make literally any import from any submodule a re-export unless renamed

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/lambda.options.json

@@ -1,8 +0,0 @@
-[
-  {
-    "preview": "disabled"
-  },
-  {
-    "preview": "enabled"
-  }
-]

crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/lambda.py

@@ -125,13 +125,6 @@ lambda a, /, c: a
     *x: x
 )
 
-(
-    lambda
-    # comment
-    *x,
-    **y: x
-)
-
 (
     lambda
     # comment 1
@@ -142,17 +135,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda
-    # comment 1
-    *
-    # comment 2
-    x,
-    **y:
-    # comment 3
-    x
-)
-
 (
     lambda # comment 1
     * # comment 2
@@ -160,14 +142,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda # comment 1
-        * # comment 2
-        x,
-        y: # comment 3
-    x
-)
-
 lambda *x\
     :x
 
@@ -222,17 +196,6 @@ lambda: ( # comment
     x
 )
 
-(
-    lambda  # 1
-    # 2
-    x,  # 3
-    # 4
-    y
-    :  # 5
-    # 6
-    x
-)
-
 (
     lambda
     x,
@@ -241,71 +204,6 @@ lambda: ( # comment
     z
 )
 
-
-# Leading
-lambda x: (
-    lambda y: lambda z: x
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + z  # Trailing
-)  # Trailing
-
-
-# Leading
-lambda x: lambda y: lambda z: [
-    x,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    z
-] # Trailing
-# Trailing
-
 lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs), e=1, f=2, g=2: d
 
 # Regression tests for https://github.com/astral-sh/ruff/issues/8179

crates/ruff_python_formatter/src/expression/expr_lambda.rs

@@ -4,7 +4,6 @@ use ruff_python_ast::ExprLambda;
 use ruff_text_size::Ranged;
 
 use crate::comments::dangling_comments;
-use crate::comments::leading_comments;
 use crate::expression::parentheses::{NeedsParentheses, OptionalParentheses};
 use crate::other::parameters::ParametersParentheses;
 use crate::prelude::*;
@@ -34,45 +33,24 @@ impl FormatNodeRule<ExprLambda> for FormatExprLambda {
 
             if dangling_before_parameters.is_empty() {
                 write!(f, [space()])?;
+            } else {
+                write!(f, [dangling_comments(dangling_before_parameters)])?;
             }
 
-            group(&format_with(|f: &mut PyFormatter| {
-                if f.context().node_level().is_parenthesized()
-                    && (parameters.len() > 1 || !dangling_before_parameters.is_empty())
-                {
-                    let end_of_line_start = dangling_before_parameters
-                        .partition_point(|comment| comment.line_position().is_end_of_line());
-                    let (same_line_comments, own_line_comments) =
-                        dangling_before_parameters.split_at(end_of_line_start);
+            write!(
+                f,
+                [parameters
+                    .format()
+                    .with_options(ParametersParentheses::Never)]
+            )?;
 
-                    dangling_comments(same_line_comments).fmt(f)?;
+            write!(f, [token(":")])?;
 
-                    write![
-                        f,
-                        [
-                            soft_line_break(),
-                            leading_comments(own_line_comments),
-                            parameters
-                                .format()
-                                .with_options(ParametersParentheses::Never),
-                        ]
-                    ]
-                } else {
-                    parameters
-                        .format()
-                        .with_options(ParametersParentheses::Never)
-                        .fmt(f)
-                }?;
-
-                write!(f, [token(":")])?;
-
-                if dangling_after_parameters.is_empty() {
-                    write!(f, [space()])
-                } else {
-                    write!(f, [dangling_comments(dangling_after_parameters)])
-                }
-            }))
-            .fmt(f)?;
+            if dangling_after_parameters.is_empty() {
+                write!(f, [space()])?;
+            } else {
+                write!(f, [dangling_comments(dangling_after_parameters)])?;
+            }
         } else {
             write!(f, [token(":")])?;
 

crates/ruff_python_formatter/src/other/parameters.rs

@@ -241,7 +241,7 @@ impl FormatNodeRule<Parameters> for FormatParameters {
         let num_parameters = item.len();
 
