Improvement: Remove useless else after if-return or if-raise

personal_python_ast_optimizer/parser/config.py

@@ -138,6 +138,7 @@ class OptimizationsConfig(_Config):
         "functions_safe_to_exclude_in_test_expr",
         "remove_typing_cast",
         "remove_unused_imports",
+        "remove_useless_else",
         "simplify_named_tuples",
         "vars_to_fold",
     )
@@ -152,6 +153,7 @@ def __init__(  # noqa: PLR0913
         enums_to_fold: Iterable[EnumType] | None = None,
         functions_safe_to_exclude_in_test_expr: set[str] | None = None,
         remove_unused_imports: bool = True,
+        remove_useless_else: bool = True,
         remove_typing_cast: bool = True,
         collection_concat_to_unpack: bool = False,
         fold_constants: bool = False,
@@ -171,6 +173,7 @@ def __init__(  # noqa: PLR0913
             or default_functions_safe_to_exclude_in_test_expr
         )
         self.remove_unused_imports: bool = remove_unused_imports
+        self.remove_useless_else: bool = remove_useless_else
         self.remove_typing_cast: bool = remove_typing_cast
         self.collection_concat_to_unpack: bool = collection_concat_to_unpack
         self.assume_this_machine: bool = assume_this_machine

personal_python_ast_optimizer/parser/skipper.py

@@ -526,6 +526,14 @@ def visit_If(self, node: ast.If) -> ast.AST | list[ast.stmt] | None:
 
                     parsed_node.body = parsed_node.body[0].body
 
+            elif self.optimizations_config.remove_useless_else and isinstance(
+                parsed_node.body[-1], (ast.Raise, ast.Return)
+            ):
+                denested_else: list[ast.stmt] = parsed_node.orelse
+                parsed_node.orelse = []
+                denested_else.insert(0, parsed_node)
+                return denested_else
+
         return parsed_node
 
     def visit_IfExp(self, node: ast.IfExp) -> ast.AST | None:

tests/parser/test_if.py

@@ -145,3 +145,21 @@ def test_if(before_and_after: BeforeAndAfter):
 @pytest.mark.parametrize("before_and_after", _nested_if_cases)
 def test_nested_if(before_and_after: BeforeAndAfter):
     run_minifier_and_assert_correct(before_and_after)
+
+
+def test_if_return():
+    before_and_after = BeforeAndAfter(
+        """
+def a(foo):
+    if foo > 5:
+        raise ValueError
+    elif foo < 9:
+        return 6
+    else:
+        return 7""",
+        """def a(foo):
+\tif foo>5:raise ValueError
+\tif foo<9:return 6
+\treturn 7""",
+    )
+    run_minifier_and_assert_correct(before_and_after)

version.txt

@@ -1 +1 @@
-8.0.0
+8.0.1