Formatter: stub files only have one empty lines between top level items

[konstin]

Black only formats one empty line between top level items in stub files (.pyi), while it uses two empty lines in regular python files. When single line classes, method and functions of the same kind that are stubbed out with ellipses follow each they don't get any empty lines.

scratch.py

class A:
    def __init__(self):
        pass


class B:
    def __init__(self):
        pass


def foo():
    pass


class Del(expr_context):
    ...


class Load(expr_context):
    ...


class Store(expr_context):
    ...

scratch.pyi

class A:
    def __init__(self):
        pass

class B:
    def __init__(self):
        pass

def foo():
    pass

class Del(expr_context): ...
class Load(expr_context): ...
class Store(expr_context): ...

The relevant code is below, which doesn't have access to whether it's in a stub file or not yet.

ruff/crates/ruff_python_formatter/src/statement/suite.rs

Line 72 in f5f8eb3

&format_args![empty_line(), empty_line()],

[MichaReiser]

Note: This requires knowing the file type during formatting by passing it to the format context.

[konstin]

PyFormatOptions now has a source_type field