Merge branch 'feat/pyproject-config' of https://github.com/Shivansh-007/black into feat/pyproject-config

Author: Shivansh-007

CHANGES.md

@@ -2,41 +2,59 @@
 
 ## Unreleased
 
-### _Black_
+At long last, _Black_ is no longer a beta product! This is the first non-beta release
+and the first release covered by our new stability policy.
+
+### Highlights
 
 - **Remove Python 2 support** (#2740)
-- Do not accept bare carriage return line endings in pyproject.toml (#2408)
-- Improve error message for invalid regular expression (#2678)
-- Improve error message when parsing fails during AST safety check by embedding the
-  underlying SyntaxError (#2693)
+- Introduce the `--preview` flag (#2752)
+
+### Style
+
+- Deprecate `--experimental-string-processing` and move the functionality under
+  `--preview` (#2789)
+- For stubs, one blank line between class attributes and methods is now kept if there's
+  at least one pre-existing blank line (#2736)
+- Black now normalizes string prefix order (#2297)
+- Remove spaces around power operators if both operands are simple (#2726)
+- Work around bug that causes unstable formatting in some cases in the presence of the
+  magic trailing comma (#2807)
+- Use parentheses for attribute access on decimal float and int literals (#2799)
+- Don't add whitespace for attribute access on hexadecimal, binary, octal, and complex
+  literals (#2799)
+- Treat blank lines in stubs the same inside top-level `if` statements (#2820)
+- Fix unstable formatting with semicolons and arithmetic expressions (#2817)
+
+### Parser
+
 - Fix mapping cases that contain as-expressions, like `case {"key": 1 | 2 as password}`
   (#2686)
 - Fix cases that contain multiple top-level as-expressions, like `case 1 as a, 2 as b`
   (#2716)
 - Fix call patterns that contain as-expressions with keyword arguments, like
   `case Foo(bar=baz as quux)` (#2749)
-- No longer color diff headers white as it's unreadable in light themed terminals
-  (#2691)
 - Tuple unpacking on `return` and `yield` constructs now implies 3.8+ (#2700)
 - Unparenthesized tuples on annotated assignments (e.g
   `values: Tuple[int, ...] = 1, 2, 3`) now implies 3.8+ (#2708)
-- Remove spaces around power operators if both operands are simple (#2726)
-- Allow setting custom cache directory on all platforms with environment variable
-  `BLACK_CACHE_DIR` (#2739).
-- Text coloring added in the final statistics (#2712)
-- For stubs, one blank line between class attributes and methods is now kept if there's
-  at least one pre-existing blank line (#2736)
-- Verbose mode also now describes how a project root was discovered and which paths will
-  be formatted. (#2526)
-- Speed-up the new backtracking parser about 4X in general (enabled when
-  `--target-version` is set to 3.10 and higher). (#2728)
 - Fix handling of standalone `match()` or `case()` when there is a trailing newline or a
   comment inside of the parentheses. (#2760)
-- Black now normalizes string prefix order (#2297)
+
+### Performance
+
+- Speed-up the new backtracking parser about 4X in general (enabled when
+  `--target-version` is set to 3.10 and higher). (#2728)
+- _Black_ is now compiled with [mypyc](https://github.com/mypyc/mypyc) for an overall 2x
+  speed-up. 64-bit Windows, MacOS, and Linux (not including musl) are supported. (#1009,
+  #2431)
+
+### Configuration
+
+- Do not accept bare carriage return line endings in pyproject.toml (#2408)
 - Add configuration option (`python-cell-magics`) to format cells with custom magics in
   Jupyter Notebooks (#2744)
-- Deprecate `--experimental-string-processing` and move the functionality under
-  `--preview` (#2789)
+- Allow setting custom cache directory on all platforms with environment variable
+  `BLACK_CACHE_DIR` (#2739).
 - Enable Python 3.10+ by default, without any extra need to specify
   `--target-version=py310`. (#2758)
 - Make passing `SRC` or `--code` mandatory and mutually exclusive (#2804)
@@ -48,17 +66,23 @@
 - Deprecate the `black-primer` tool (#2809)
 - Allow specifying `config` in config files to include configuration options (#2525)
 