         if self.parentheses == ParametersParentheses::Never {
-            write!(f, [format_inner, dangling_comments(dangling)])
+            write!(f, [group(&format_inner), dangling_comments(dangling)])
         } else if num_parameters == 0 {
             let mut f = WithNodeLevel::new(NodeLevel::ParenthesizedExpression, f);
             // No parameters, format any dangling comments between `()`

crates/ruff_python_formatter/tests/snapshots/format@expression__lambda.py.snap

@@ -1,6 +1,7 @@
 ---
 source: crates/ruff_python_formatter/tests/fixtures.rs
 input_file: crates/ruff_python_formatter/resources/test/fixtures/ruff/expression/lambda.py
+snapshot_kind: text
 ---
 ## Input
 ```python
@@ -131,13 +132,6 @@ lambda a, /, c: a
     *x: x
 )
 
-(
-    lambda
-    # comment
-    *x,
-    **y: x
-)
-
 (
     lambda
     # comment 1
@@ -148,17 +142,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda
-    # comment 1
-    *
-    # comment 2
-    x,
-    **y:
-    # comment 3
-    x
-)
-
 (
     lambda # comment 1
     * # comment 2
@@ -166,14 +149,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda # comment 1
-        * # comment 2
-        x,
-        y: # comment 3
-    x
-)
-
 lambda *x\
     :x
 
@@ -228,17 +203,6 @@ lambda: ( # comment
     x
 )
 
-(
-    lambda  # 1
-    # 2
-    x,  # 3
-    # 4
-    y
-    :  # 5
-    # 6
-    x
-)
-
 (
     lambda
     x,
@@ -247,71 +211,6 @@ lambda: ( # comment
     z
 )
 
-
-# Leading
-lambda x: (
-    lambda y: lambda z: x
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + y
-                        + z  # Trailing
-)  # Trailing
-
-
-# Leading
-lambda x: lambda y: lambda z: [
-    x,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    z
-] # Trailing
-# Trailing
-
 lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs), e=1, f=2, g=2: d
 
 # Regression tests for https://github.com/astral-sh/ruff/issues/8179
@@ -338,22 +237,7 @@ def a():
 
