from self.line(-1)
+            if self.is_pyi and is_stub_body(node):
+                yield from self.visit_default(node)
+            else:
+                yield from self.line(+1)
+                yield from self.visit_default(node)
+                yield from self.line(-1)

 
         else:
 
         else:

-            yield from self.line()
+            if not self.is_pyi or not node.parent or not is_stub_suite(node.parent):
+                yield from self.line()

             yield from self.visit_default(node)
 
     def visit_async_stmt(self, node: Node) -> Iterator[Line]:
             yield from self.visit_default(node)
 
     def visit_async_stmt(self, node: Node) -> Iterator[Line]:


@@ -1929,6 +1964,8 @@ def right_hand_split(
     If the split was by optional parentheses, attempt splitting without them, too.
     `omit` is a collection of closing bracket IDs that shouldn't be considered for
     this split.
     If the split was by optional parentheses, attempt splitting without them, too.
     `omit` is a collection of closing bracket IDs that shouldn't be considered for
     this split.

+
+    Note: running this function modifies `bracket_depth` on the leaves of `line`.

     """
     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)
     """
     head = Line(depth=line.depth)
     body = Line(depth=line.depth + 1, inside_brackets=True)


@@ -1955,8 +1992,9 @@ def right_hand_split(
     # Since body is a new indent level, remove spurious leading whitespace.
     if body_leaves:
         normalize_prefix(body_leaves[0], inside_brackets=True)
     # Since body is a new indent level, remove spurious leading whitespace.
     if body_leaves:
         normalize_prefix(body_leaves[0], inside_brackets=True)

-    elif not head_leaves:
-        # No `head` and no `body` means the split failed. `tail` has all content.
+    if not head_leaves:
+        # No `head` means the split failed. Either `tail` has all content or
+        # the matching `opening_bracket` wasn't available on `line` anymore.

         raise CannotSplit("No brackets found")
 
     # Build the new lines.
         raise CannotSplit("No brackets found")
 
     # Build the new lines.


@@ -1974,19 +2012,27 @@ def right_hand_split(
         # the closing bracket is an optional paren
         and closing_bracket.type == token.RPAR
         and not closing_bracket.value
         # the closing bracket is an optional paren
         and closing_bracket.type == token.RPAR
         and not closing_bracket.value

-        # there are no delimiters or standalone comments in the body
-        and not body.bracket_tracker.delimiters
+        # there are no standalone comments in the body

         and not line.contains_standalone_comments(0)
         # and it's not an import (optional parens are the only thing we can split
         # on in this case; attempting a split without them is a waste of time)
         and not line.is_import
     ):
         omit = {id(closing_bracket), *omit}
         and not line.contains_standalone_comments(0)
         # and it's not an import (optional parens are the only thing we can split
         # on in this case; attempting a split without them is a waste of time)
         and not line.is_import
     ):
         omit = {id(closing_bracket), *omit}

-        try:
-            yield from right_hand_split(line, py36=py36, omit=omit)
-            return
-        except CannotSplit:
-            pass
+        delimiter_count = len(body.bracket_tracker.delimiters)
+        if (
+            delimiter_count == 0
+            or delimiter_count == 1
+            and (
+                body.leaves[0].type in OPENING_BRACKETS
+                or body.leaves[-1].type in CLOSING_BRACKETS
+            )
+        ):
+            try:
+                yield from right_hand_split(line, py36=py36, omit=omit)
+                return
+            except CannotSplit:
+                pass

 
     ensure_visible(opening_bracket)
     ensure_visible(closing_bracket)
 
     ensure_visible(opening_bracket)
     ensure_visible(closing_bracket)


@@ -2388,6 +2434,35 @@ def is_vararg(leaf: Leaf, within: Set[NodeType]) -> bool:
     return p.type in within
 
 
     return p.type in within
 
 

+def is_stub_suite(node: Node) -> bool:
+    """Return True if `node` is a suite with a stub body."""
+    if (
+        len(node.children) != 4
+        or node.children[0].type != token.NEWLINE
+        or node.children[1].type != token.INDENT
+        or node.children[3].type != token.DEDENT
+    ):
+        return False
+
+    return is_stub_body(node.children[2])
+
+
+def is_stub_body(node: LN) -> bool:
+    """Return True if `node` is a simple statement containing an ellipsis."""
+    if not isinstance(node, Node) or node.type != syms.simple_stmt:
+        return False
+
+    if len(node.children) != 2:
+        return False
+
+    child = node.children[0]
+    return (
+        child.type == syms.atom
+        and len(child.children) == 3
+        and all(leaf == Leaf(token.DOT, ".") for leaf in child.children)
+    )
+
+

 def max_delimiter_priority_in_atom(node: LN) -> int:
     """Return maximum delimiter priority inside `node`.
 
 def max_delimiter_priority_in_atom(node: LN) -> int:
     """Return maximum delimiter priority inside `node`.
 


@@ -2554,7 +2629,7 @@ def get_future_imports(node: Node) -> Set[str]:
     return imports
 
 
     return imports
 
 

-PYTHON_EXTENSIONS = {".py"}
+PYTHON_EXTENSIONS = {".py", ".pyi"}

 BLACKLISTED_DIRECTORIES = {
     "build", "buck-out", "dist", "_build", ".git", ".hg", ".mypy_cache", ".tox", ".venv"
 }
 BLACKLISTED_DIRECTORIES = {
     "build", "buck-out", "dist", "_build", ".git", ".hg", ".mypy_cache", ".tox", ".venv"
 }


@@ -2717,9 +2792,9 @@ def assert_equivalent(src: str, dst: str) -> None:
         ) from None
 
 
         ) from None
 
 

-def assert_stable(src: str, dst: str, line_length: int) -> None:
+def assert_stable(src: str, dst: str, line_length: int, is_pyi: bool = False) -> None:

     """Raise AssertionError if `dst` reformats differently the second time."""
     """Raise AssertionError if `dst` reformats differently the second time."""

-    newdst = format_str(dst, line_length=line_length)
+    newdst = format_str(dst, line_length=line_length, is_pyi=is_pyi)

     if dst != newdst:
         log = dump_to_file(
             diff(src, dst, "source", "first pass"),
     if dst != newdst:
         log = dump_to_file(
             diff(src, dst, "source", "first pass"),