+### Output
+
+- Improve error message for invalid regular expression (#2678)
+- Improve error message when parsing fails during AST safety check by embedding the
+  underlying SyntaxError (#2693)
+- No longer color diff headers white as it's unreadable in light themed terminals
+  (#2691)
+- Text coloring added in the final statistics (#2712)
+- Verbose mode also now describes how a project root was discovered and which paths will
+  be formatted. (#2526)
+
 ### Packaging
 
 - All upper version bounds on dependencies have been removed (#2718)
 - `typing-extensions` is no longer a required dependency in Python 3.10+ (#2772)
 - Set `click` lower bound to `8.0.0` (#2791)
 
-### Preview style
-
-- Introduce the `--preview` flag (#2752)
-- Add `--experimental-string-processing` to the preview style (#2789)
-
 ### Integrations
 
 - Update GitHub action to support containerized runs (#2748)
@@ -68,6 +92,8 @@
 - Change protocol in pip installation instructions to `https://` (#2761)
 - Change HTML theme to Furo primarily for its responsive design and mobile support
   (#2793)
+- Deprecate the `black-primer` tool (#2809)
+- Document Python support policy (#2819)
 
 ## 21.12b0
 
@@ -120,6 +146,7 @@
   when `--target-version py310` is explicitly specified (#2586)
 - Add support for parenthesized with (#2586)
 - Declare support for Python 3.10 for running Black (#2562)
+- Fix unstable black runs around magic trailing comma (#2572)
 
 ### Integrations
 

docs/faq.md

@@ -71,9 +71,16 @@ readability because operators are misaligned. Disable W503 and enable the
 disabled-by-default counterpart W504. E203 should be disabled while changes are still
 [discussed](https://github.com/PyCQA/pycodestyle/issues/373).
 
-## Does Black support Python 2?
+## Which Python versions does Black support?
 
-Support for formatting Python 2 code was removed in version 22.0.
+Currently the runtime requires Python 3.6-3.10. Formatting is supported for files
+containing syntax from Python 3.3 to 3.10. We promise to support at least all Python
+versions that have not reached their end of life. This is the case for both running
+_Black_ and formatting code.
+
+Support for formatting Python 2 code was removed in version 22.0. While we've made no
+plans to stop supporting older Python 3 minor versions immediately, their support might
+also be removed some time in the future without a deprecation period.
 
 ## Why does my linter or typechecker complain after I format my code?
 

docs/the_black_code_style/current_style.md

@@ -2,10 +2,14 @@
 
 ## Code style
 
-_Black_ reformats entire files in place. Style configuration options are deliberately
-limited and rarely added. It doesn't take previous formatting into account, except for
-the magic trailing comma and preserving newlines. It doesn't reformat blocks that start
-with `# fmt: off` and end with `# fmt: on`, or lines that ends with `# fmt: skip`.
+_Black_ aims for consistency, generality, readability and reducing git diffs. Similar
+language constructs are formatted with similar rules. Style configuration options are
+deliberately limited and rarely added. Previous formatting is taken into account as
+little as possible, with rare exceptions like the magic trailing comma. The coding style
+used by _Black_ can be viewed as a strict subset of PEP 8.
+
+_Black_ reformats entire files in place. It doesn't reformat blocks that start with
+`# fmt: off` and end with `# fmt: on`, or lines that ends with `# fmt: skip`.
 `# fmt: on/off` have to be on the same level of indentation. It also recognizes
 [YAPF](https://github.com/google/yapf)'s block comments to the same effect, as a
 courtesy for straddling code.
@@ -18,8 +22,7 @@ running `black --preview`.
 
 _Black_ ignores previous formatting and applies uniform horizontal and vertical
 whitespace to your code. The rules for horizontal whitespace can be summarized as: do
-whatever makes `pycodestyle` happy. The coding style used by _Black_ can be viewed as a
-strict subset of PEP 8.
+whatever makes `pycodestyle` happy.
 
 As for vertical whitespace, _Black_ tries to render one full expression or simple
 statement per line. If this fits the allotted line length, great.

docs/the_black_code_style/index.rst

@@ -12,6 +12,10 @@ The Black Code Style
 While keeping the style unchanged throughout releases has always been a goal,
 the *Black* code style isn't set in stone. It evolves to accommodate for new features
 in the Python language and, occasionally, in response to user feedback.
+Large-scale style preferences presented in :doc:`current_style` are very unlikely to
+change, but minor style aspects and details might change according to the stability
+policy presented below. Ongoing style considerations are tracked on GitHub with the
+`design <https://github.com/psf/black/labels/T%3A%20design>`_ issue label.
 