 ```
 
-## Outputs
-### Output 1
-```
-indent-style               = space
-line-width                 = 88
-indent-width               = 4
-quote-style                = Double
-line-ending                = LineFeed
-magic-trailing-comma       = Respect
-docstring-code             = Disabled
-docstring-code-line-width  = "dynamic"
-preview                    = Disabled
-target_version             = 3.10
-source_type                = Python
-```
-
+## Output
 ```python
 # Leading
 lambda x: x  # Trailing
@@ -417,8 +301,7 @@ a = (
 )
 
 a = (
-    lambda 
-    x,  # Dangling
+    lambda x,  # Dangling
     y: 1
 )
 
@@ -484,13 +367,6 @@ lambda a, /, c: a
     *x: x
 )
 
-(
-    lambda
-    # comment
-    *x,
-    **y: x
-)
-
 (
     lambda
     # comment 1
@@ -500,16 +376,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda
-    # comment 1
-    # comment 2
-    *x,
-    **y:
-    # comment 3
-    x
-)
-
 (
     lambda  # comment 1
     # comment 2
@@ -517,14 +383,6 @@ lambda a, /, c: a
     x
 )
 
-(
-    lambda  # comment 1
-    # comment 2
-    *x,
-    y:  # comment 3
-    x
-)
-
 lambda *x: x
 
 (
@@ -577,87 +435,11 @@ lambda: (  # comment
 )
 
 (
-    lambda  # 1
-    # 2
-    x,  # 3
-    # 4
-    y:  # 5
-    # 6
-    x
-)
-
-(
-    lambda 
-    x,
+    lambda x,
     # comment
     y: z
 )
 
-
-# Leading
-lambda x: (
-    lambda y: lambda z: x
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + z  # Trailing
-)  # Trailing
-
-
-# Leading
-lambda x: lambda y: lambda z: [
-    x,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    z,
-]  # Trailing
-# Trailing
-
 lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
     *args, **kwargs
 ), e=1, f=2, g=2: d
@@ -669,8 +451,7 @@ def a():
         c,
         d,
         e,
-        f=lambda 
-        self,
+        f=lambda self,
         *args,
         **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs),
     )
@@ -681,365 +462,7 @@ def a():
         c,
         d,
         e,
-        f=lambda 
-        self,
-        araa,
-        kkkwargs,
-        aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,
-        args,
-        kwargs,
-        e=1,
-        f=2,
-        g=2: d,
-        g=10,
-    )
-```
-
-
-### Output 2
-```
-indent-style               = space
-line-width                 = 88
-indent-width               = 4
-quote-style                = Double
-line-ending                = LineFeed
-magic-trailing-comma       = Respect
-docstring-code             = Disabled
-docstring-code-line-width  = "dynamic"
-preview                    = Enabled
-target_version             = 3.10
-source_type                = Python
-```
-
-```python
-# Leading
-lambda x: x  # Trailing
-# Trailing
-
-# Leading
-lambda x, y: x  # Trailing
-# Trailing
-
-# Leading
-lambda x, y: x, y  # Trailing
-# Trailing
-
-# Leading
-lambda x, /, y: x  # Trailing
-# Trailing
-
-# Leading
-lambda x: lambda y: lambda z: x  # Trailing
-# Trailing
-
-# Leading
-lambda x: lambda y: lambda z: (x, y, z)  # Trailing
-# Trailing
-
-# Leading
-lambda x: lambda y: lambda z: (x, y, z)  # Trailing
-# Trailing
-
-# Leading
-lambda x: lambda y: lambda z: (
-    x,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    z,
-)  # Trailing
-# Trailing
-
-a = (
-    lambda:  # Dangling
-    1
-)
-
-a = (
-    lambda 
-    x,  # Dangling
-    y: 1
-)
-
-# Regression test: lambda empty arguments ranges were too long, leading to unstable
-# formatting
-(
-    lambda: (  #
-    ),
-)
-
-
-# lambda arguments don't have parentheses, so we never add a magic trailing comma ...
-def f(
-    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb = lambda x: y,
-):
-    pass
-
-
-# ...but we do preserve a trailing comma after the arguments
-a = lambda b,: 0
-
-lambda a,: 0
-lambda *args,: 0
-lambda **kwds,: 0
-lambda a, *args,: 0
-lambda a, **kwds,: 0
-lambda *args, b,: 0
-lambda *, b,: 0
-lambda *args, **kwds,: 0
-lambda a, *args, b,: 0
-lambda a, *, b,: 0
-lambda a, *args, **kwds,: 0
-lambda *args, b, **kwds,: 0
-lambda *, b, **kwds,: 0
-lambda a, *args, b, **kwds,: 0
-lambda a, *, b, **kwds,: 0
-lambda a, /: a
-lambda a, /, c: a
-
-# Dangling comments without parameters.
-(
-    lambda:  # 3
-    None
-)
-
-(
-    lambda:
-    # 3
-    None
-)
-
-(
-    lambda:  # 1
-    # 2
-    # 3
-    # 4
-    None  # 5
-)
-
-(
-    lambda
-    # comment
-    *x: x
-)
-
-(
-    lambda
-    # comment
-    *x,
-    **y: x
-)
-
-(
-    lambda
-    # comment 1
-    # comment 2
-    *x:
-    # comment 3
-    x
-)
-
-(
-    lambda
-    # comment 1
-    # comment 2
-    *x,
-    **y:
-    # comment 3
-    x
-)
-
-(
-    lambda  # comment 1
-    # comment 2
-    *x:  # comment 3
-    x
-)
-
-(
-    lambda  # comment 1
-    # comment 2
-    *x,
-    y:  # comment 3
-    x
-)
-
-lambda *x: x
-
-(
-    lambda
-    # comment
-    *x: x
-)
-
-lambda: (  # comment
-    x
-)
-
-(
-    lambda:  # comment
-    x
-)
-
-(
-    lambda:
-    # comment
-    x
-)
-
-(
-    lambda:  # comment
-    x
-)
-
-(
-    lambda:
-    # comment
-    x
-)
-
-(
-    lambda:  # comment
-    (  # comment
-        x
-    )
-)
-
-(
-    lambda  # 1
-    # 2
-    x:  # 3
-    # 4
-    # 5
-    # 6
-    x
-)
-
-(
-    lambda  # 1
-    # 2
-    x,  # 3
-    # 4
-    y:  # 5
-    # 6
-    x
-)
-
-(
-    lambda 
-    x,
-    # comment
-    y: z
-)
-
-
-# Leading
-lambda x: (
-    lambda y: lambda z: x
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + y
-    + z  # Trailing
-)  # Trailing
-
-
-# Leading
-lambda x: lambda y: lambda z: [
-    x,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    y,
-    z,
-]  # Trailing
-# Trailing
-
-lambda self, araa, kkkwargs=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
-    *args, **kwargs
-), e=1, f=2, g=2: d
-
-
-# Regression tests for https://github.com/astral-sh/ruff/issues/8179
-def a():
-    return b(
-        c,
-        d,
-        e,
-        f=lambda 
-        self,
-        *args,
-        **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs),
-    )
-
-
-def a():
-    return b(
-        c,
-        d,
-        e,
-        f=lambda 
-        self,
+        f=lambda self,
         araa,
         kkkwargs,
         aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa,

crates/ty_python_semantic/resources/mdtest/import/conventions.md

@@ -265,12 +265,10 @@ Similarly, for an `__init__.pyi` (stub) file, importing a non-exported name shou
 but the inference would be `Unknown`.
 
 ```py
-# error: 15 "Module `a` has no member `Foo`"
-# error: 20 "Module `a` has no member `c`"
 from a import Foo, c, foo
 
-reveal_type(Foo)  # revealed: Unknown
-reveal_type(c)  # revealed: Unknown
+reveal_type(Foo)  # revealed: <class 'Foo'>
+reveal_type(c)  # revealed: <module 'a.b.c'>
 reveal_type(foo)  # revealed: <module 'a.foo'>
 ```
 

crates/ty_python_semantic/resources/mdtest/import/nonstandard_conventions.md

@@ -25,7 +25,7 @@ This file currently covers the following details:
     wild. Equivalent imports like `from whatever.thispackage import a` also introduce a re-export
     (this has essentially zero ecosystem impact, we just felt it was more consistent). The only way
     to opt out of this is to rename the import to something else (`from . import a as b`).
-    `from .a import b` and equivalent does *not* introduce a re-export.
+    `from .a import b` and equivalent also introduces a re-export, yes this is chaos.
 
 Note: almost all tests in here have a stub and non-stub version, because we're interested in both
 defining symbols *at all* and re-exporting them.
@@ -247,10 +247,8 @@ reveal_type(mypackage.submodule)  # revealed: Unknown
 reveal_type(mypackage.submodule.nested)  # revealed: Unknown
 # error: "has no member `submodule`"
 reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
-# error: "has no member `nested`"
-reveal_type(mypackage.nested)  # revealed: Unknown
-# error: "has no member `nested`"
-reveal_type(mypackage.nested.X)  # revealed: Unknown
+reveal_type(mypackage.nested)  # revealed: <module 'mypackage.submodule.nested'>
+reveal_type(mypackage.nested.X)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -325,10 +323,8 @@ reveal_type(mypackage.submodule)  # revealed: Unknown
 reveal_type(mypackage.submodule.nested)  # revealed: Unknown
 # error: "has no member `submodule`"
 reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
-# error: "has no member `nested`"
-reveal_type(mypackage.nested)  # revealed: Unknown
-# error: "has no member `nested`"
-reveal_type(mypackage.nested.X)  # revealed: Unknown
+reveal_type(mypackage.nested)  # revealed: <module 'mypackage.submodule.nested'>
+reveal_type(mypackage.nested.X)  # revealed: int
 ```
 
 ### In Non-Stub

crates/ty_python_semantic/src/semantic_index/builder.rs

@@ -1484,6 +1484,9 @@ impl<'ast> Visitor<'ast> for SemanticIndexBuilder<'_, 'ast> {
                         && !self.seen_submodule_imports.contains(direct_submodule)
                         && self.current_scope().is_global()
                     {
+                        // Record that this is equivalent to `from .a import ...`
+                        is_self_import = true;
+
                         self.seen_submodule_imports
                             .insert(direct_submodule.to_owned());