]> git.madduck.net Git - etc/vim.git/blobdiff - black.py

madduck's git repository

Every one of the projects in this repository is available at the canonical URL git://git.madduck.net/madduck/pub/<projectpath> — see each project's metadata for the exact URL.

All patches and comments are welcome. Please squash your changes to logical commits before using git-format-patch and git-send-email to patches@git.madduck.net. If you'd read over the Git project's submission guidelines and adhered to them, I'd be especially grateful.

SSH access, as well as push access can be individually arranged.

If you use my repositories frequently, consider adding the following snippet to ~/.gitconfig and using the third clone URL listed for each project:

[url "git://git.madduck.net/madduck/"]
  insteadOf = madduck:

Add link to the pyproject.toml for setting up pre-commit hook (#885)
[etc/vim.git] / black.py
index 1978fd52ec91969e226908ebb566d18f422a3ab7..635eba207cd0c2a695cab27d68326216a90325f5 100644 (file)
--- a/black.py
+++ b/black.py
@@ -16,6 +16,7 @@ import signal
 import sys
 import tempfile
 import tokenize
+import traceback
 from typing import (
     Any,
     Callable,
@@ -40,6 +41,7 @@ from appdirs import user_cache_dir
 from attr import dataclass, evolve, Factory
 import click
 import toml
+from typed_ast import ast3, ast27
 
 # lib2to3 fork
 from blib2to3.pytree import Node, Leaf, type_repr
@@ -135,19 +137,28 @@ class Feature(Enum):
     NUMERIC_UNDERSCORES = 3
     TRAILING_COMMA_IN_CALL = 4
     TRAILING_COMMA_IN_DEF = 5
+    # The following two feature-flags are mutually exclusive, and exactly one should be
+    # set for every version of python.
+    ASYNC_IDENTIFIERS = 6
+    ASYNC_KEYWORDS = 7
 
 
 VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
-    TargetVersion.PY27: set(),
-    TargetVersion.PY33: {Feature.UNICODE_LITERALS},
-    TargetVersion.PY34: {Feature.UNICODE_LITERALS},
-    TargetVersion.PY35: {Feature.UNICODE_LITERALS, Feature.TRAILING_COMMA_IN_CALL},
+    TargetVersion.PY27: {Feature.ASYNC_IDENTIFIERS},
+    TargetVersion.PY33: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+    TargetVersion.PY34: {Feature.UNICODE_LITERALS, Feature.ASYNC_IDENTIFIERS},
+    TargetVersion.PY35: {
+        Feature.UNICODE_LITERALS,
+        Feature.TRAILING_COMMA_IN_CALL,
+        Feature.ASYNC_IDENTIFIERS,
+    },
     TargetVersion.PY36: {
         Feature.UNICODE_LITERALS,
         Feature.F_STRINGS,
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
+        Feature.ASYNC_IDENTIFIERS,
     },
     TargetVersion.PY37: {
         Feature.UNICODE_LITERALS,
@@ -155,6 +166,7 @@ VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
+        Feature.ASYNC_KEYWORDS,
     },
     TargetVersion.PY38: {
         Feature.UNICODE_LITERALS,
@@ -162,6 +174,7 @@ VERSION_TO_FEATURES: Dict[TargetVersion, Set[Feature]] = {
         Feature.NUMERIC_UNDERSCORES,
         Feature.TRAILING_COMMA_IN_CALL,
         Feature.TRAILING_COMMA_IN_DEF,
+        Feature.ASYNC_KEYWORDS,
     },
 }
 
@@ -324,7 +337,7 @@ def read_pyproject_toml(
     "--quiet",
     is_flag=True,
     help=(
-        "Don't emit non-error messages to stderr. Errors are still emitted, "
+        "Don't emit non-error messages to stderr. Errors are still emitted; "
         "silence those with 2>/dev/null."
     ),
 )
@@ -445,8 +458,7 @@ def main(
         )
 
     if verbose or not quiet:
-        bang = "💥 💔 💥" if report.return_code else "✨ 🍰 ✨"
-        out(f"All done! {bang}")
+        out("Oh no! 💥 💔 💥" if report.return_code else "All done! ✨ 🍰 ✨")
         click.secho(str(report), err=True)
     ctx.exit(report.return_code)
 
@@ -456,8 +468,7 @@ def reformat_one(
 ) -> None:
     """Reformat a single file under `src` without spawning child processes.
 