 Stability Policy
 ----------------

fuzz.py

@@ -48,7 +48,7 @@ def test_idempotent_any_syntatically_valid_python(
         dst_contents = black.format_str(src_contents, mode=mode)
     except black.InvalidInput:
         # This is a bug - if it's valid Python code, as above, Black should be
-        # able to cope with it.  See issues #970, #1012, #1358, and #1557.
+        # able to cope with it.  See issues #970, #1012
         # TODO: remove this try-except block when issues are resolved.
         return
     except TokenError as e:

src/black/__init__.py

@@ -1348,7 +1348,7 @@ def get_imports_from_children(children: List[LN]) -> Generator[str, None, None]:
     return imports
 
 
-def assert_equivalent(src: str, dst: str, *, pass_num: int = 1) -> None:
+def assert_equivalent(src: str, dst: str) -> None:
     """Raise AssertionError if `src` and `dst` aren't equivalent."""
     try:
         src_ast = parse_ast(src)
@@ -1365,7 +1365,7 @@ def assert_equivalent(src: str, dst: str, *, pass_num: int = 1) -> None:
     except Exception as exc:
         log = dump_to_file("".join(traceback.format_tb(exc.__traceback__)), dst)
         raise AssertionError(
-            f"INTERNAL ERROR: Black produced invalid code on pass {pass_num}: {exc}. "
+            f"INTERNAL ERROR: Black produced invalid code: {exc}. "
             "Please report a bug on https://github.com/psf/black/issues.  "
             f"This invalid output might be helpful: {log}"
         ) from None
@@ -1376,7 +1376,7 @@ def assert_equivalent(src: str, dst: str, *, pass_num: int = 1) -> None:
         log = dump_to_file(diff(src_ast_str, dst_ast_str, "src", "dst"))
         raise AssertionError(
             "INTERNAL ERROR: Black produced code that is not equivalent to the"
-            f" source on pass {pass_num}.  Please report a bug on "
+            f" source.  Please report a bug on "
             f"https://github.com/psf/black/issues.  This diff might be helpful: {log}"
         ) from None
 

src/black/linegen.py

@@ -7,7 +7,7 @@
 
 from black.nodes import WHITESPACE, RARROW, STATEMENT, STANDALONE_COMMENT
 from black.nodes import ASSIGNMENTS, OPENING_BRACKETS, CLOSING_BRACKETS
-from black.nodes import Visitor, syms, first_child_is_arith, ensure_visible
+from black.nodes import Visitor, syms, is_arith_like, ensure_visible
 from black.nodes import is_docstring, is_empty_tuple, is_one_tuple, is_one_tuple_between
 from black.nodes import is_name_token, is_lpar_token, is_rpar_token
 from black.nodes import is_walrus_assignment, is_yield, is_vararg, is_multiline_string
@@ -156,8 +156,12 @@ def visit_suite(self, node: Node) -> Iterator[Line]:
 
     def visit_simple_stmt(self, node: Node) -> Iterator[Line]:
         """Visit a statement without nested statements."""
-        if first_child_is_arith(node):
-            wrap_in_parentheses(node, node.children[0], visible=False)
+        prev_type: Optional[int] = None
+        for child in node.children:
+            if (prev_type is None or prev_type == token.SEMI) and is_arith_like(child):
+                wrap_in_parentheses(node, child, visible=False)
+            prev_type = child.type
+
         is_suite_like = node.parent and node.parent.type in STATEMENT
         if is_suite_like:
             if self.mode.is_pyi and is_stub_body(node):
@@ -539,7 +543,7 @@ def right_hand_split(
         # there are no standalone comments in the body
         and not body.contains_standalone_comments(0)
         # and we can actually remove the parens
-        and can_omit_invisible_parens(body, line_length, omit_on_explode=omit)
+        and can_omit_invisible_parens(body, line_length)
     ):
         omit = {id(closing_bracket), *omit}
         try:

src/black/lines.py

@@ -3,7 +3,6 @@
 import sys
 from typing import (
     Callable,
-    Collection,
     Dict,
     Iterator,
     List,
@@ -22,7 +21,7 @@
 from black.nodes import STANDALONE_COMMENT, TEST_DESCENDANTS
 from black.nodes import BRACKETS, OPENING_BRACKETS, CLOSING_BRACKETS
 from black.nodes import syms, whitespace, replace_child, child_towards
-from black.nodes import is_multiline_string, is_import, is_type_comment, last_two_except
+from black.nodes import is_multiline_string, is_import, is_type_comment
 from black.nodes import is_one_tuple_between
 
