[pylint] Ignore __init__.py files in (PLC0414) (#18400)

## Summary

Ignore `__init__.py` files in `useless-import-alias` (PLC0414).
See discussion in #18365 and #6294: we want to allow redundant aliases
in `__init__.py` files, as they're almost always intentional explicit
re-exports.
Closes #18365
 Closes #6294

---------

Co-authored-by: Dylan <dylwil3@gmail.com>

crates/ruff_linter/resources/test/fixtures/pylint/import_aliasing_2/__init__.py

@@ -0,0 +1,4 @@
+import collections as collections
+from collections import OrderedDict as OrderedDict
+from . import foo as foo
+from .foo import bar as bar

crates/ruff_linter/src/preview.rs

@@ -77,3 +77,10 @@ pub(crate) const fn is_multiple_with_statements_fix_safe_enabled(
 ) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/18400
+pub(crate) const fn is_ignore_init_files_in_useless_alias_enabled(
+    settings: &LinterSettings,
+) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/pylint/mod.rs

@@ -168,6 +168,7 @@ mod tests {
     )]
     #[test_case(Rule::UselessElseOnLoop, Path::new("useless_else_on_loop.py"))]
     #[test_case(Rule::UselessImportAlias, Path::new("import_aliasing.py"))]
+    #[test_case(Rule::UselessImportAlias, Path::new("import_aliasing_2/__init__.py"))]
     #[test_case(Rule::UselessReturn, Path::new("useless_return.py"))]
     #[test_case(Rule::UselessWithLock, Path::new("useless_with_lock.py"))]
     #[test_case(Rule::UnreachableCode, Path::new("unreachable.py"))]
@@ -418,6 +419,19 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn preview_useless_import_alias() -> Result<()> {
+        let diagnostics = test_path(
+            Path::new("pylint/import_aliasing_2/__init__.py"),
+            &LinterSettings {
+                preview: PreviewMode::Enabled,
+                ..LinterSettings::for_rule(Rule::UselessImportAlias)
+            },
+        )?;
+        assert_diagnostics!(diagnostics);
+        Ok(())
+    }
+
     #[test]
     fn import_outside_top_level_with_banned() -> Result<()> {
         let diagnostics = test_path(

crates/ruff_linter/src/rules/pylint/rules/useless_import_alias.rs

@@ -4,11 +4,14 @@ use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
+use crate::preview::is_ignore_init_files_in_useless_alias_enabled;
 use crate::{Edit, Fix, FixAvailability, Violation};
 
 /// ## What it does
 /// Checks for import aliases that do not rename the original package.
 ///
+/// In [preview] this rule does not apply in `__init__.py` files.
+///
 /// ## Why is this bad?
 /// The import alias is redundant and should be removed to avoid confusion.
 ///
@@ -32,6 +35,8 @@ use crate::{Edit, Fix, FixAvailability, Violation};
 /// ```python
 /// import numpy
 /// ```
+///
+/// [preview]: https://docs.astral.sh/ruff/preview/
 #[derive(ViolationMetadata)]
 pub(crate) struct UselessImportAlias {
     required_import_conflict: bool,
@@ -67,6 +72,14 @@ pub(crate) fn useless_import_alias(checker: &Checker, alias: &Alias) {
     if alias.name.as_str() != asname.as_str() {
         return;
     }
+
+    // A re-export in __init__.py is probably intentional.
+    if checker.path().ends_with("__init__.py")
+        && is_ignore_init_files_in_useless_alias_enabled(checker.settings)
+    {
+        return;
+    }
+
     // A required import with a useless alias causes an infinite loop.
     // See https://github.com/astral-sh/ruff/issues/14283
     let required_import_conflict = checker
@@ -100,6 +113,12 @@ pub(crate) fn useless_import_from_alias(
     if alias.name.as_str() != asname.as_str() {
         return;
     }
+
+    // A re-export in __init__.py is probably intentional.
+    if checker.path().ends_with("__init__.py") {
+        return;
+    }
+
     // A required import with a useless alias causes an infinite loop.
     // See https://github.com/astral-sh/ruff/issues/14283
     let required_import_conflict = checker.settings.isort.requires_member_import(

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__PLC0414_import_aliasing_2____init__.py.snap

@@ -0,0 +1,18 @@
+---
+source: crates/ruff_linter/src/rules/pylint/mod.rs
+---
+__init__.py:1:8: PLC0414 [*] Import alias does not rename original package
+  |
+1 | import collections as collections
+  |        ^^^^^^^^^^^^^^^^^^^^^^^^^^ PLC0414
+2 | from collections import OrderedDict as OrderedDict
+3 | from . import foo as foo
+  |
+  = help: Remove import alias
+
+ℹ Unsafe fix
+1   |-import collections as collections
+  1 |+import collections
+2 2 | from collections import OrderedDict as OrderedDict
+3 3 | from . import foo as foo
+4 4 | from .foo import bar as bar

crates/ruff_linter/src/rules/pylint/snapshots/ruff_linter__rules__pylint__tests__preview_useless_import_alias.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/pylint/mod.rs
+---
+