-    If `quiet` is True, non-error messages are not output. `line_length`,
-    `write_back`, `fast` and `pyi` options are passed to
+    `fast`, `write_back`, and `mode` options are passed to
     :func:`format_file_in_place` or :func:`format_stdin_to_stdout`.
     """
     try:
@@ -597,7 +608,7 @@ def format_file_in_place(
 
     If `write_back` is DIFF, write a diff to stdout. If it is YES, write reformatted
     code to the file.
-    `line_length` and `fast` options are passed to :func:`format_file_contents`.
+    `mode` and `fast` options are passed to :func:`format_file_contents`.
     """
     if src.suffix == ".pyi":
         mode = evolve(mode, is_pyi=True)
@@ -675,7 +686,7 @@ def format_file_contents(
 
     If `fast` is False, additionally confirm that the reformatted code is
     valid by calling :func:`assert_equivalent` and :func:`assert_stable` on it.
-    `line_length` is passed to :func:`format_str`.
+    `mode` is passed to :func:`format_str`.
     """
     if src_contents.strip() == "":
         raise NothingChanged
@@ -693,10 +704,11 @@ def format_file_contents(
 def format_str(src_contents: str, *, mode: FileMode) -> FileContent:
     """Reformat a string and return new contents.
 
-    `line_length` determines how many characters per line are allowed.
+    `mode` determines formatting options, such as how many characters per line are
+    allowed.
     """
     src_node = lib2to3_parse(src_contents.lstrip(), mode.target_versions)
-    dst_contents = ""
+    dst_contents = []
     future_imports = get_future_imports(src_node)
     if mode.target_versions:
         versions = mode.target_versions
@@ -719,15 +731,15 @@ def format_str(src_contents: str, *, mode: FileMode) -> FileContent:
     }
     for current_line in lines.visit(src_node):
         for _ in range(after):
-            dst_contents += str(empty_line)
+            dst_contents.append(str(empty_line))
         before, after = elt.maybe_empty_lines(current_line)
         for _ in range(before):
-            dst_contents += str(empty_line)
+            dst_contents.append(str(empty_line))
         for line in split_line(
             current_line, line_length=mode.line_length, features=split_line_features
         ):
-            dst_contents += str(line)
-    return dst_contents
+            dst_contents.append(str(line))
+    return "".join(dst_contents)
 
 
 def decode_bytes(src: bytes) -> Tuple[FileContent, Encoding, NewLine]:
@@ -751,16 +763,38 @@ def get_grammars(target_versions: Set[TargetVersion]) -> List[Grammar]:
     if not target_versions:
         # No target_version specified, so try all grammars.
         return [
+            # Python 3.7+
+            pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords,
+            # Python 3.0-3.6
             pygram.python_grammar_no_print_statement_no_exec_statement,
+            # Python 2.7 with future print_function import
             pygram.python_grammar_no_print_statement,
+            # Python 2.7
             pygram.python_grammar,
         ]
     elif all(version.is_python2() for version in target_versions):
         # Python 2-only code, so try Python 2 grammars.
-        return [pygram.python_grammar_no_print_statement, pygram.python_grammar]
+        return [
+            # Python 2.7 with future print_function import
+            pygram.python_grammar_no_print_statement,
+            # Python 2.7
+            pygram.python_grammar,
+        ]
     else:
         # Python 3-compatible code, so only try Python 3 grammar.
-        return [pygram.python_grammar_no_print_statement_no_exec_statement]
+        grammars = []
+        # If we have to parse both, try to parse async as a keyword first
+        if not supports_feature(target_versions, Feature.ASYNC_IDENTIFIERS):
+            # Python 3.7+
+            grammars.append(
+                pygram.python_grammar_no_print_statement_no_exec_statement_async_keywords  # noqa: B950
+            )
+        if not supports_feature(target_versions, Feature.ASYNC_KEYWORDS):
+            # Python 3.0-3.6
+            grammars.append(pygram.python_grammar_no_print_statement_no_exec_statement)
+        # At least one of the above branches must have been taken, because every Python
+        # version has exactly one of the two 'ASYNC_*' flags
+        return grammars
 
 
 def lib2to3_parse(src_txt: str, target_versions: Iterable[TargetVersion] = ()) -> Node:
@@ -1027,7 +1061,7 @@ class BracketTracker:
         """Return True if there is an yet unmatched open bracket on the line."""
         return bool(self.bracket_match)
 
-    def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> int:
+    def max_delimiter_priority(self, exclude: Iterable[LeafID] = ()) -> Priority:
         """Return the highest priority of a delimiter found on the line.
 
         Values are consistent with what `is_split_*_delimiter()` return.
@@ -1035,7 +1069,7 @@ class BracketTracker:
         """
         return max(v for k, v in self.delimiters.items() if k not in exclude)
 
-    def delimiter_count_with_priority(self, priority: int = 0) -> int:
+    def delimiter_count_with_priority(self, priority: Priority = 0) -> int:
         """Return the number of delimiters with the given `priority`.
 
         If no `priority` is passed, defaults to max priority on the line.
@@ -1568,6 +1602,26 @@ class LineGenerator(Visitor[Line]):
                 self.current_line.append(node)
         yield from super().visit_default(node)
 
+    def visit_atom(self, node: Node) -> Iterator[Line]:
+        # Always make parentheses invisible around a single node, because it should
+        # not be needed (except in the case of yield, where removing the parentheses
+        # produces a SyntaxError).
+        if (
+            len(node.children) == 3
+            and isinstance(node.children[0], Leaf)
+            and node.children[0].type == token.LPAR
+            and isinstance(node.children[2], Leaf)
+            and node.children[2].type == token.RPAR
+            and isinstance(node.children[1], Leaf)
+            and not (
+                node.children[1].type == token.NAME
+                and node.children[1].value == "yield"
+            )
+        ):
+            node.children[0].value = ""
+            node.children[2].value = ""
+        yield from super().visit_default(node)
+
     def visit_INDENT(self, node: Node) -> Iterator[Line]:
         """Increase indentation level, maybe yield a line."""
         # In blib2to3 INDENT never holds comments.
@@ -1981,7 +2035,7 @@ def container_of(leaf: Leaf) -> LN:
     return container
 
 
-def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int:
+def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
     """Return the priority of the `leaf` delimiter, given a line break after it.
 
     The delimiter priorities returned here are from those delimiters that would
@@ -1995,7 +2049,7 @@ def is_split_after_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int
     return 0
 
 
-def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> int:
+def is_split_before_delimiter(leaf: Leaf, previous: Optional[Leaf] = None) -> Priority:
     """Return the priority of the `leaf` delimiter, given a line break before it.
 
     The delimiter priorities returned here are from those delimiters that would
@@ -2675,7 +2729,15 @@ def normalize_string_quotes(leaf: Leaf) -> None:
         new_body = sub_twice(escaped_orig_quote, rf"\1\2{orig_quote}", new_body)
         new_body = sub_twice(unescaped_new_quote, rf"\1\\{new_quote}", new_body)
     if "f" in prefix.casefold():
-        matches = re.findall(r"[^{]\{(.*?)\}[^}]", new_body)
+        matches = re.findall(
+            r"""
+            (?:[^{]|^)\{  # start of the string or a non-{ followed by a single {
+                ([^{].*?)  # contents of the brackets except if begins with {{
+            \}(?:[^}]|$)  # A } followed by end of the string or a non-}
+            """,
+            new_body,
+            re.VERBOSE,
+        )
         for m in matches:
             if "\\" in str(m):
                 # Do not introduce backslashes in interpolated expressions
@@ -2742,7 +2804,7 @@ def format_float_or_int_string(text: str) -> str:
 def normalize_invisible_parens(node: Node, parens_after: Set[str]) -> None:
     """Make existing optional parentheses invisible or create new ones.
 
-    `parens_after` is a set of string leaf values immeditely after which parens
+    `parens_after` is a set of string leaf values immediately after which parens
     should be put.
 