 # types
@@ -530,11 +529,11 @@ def _maybe_empty_lines_for_class_or_def(
             return 0, 0
 
         if self.is_pyi:
-            if self.previous_line.depth > current_line.depth:
-                newlines = 0 if current_line.depth else 1
-            elif current_line.is_class or self.previous_line.is_class:
-                if current_line.depth:
+            if current_line.is_class or self.previous_line.is_class:
+                if self.previous_line.depth < current_line.depth:
                     newlines = 0
+                elif self.previous_line.depth > current_line.depth:
+                    newlines = 1
                 elif current_line.is_stub_class and self.previous_line.is_stub_class:
                     # No blank line between classes with an empty body
                     newlines = 0
@@ -551,6 +550,8 @@ def _maybe_empty_lines_for_class_or_def(
                     # Blank line between a block of functions (maybe with preceding
                     # decorators) and a block of non-functions
                     newlines = 1
+            elif self.previous_line.depth > current_line.depth:
+                newlines = 1
             else:
                 newlines = 0
         else:
@@ -643,7 +644,6 @@ def can_be_split(line: Line) -> bool:
 def can_omit_invisible_parens(
     line: Line,
     line_length: int,
-    omit_on_explode: Collection[LeafID] = (),
 ) -> bool:
     """Does `line` have a shape safe to reformat without optional parens around it?
 
@@ -681,12 +681,6 @@ def can_omit_invisible_parens(
 
     penultimate = line.leaves[-2]
     last = line.leaves[-1]
-    if line.magic_trailing_comma:
-        try:
-            penultimate, last = last_two_except(line.leaves, omit=omit_on_explode)
-        except LookupError:
-            # Turns out we'd omit everything.  We cannot skip the optional parentheses.
-            return False
 
     if (
         last.type == token.RPAR
@@ -708,10 +702,6 @@ def can_omit_invisible_parens(
             # unnecessary.
             return True
 
-        if line.magic_trailing_comma and penultimate.type == token.COMMA:
-            # The rightmost non-omitted bracket pair is the one we want to explode on.
-            return True
-
         if _can_omit_closing_paren(line, last=last, line_length=line_length):
             return True
 

src/black/nodes.py

@@ -4,13 +4,11 @@
 
 import sys
 from typing import (
-    Collection,
     Generic,
     Iterator,
     List,
     Optional,
     Set,
-    Tuple,
     TypeVar,
     Union,
 )
@@ -439,27 +437,6 @@ def prev_siblings_are(node: Optional[LN], tokens: List[Optional[NodeType]]) -> b
     return prev_siblings_are(node.prev_sibling, tokens[:-1])
 
 
-def last_two_except(leaves: List[Leaf], omit: Collection[LeafID]) -> Tuple[Leaf, Leaf]:
-    """Return (penultimate, last) leaves skipping brackets in `omit` and contents."""
-    stop_after: Optional[Leaf] = None
-    last: Optional[Leaf] = None
-    for leaf in reversed(leaves):
-        if stop_after:
-            if leaf is stop_after:
-                stop_after = None
-            continue
-
-        if last:
-            return leaf, last
-
-        if id(leaf) in omit:
-            stop_after = leaf.opening_bracket
-        else:
-            last = leaf
-    else:
-        raise LookupError("Last two leaves were also skipped")
-
-
 def parent_type(node: Optional[LN]) -> Optional[NodeType]:
     """
     Returns:
@@ -531,15 +508,14 @@ def first_leaf_column(node: Node) -> Optional[int]:
     return None
 
 
-def first_child_is_arith(node: Node) -> bool:
-    """Whether first child is an arithmetic or a binary arithmetic expression"""
-    expr_types = {
+def is_arith_like(node: LN) -> bool:
+    """Whether node is an arithmetic or a binary arithmetic expression"""
+    return node.type in {
         syms.arith_expr,
         syms.shift_expr,
         syms.xor_expr,
         syms.and_expr,
     }
-    return bool(node.children and node.children[0].type in expr_types)
 
 
 def is_docstring(leaf: Leaf) -> bool: