Type alias stub for formatter (#5880)

**Summary** This replaces the `todo!()` with a type alias stub in the
formatter. I added the tests from
704eb40108/parser/src/parser.rs (L901-L936)
as ruff python formatter tests.

**Test Plan** None, testing is part of the actual implementation

crates/ruff_python_formatter/src/generated.rs

@@ -361,6 +361,46 @@ impl<'ast> IntoFormat<PyFormatContext<'ast>> for ast::StmtDelete {
     }
 }
 
+impl FormatRule<ast::StmtTypeAlias, PyFormatContext<'_>>
+    for crate::statement::stmt_type_alias::FormatStmtTypeAlias
+{
+    #[inline]
+    fn fmt(
+        &self,
+        node: &ast::StmtTypeAlias,
+        f: &mut Formatter<PyFormatContext<'_>>,
+    ) -> FormatResult<()> {
+        FormatNodeRule::<ast::StmtTypeAlias>::fmt(self, node, f)
+    }
+}
+impl<'ast> AsFormat<PyFormatContext<'ast>> for ast::StmtTypeAlias {
+    type Format<'a> = FormatRefWithRule<
+        'a,
+        ast::StmtTypeAlias,
+        crate::statement::stmt_type_alias::FormatStmtTypeAlias,
+        PyFormatContext<'ast>,
+    >;
+    fn format(&self) -> Self::Format<'_> {
+        FormatRefWithRule::new(
+            self,
+            crate::statement::stmt_type_alias::FormatStmtTypeAlias::default(),
+        )
+    }
+}
+impl<'ast> IntoFormat<PyFormatContext<'ast>> for ast::StmtTypeAlias {
+    type Format = FormatOwnedWithRule<
+        ast::StmtTypeAlias,
+        crate::statement::stmt_type_alias::FormatStmtTypeAlias,
+        PyFormatContext<'ast>,
+    >;
+    fn into_format(self) -> Self::Format {
+        FormatOwnedWithRule::new(
+            self,
+            crate::statement::stmt_type_alias::FormatStmtTypeAlias::default(),
+        )
+    }
+}
+
 impl FormatRule<ast::StmtAssign, PyFormatContext<'_>>
     for crate::statement::stmt_assign::FormatStmtAssign
 {

crates/ruff_python_formatter/src/statement/mod.rs

@@ -27,6 +27,7 @@ pub(crate) mod stmt_raise;
 pub(crate) mod stmt_return;
 pub(crate) mod stmt_try;
 pub(crate) mod stmt_try_star;
+pub(crate) mod stmt_type_alias;
 pub(crate) mod stmt_while;
 pub(crate) mod stmt_with;
 pub(crate) mod suite;
@@ -64,7 +65,7 @@ impl FormatRule<Stmt, PyFormatContext<'_>> for FormatStmt {
             Stmt::Pass(x) => x.format().fmt(f),
             Stmt::Break(x) => x.format().fmt(f),
             Stmt::Continue(x) => x.format().fmt(f),
-            Stmt::TypeAlias(_) => todo!(),
+            Stmt::TypeAlias(x) => x.format().fmt(f),
         }
     }
 }

crates/ruff_python_formatter/src/statement/stmt_type_alias.rs

@@ -0,0 +1,17 @@
+use crate::{not_yet_implemented_custom_text, FormatNodeRule, PyFormatter};
+use ruff_formatter::{write, Buffer, FormatResult};
+use rustpython_parser::ast::StmtTypeAlias;
+
+#[derive(Default)]
+pub struct FormatStmtTypeAlias;
+
+impl FormatNodeRule<StmtTypeAlias> for FormatStmtTypeAlias {
+    fn fmt_fields(&self, _item: &StmtTypeAlias, f: &mut PyFormatter) -> FormatResult<()> {
+        write!(
+            f,
+            [not_yet_implemented_custom_text(
+                "type NOT_YET_IMPLEMENTED_type_alias = int"
+            )]
+        )
+    }
+}