Convert %d if the input is a explicit int conversion

src/flynt/transform/percent_transformer.py

@@ -34,7 +34,20 @@ def is_percent_stringify(node: ast.BinOp) -> bool:
     )
 
 
+def _is_builtin_int_call(val: ast.AST) -> bool:
+    return _is_int_call(val) or _is_len_call(val)
+
+
+def _is_int_call(val: ast.AST) -> bool:
+    return (
+        isinstance(val, ast.Call)
+        and isinstance(val.func, ast.Name)
+        and val.func.id == "int"
+    )
+
+
 def _is_len_call(val: ast.AST) -> bool:
+    # assume built-in len always returns int
     return (
         isinstance(val, ast.Call)
         and isinstance(val.func, ast.Name)
@@ -65,8 +78,8 @@ def formatted_value(
         )
     fmt_spec = translate_conversion_types.get(fmt_spec, fmt_spec)
     if fmt_spec == "d":
-        # assume built-in len always returns int
-        if not _is_len_call(val):
+        # test if is a built-in that returns int
+        if not _is_builtin_int_call(val):
             if not aggressive:
                 raise ConversionRefused(
                     "Skipping %d formatting - fstrings behave differently from % formatting.",

test/test_edits.py

@@ -47,6 +47,15 @@ def test_string_specific_len(state: State):
     assert s_out == s_expected
 
 
+def test_dont_wrap_int(state: State):
+    s_in = """print('Int cast %d' % int(18.81))"""
+    s_expected = """print(f'Int cast {int(18.81)}')"""
+
+    state.aggressive = True
+    s_out, count = code_editor.fstringify_code_by_line(s_in, state)
+    assert s_out == s_expected
+
+
 def test_dont_wrap_len(state: State):
     s_in = """print('List length %d' % len(sys.argv))"""
     s_expected = """print(f'List length {len(sys.argv)}')"""