     Standardizes on visible parentheses for single-element tuples, and keeps
@@ -3020,7 +3082,7 @@ def is_stub_body(node: LN) -> bool:
     )
 
 
-def max_delimiter_priority_in_atom(node: LN) -> int:
+def max_delimiter_priority_in_atom(node: LN) -> Priority:
     """Return maximum delimiter priority inside `node`.
 
     This is specific to atoms with contents contained in a pair of parentheses.
@@ -3380,17 +3442,32 @@ class Report:
         return ", ".join(report) + "."
 
 
+def parse_ast(src: str) -> Union[ast3.AST, ast27.AST]:
+    for feature_version in (7, 6):
+        try:
+            return ast3.parse(src, feature_version=feature_version)
+        except SyntaxError:
+            continue
+
+    return ast27.parse(src)
+
+
 def assert_equivalent(src: str, dst: str) -> None:
     """Raise AssertionError if `src` and `dst` aren't equivalent."""
 
-    import ast
-    import traceback
-
-    def _v(node: ast.AST, depth: int = 0) -> Iterator[str]:
+    def _v(node: Union[ast3.AST, ast27.AST], depth: int = 0) -> Iterator[str]:
         """Simple visitor generating strings to compare ASTs by content."""
         yield f"{'  ' * depth}{node.__class__.__name__}("
 
         for field in sorted(node._fields):
+            # TypeIgnore has only one field 'lineno' which breaks this comparison
+            if isinstance(node, (ast3.TypeIgnore, ast27.TypeIgnore)):
+                break
+
+            # Ignore str kind which is case sensitive / and ignores unicode_literals
+            if isinstance(node, (ast3.Str, ast27.Str, ast3.Bytes)) and field == "kind":
+                continue
+
             try:
                 value = getattr(node, field)
             except AttributeError:
@@ -3404,15 +3481,15 @@ def assert_equivalent(src: str, dst: str) -> None:
                     # parentheses and they change the AST.
                     if (
                         field == "targets"
-                        and isinstance(node, ast.Delete)
-                        and isinstance(item, ast.Tuple)
+                        and isinstance(node, (ast3.Delete, ast27.Delete))
+                        and isinstance(item, (ast3.Tuple, ast27.Tuple))
                     ):
                         for item in item.elts:
                             yield from _v(item, depth + 2)
-                    elif isinstance(item, ast.AST):
+                    elif isinstance(item, (ast3.AST, ast27.AST)):
                         yield from _v(item, depth + 2)
 
-            elif isinstance(value, ast.AST):
+            elif isinstance(value, (ast3.AST, ast27.AST)):
                 yield from _v(value, depth + 2)
 
             else:
@@ -3421,17 +3498,15 @@ def assert_equivalent(src: str, dst: str) -> None:
         yield f"{'  ' * depth})  # /{node.__class__.__name__}"
 
     try:
-        src_ast = ast.parse(src)
+        src_ast = parse_ast(src)
     except Exception as exc:
-        major, minor = sys.version_info[:2]
         raise AssertionError(
-            f"cannot use --safe with this file; failed to parse source file "
-            f"with Python {major}.{minor}'s builtin AST. Re-run with --fast "
-            f"or stop using deprecated Python 2 syntax. AST error message: {exc}"
+            f"cannot use --safe with this file; failed to parse source file.  "
+            f"AST error message: {exc}"
         )
 
     try:
-        dst_ast = ast.parse(dst)
+        dst_ast = parse_ast(dst)
     except Exception as exc:
         log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
         raise AssertionError(
@@ -3470,8 +3545,6 @@ def assert_stable(src: str, dst: str, mode: FileMode) -> None:
 
 def dump_to_file(*output: str) -> str:
     """Dump `output` to a temporary file. Return path to the file."""
-    import tempfile
-
     with tempfile.NamedTemporaryFile(
         mode="w", prefix="blk_", suffix=".log", delete=False, encoding="utf8"
     ) as f:
@@ -3569,7 +3642,6 @@ def enumerate_with_length(
         if "\n" in leaf.value:
             return  # Multiline strings, we can't continue.
 
-        comment: Optional[Leaf]
         for comment in line.comments_after(leaf):
             length += len(comment.value)